Multi-Thread - Utilizing Multicores
Does Crystal Report XI do multi-threading? I upgrading computers at work and I'm trying to get as much speed out ofthe computers as possible. The main mfg computer using Crystal Reports Daily and I'm looking at upgrading it to Quad Core 2.66Ghz. But I have found out that many of the software packages we use are unable to utilize the core.
Will Crystal Reports?
Thanks,
I use a piece of software called Planit Solid which uses Crystal Reprts to create is cut sheets with in Solid. So I'm limited.
Similar Messages
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How to write a multi threaded Cache Event Listener
I have a distributed data cache called tokenCache for my application. I have also added a mapListener to this cache to listen to a particular kind of events.
tokenCache.addMapListener((MapListener) new TokenCacheListenerBean(), new MapEventFilter(tokenFilter), false);
So bascially everytime a token (The domain object of this cache) is updated the entryUpdated() method in my EJB TokenCacheListenerBean is invoked.
The issue I have though is that, from what I observe on running my code is that the Cache Listener is single threaded. So if two Token Objects on my tokenCache are updated,
lets say Token Object A and Token Object B one after the other, the entryUpdated() method in my EJB is invoked for Token Object A and once the invocation is complete
then the entryUpdated() method is invoked again for Token Object B(). At a given point of time there is only one instance of TokenCacheListenerBean EJB. Is there a way to
make this happen in multi-threaded manner ?
Is there a configuration setting somewhere which allows multiple CacheListeners to be instantiated at a given point of time ?
TokenCacheListenerBean EJB_
package oracle.communications.activation.asap.ace;
import java.util.Iterator;
import java.util.Set;
import java.util.logging.Logger;
import javax.ejb.Stateless;
import com.tangosol.net.NamedCache;
import com.tangosol.util.MapEvent;
import com.tangosol.util.MapListener;
import com.tangosol.util.ValueUpdater;
import com.tangosol.util.extractor.PofExtractor;
import com.tangosol.util.extractor.PofUpdater;
import com.tangosol.util.filter.EqualsFilter;
import com.tangosol.util.filter.LikeFilter;
import com.tangosol.util.filter.LimitFilter;
import com.tangosol.util.processor.UpdaterProcessor;
* Session Bean implementation class TokenCacheListenerBean
@Stateless
public class TokenCacheListenerBean implements TokenCacheListenerBeanRemote, TokenCacheListenerBeanLocal, MapListener {
NamedCache asdlCache;
NamedCache tokenCache;
private final int PAGE_SIZE = 1;
private static Logger logger = Logger.getLogger(ConnectionManager.class.getName());;
* An instance of the JCAModeler EJB, represents the JCA-JNEP
JCAModeler jcaBean;
* Default constructor.
public TokenCacheListenerBean() {
// TODO Auto-generated constructor stub
public void entryDeleted(MapEvent Event) {
public void entryInserted(MapEvent Event) {
public void entryUpdated(MapEvent Event) {
Token newToken = (Token) Event.getNewValue();
Token oldToken = (Token) Event.getOldValue();
if ((oldToken.getState() == Token.TOKEN_RESERVED)
&& (newToken.getState()== Token.TOKEN_AVAILABLE)) {
String networkID = newToken.getNeID();
asdlCache = AceCacheFactory.getCache("asdlCache");
tokenCache = AceCacheFactory.getCache("tokenCache");
EqualsFilter filterNE = new EqualsFilter(new PofExtractor(String.class,Asdl.NETWORKID), networkID);
LimitFilter limitFilter = new LimitFilter(filterNE, PAGE_SIZE);
Set removeASDL = asdlCache.keySet(limitFilter);
Iterator asdlIterator = removeASDL.iterator();
if (asdlIterator.hasNext()) {
logger.info(printASDLCache());
ValueUpdater updater = new PofUpdater(Token.STATE);
System.out.println("Token ID:" + newToken.getTokenID());
UpdaterProcessor updaterProcessor = new UpdaterProcessor(updater, Integer.toString(Token.TOKEN_RESERVED));
tokenCache.invoke(newToken.getTokenID(), updaterProcessor);
jcaBean = new JCAModeler(tokenCache);
Object asdlID = asdlIterator.next();
Asdl provisionAsdl = (Asdl) asdlCache.get(asdlID);
asdlCache.remove(asdlID);
jcaBean.provision(provisionAsdl, newToken.getTokenID());
logger.info(ConnectionManager.printTokenCache());
logger.info(printASDLCache());
}Here is what I am asking!
I have added 2 listeners (Listener A and Listener B) which each listen on for changes made to 2 different token Cache Objects (Token A and Token B).
for (i = 0; i < 2 ; i++) {
Token tokenAdded = new Token(UUID.randomUUID().toString(),TOKEN_AVAILABLE, networkID);
tokenCache.put(tokenAdded.getTokenID(), tokenAdded);
tokenCache.addMapListener((MapListener) new TokenCacheListener(), tokenAdded.getTokenID(), false);
Now assume that updates are made to Token A and Token B simuntaneosly.
Why do i observe in my diagnostic messages that only one Listener is invoked at a given point of time.
Which means I see Listener A getting invoked and then once invocation of Listener A is complete I see Listener B bieng invoked.
Ideally I would want both listeners to be invoked simultaneously rather than in a one off fashion.
Here is the code for my token cache Listener
package oracle.communications.activation.asap.ace;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.tangosol.net.CacheFactory;
import com.tangosol.net.NamedCache;
import com.tangosol.util.AbstractMapListener;
import com.tangosol.util.Filter;
import com.tangosol.util.MapEvent;
import com.tangosol.util.MapListener;
import com.tangosol.util.ObservableMap;
import com.tangosol.util.ValueUpdater;
import com.tangosol.util.extractor.PofExtractor;
import com.tangosol.util.extractor.PofUpdater;
import com.tangosol.util.filter.AndFilter;
import com.tangosol.util.filter.EqualsFilter;
import com.tangosol.util.filter.LikeFilter;
import com.tangosol.util.filter.LimitFilter;
import com.tangosol.util.processor.UpdaterProcessor;
public class TokenCacheListener extends AbstractMapListener {
NamedCache asdlCache;
NamedCache tokenCache;
AceCacheFactory cacheFactoryBean = new AceCacheFactory();
private final int PAGE_SIZE = 1;
private static Logger logger = Logger.getLogger(ConnectionManager.class
.getName());;
* An instance of the JCAModeler EJB, represents the JCA-JNEP
JCAModeler jcaBean;
* This is a utility method and prints the tokens cache.
public String printTokenCache() {
NamedCache tokenCache = cacheFactoryBean.getCache("tokenCache");
LikeFilter tokenList = new LikeFilter(new PofExtractor(String.class,
Token.STATE), "%", (char) 0, false);
Set keySet = tokenCache.keySet(tokenList);
StringBuffer cachedTokenList = new StringBuffer("\n################################## Token(s) Cache ##################################");
int counter = 1;
for (Object tokenInCache: keySet) {
Token tokenObject = (Token) tokenCache.get(tokenInCache.toString());
cachedTokenList.append("\nS.NO:" + (counter++)
+ "\t ID:" + tokenInCache.toString()
+ "\t State:" + Token.tokenToString(tokenObject.getState()));
cachedTokenList.append("\n####################################################################################");
return cachedTokenList.toString();
* This method is a utility method and it prints all the ASDL(s) currently present on the
* asdlCache.
private String printASDLCache() {
NamedCache asdlCache = cacheFactoryBean.getCache("asdlCache");
LikeFilter asdlList = new LikeFilter(new PofExtractor(String.class,
Asdl.NETWORKID), "%", (char) 0, false);
Set keySet = asdlCache.keySet(asdlList);
StringBuffer cachedASDLList = new StringBuffer("\n################ ASDL Cache ######## ########");
int counter = 1;
for (Object asdlInCache: keySet) {
cachedASDLList.append("\nS.NO:" + (counter++) + "\t ID:" + asdlInCache.toString());
cachedASDLList.append("\n################ ASDL Cache ######## ########\n");
return cachedASDLList.toString();
public TokenCacheListener() {
public void checkASDLCache(MapEvent Event) {
// Not currently used
public void entryUpdated(MapEvent Event) {
Token newToken = (Token) Event.getNewValue();
Token oldToken = (Token) Event.getOldValue();
logger.info("\n=============================================================================================="
+ "\nTOKEN CACHE LISTENER"
+ "\n=============================================================================================="
+ printTokenCache()
+ "\n==============================================================================================");
if ((oldToken.getState() == Token.TOKEN_RESERVED)
&& (newToken.getState()== Token.TOKEN_AVAILABLE)) {
String networkID = newToken.getNeID();
asdlCache = cacheFactoryBean.getCache("asdlCache");
tokenCache = cacheFactoryBean.getCache("tokenCache");
EqualsFilter filterNE = new EqualsFilter(new PofExtractor(String.class,Asdl.NETWORKID), networkID);
LimitFilter limitFilter = new LimitFilter(filterNE, PAGE_SIZE);
Set removeASDL = asdlCache.keySet(limitFilter);
Iterator asdlIterator = removeASDL.iterator();
if (asdlIterator.hasNext()) {
logger.info(printASDLCache());
ValueUpdater updater = new PofUpdater(Token.STATE);
System.out.println("Token ID:" + newToken.getTokenID());
UpdaterProcessor updaterProcessor = new UpdaterProcessor(updater, Integer.toString(Token.TOKEN_RESERVED));
tokenCache.invoke(newToken.getTokenID(), updaterProcessor);
jcaBean = new JCAModeler(tokenCache);
Object asdlID = asdlIterator.next();
Asdl provisionAsdl = (Asdl) asdlCache.get(asdlID);
asdlCache.remove(asdlID);
jcaBean.provision(provisionAsdl, newToken.getTokenID());
logger.info(printTokenCache());
logger.info(printASDLCache());
I only see one instance of this listener alive at any given point of time.
Edited by: 807103 on Nov 3, 2011 1:00 PM
Edited by: 807103 on Nov 3, 2011 1:12 PM -
Multi Thread Server over TCP/IP
Multi Thread Server over TCP/IP. Does it work?
In my box it works only over IPC protocol.
nullS C Maturi (guest) wrote:
: Mark Malakanov (guest) wrote:
: : Multi Thread Server over TCP/IP. Does it work?
: : In my box it works only over IPC protocol.
: Mark,
: Multi threaded server over TCP/IP will not work with
: the current distribution of Oracle 8.0.5 on Linux.
: This is corrected and a patch would be released soon.
: Maturi
tcp 0 0 bock.nettek-ll:listener bock.nettek-
llc.co:4196 ESTABLISHED
tcp 0 0 bock.nettek-llc.co:4196 bock.nettek-
ll:listener ESTABLISHED
(I have serveral of these)
TNS Ping Utility for Linux: Version 8.0.5.0.0 - Production on 07-
JAN-99 18:45:52
(c) Copyright 1997 Oracle Corporation. All rights reserved.
Attempting to contact (ADDRESS=(PROTOCOL=TCP)(HOST=localhost)
(PORT=1521))
OK (440 msec)
...and from my install log you see that I selected MTS:
-[ YESNO
Q> Would you like MTS (Multi-Threaded Server) configured
and the SQL*Net$
A> TRUE
Please explain? Will TCP/IP MTS work via the loopback adapter
only? So far I have not tried a remote TCP/IP connection.
-STEVEl
null -
What's wrong with my multi-threaded Matrix Mult. code? 1 thread is fastest
For some reason, 1 thread performs the best. What's wrong with my implementation?
import java.util.Random;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class Matrix {
private int values[][];
private int rows;
private int columns;
public Matrix(int r, int c) {
this.rows = r;
this.columns = c;
this.values = new int[r][c];
private void randomize() {
Random generator = new Random();
for (int r = 0; r < this.rows; r++) {
for (int c = 0; c < this.columns; c++) {
this.values[r][c] = generator.nextInt(10);
public String toString() {
String out = "";
for (int r = 0; r < this.rows; r++) {
for (int c = 0; c < this.columns; c++) {
if (c == 0) out += "[";
else out += "\t";
out += this.values[r][c];
out += "]\n";
return out;
public boolean equals(Object obj) {
Matrix other = (Matrix) obj;
if (this.columns != other.columns || this.rows != other.rows) {
return false;
for (int r = 0; r < this.rows; r++) {
for (int c = 0; c < this.columns; c++) {
if (this.values[r][c] != other.values[r][c]) {
return false;
return true;
// matrix multiplication using single thread
public Matrix times(Matrix other) {
assert(this.columns == other.rows);
Matrix out = new Matrix(this.rows, other.columns);
for (int r = 0; r < this.rows; r++) {
for (int c = 0; c < other.columns; c++) {
int dotProduct = 0;
for (int z = 0; z < this.columns; z++) {
dotProduct += this.values[r][z] * other.values[z][c];
out.values[r][c] = dotProduct;
return out;
// matrix multiplication with many threads
public Matrix ptimes(Matrix other, int numberOfThreads) throws InterruptedException { // parallel
assert(this.columns == other.rows);
Matrix out = new Matrix(this.rows, other.columns);
ExecutorService threadExecutor = Executors.newFixedThreadPool(numberOfThreads);
for (int r = 0; r < this.rows; r++) {
for (int c = 0; c < other.columns; c++) {
threadExecutor.execute(new HelperThread(r, c, this, other, out));
threadExecutor.shutdown();
threadExecutor.awaitTermination(2, TimeUnit.DAYS);
return out;
private class HelperThread implements Runnable {
private int row;
private int col;
private Matrix a;
private Matrix b;
private Matrix out;
HelperThread(int r, int c, Matrix a, Matrix b, Matrix o) {
this.row = r;
this.col = c;
this.a = a;
this.b = b;
this.out = o;
public void run() {
int dotProduct = 0;
for (int z = 0; z < a.columns; z++) {
dotProduct += this.a.values[row][z] * this.b.values[z][col];
this.out.values[row][col] = dotProduct;
public static void main(String[] args) throws InterruptedException {
int size = 100;
Matrix a = new Matrix(size, size);
a.randomize();
Matrix b = new Matrix(size, size);
b.randomize();
for (int t = 1; t < 15; t++) {
long start = new Date().getTime();
System.out.print(t + " threads: ");
Matrix c = a.ptimes(b, t);
//System.out.println(c);
long finish = new Date().getTime();
System.out.println((finish - start) + " milliseconds");
Matrix d = a.times(b);
assert(c.equals(d));
}This one is even faster. On my dual core I get:
Warmup
Single Threaded
5.20616 milliseconds
5.52872 milliseconds
5.12708 milliseconds
5.59048 milliseconds
5.16104 milliseconds
5.1838 milliseconds
5.37104 milliseconds
5.1788 milliseconds
5.18636 milliseconds
5.15736 milliseconds
Multi Threaded with 2 threads
3.22184 milliseconds
2.86552 milliseconds
2.86284 milliseconds
3.67032 milliseconds
3.08032 milliseconds
2.97388 milliseconds
2.93084 milliseconds
3.44012 milliseconds
2.89744 milliseconds
2.88136 milliseconds
As you can see the Multi-Threaded versions are now faster.
// matrix multiplication with many threads
ExecutorService threadExecutor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
public Matrix ptimes(Matrix other) throws InterruptedException, ExecutionException {
assert (this.columns == other.rows);
Matrix out = new Matrix(this.rows, other.columns);
Future futures[] = new Future[rows];
for (int r = 0; r < this.rows; r++) {
futures[r] = threadExecutor.submit(new HelperThread(r, this, other, out));
for(Future f : futures) {
f.get();
return out;
private class HelperThread implements Callable<Object> {
private int row;
private Matrix a;
private Matrix b;
private Matrix out;
HelperThread(int r, Matrix a, Matrix b, Matrix o) {
this.row = r;
this.a = a;
this.b = b;
this.out = o;
public String call() throws Exception {
int dotProduct = 0;
for (int c = 0; c < b.columns; c++) {
for (int z = 0; z < a.columns; z++) {
dotProduct += this.a.values[row][z] * this.b.values[z][c];
this.out.values[row][c] = dotProduct;
return null;
public static void main(String[] args) throws InterruptedException, ExecutionException {
int size = 100;
Matrix a = new Matrix(size, size);
a.randomize();
Matrix b = new Matrix(size, size);
b.randomize();
System.out.println("Warmup");
for (int t = 0; t < 1000; t++) {
Matrix c = a.ptimes(b);
Matrix d = a.times(b);
assert (c.equals(d));
System.out.println("Single Threaded");
for (int t = 0; t < 10; t++) {
long start = System.nanoTime();
Matrix d = a.times(b);
long finish = System.nanoTime();
System.out.println((finish - start)/1000000.0 + " milliseconds");
System.out.println("Multi Threaded with " + Runtime.getRuntime().availableProcessors() + " threads");
for (int t = 0; t < 10; t++) {
long start = System.nanoTime();
Matrix c = a.ptimes(b);
long finish = System.nanoTime();
System.out.println((finish - start)/1000000.0 + " milliseconds");
Matrix d = a.times(b);
assert (c.equals(d));
System.exit(0);
} -
Static methods in multi-thread environment.
Sorry for this silly question, but I have no clue...
If you're using classes with static methods in a application server environment, would that imply all threads use that same 'one in the jvm' method and would there be a possibility for performance loss?
Is calling another static method from a static method a good idea in a multi-thread environment, with respect to performance? Somehow I seem to get this java.lang.NoClassDefFoundError. Any ideas? The classes are in the same package. I only get these kind of problems calling static methods from static methods in a multi-thread environmnent. The static methods are pure utility functions and of course do not use class state.
Thanks for your help.Sorry for this question, wasn't thinking straight. I have the answer, won't post question on multiple forums.
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Multi-threaded performance server using 2 ports to two-way communication
Hi, I'm new in the forums so welcome everyone. I'm developing now an online computer game based on orginal Polish board-game, but it doesn't mean. Important is that I need to develope a high-performance multi-threaded server, which can serve... let's say few hundres of games, and a thousend of players simulateously. My server works on two ports/sockets.
First one is represented by "ServerSocketChannel clientConSsc" in my code. The main thread in my server class which invokes the method "run()" (which You can see below), registers clientConSsc with Selector and then repeatingly accepts incoming connections from clients on this socket. When connection(channel) is estabilished and clients wants to write some request to this channel, the main thread on server creates a new instance of class "RequestHandler" which extends Thread and handles this request (reads the request from channel, makes some changes on server, spreads some new messages to other clients in the same game and so on... everything on the same socket/port/channel). Then the channel/connection is closed by the server - I call such connections: "a short connections". In the same time the main thread continues the loop and is still able to accept connections from another players. That's the idea of multi-threaded server, right? :) And to this point, everything works fine, but... what if the server wants to trigger some new command, write new information to client?
Server could have tried to open a SocketChannel to client's IP address, but then the client programme would have to create and ServerSocketChannel object, bind it to some InetAddress and then... and then client becomes a server! - that breaks the idea of client-server cooperation and demands on players of my game to have routed some port on their machines. To resolve this problem I made some sort of "system" which, when some player/client is logging into my server, accepts second (this time constant, not "short") connection on the second port I mentoined on the beginning. This connection is held in variable "SocketChannel serverCon" of class "Player" - which reflects a player logged onto server. Server maintains every such connection till the client logs off. After the connection is accepted, the player whom connection it was is added to collection called "playersToRegisterToWrite". After the Selector.selectNow() is invoked (as You can see in the code below), each and every player's connection is registered in selector (with selection key - OP_WRITE and attachment pointing on owning player). In the same time client's code is trying to read some bytes from this connection and blocks on it until some bytes are written to this connection. When server wants to "tell" something to client, deliver some message/command, it creates a new instance of class which extends an abstract class called "ServerAction" (another new thread) and adds it to collection "actionsToDo". In ServerAction's method "run()" there are whole code to interact with client (e.g. send an update of players' list, an update of games' list, a chat message). Finnaly when Selector informs the server that some connection is writable (some client is waiting for commands), then server checks if there's any "actionToDo" involving this client/player. If there is, it unregisters the connection from Selector (so no other ServerAction (thread) can write on this connection) and starts the action. At the end of every "run()" method of subclass of ServerAction there's a code, which again adds the player to collection "playersToRegisterToWrite", so the player's connection can again be registered in Selector and the player can again receive informations from server - after it consumed THIS "ServerAction".
It looks to me like it should be working fine, but it's not. When I test my server and clients on the same machine (no ping/latency) everything seems to be working fine. But when it comes to play my game with somebody even on LAN or through the Internet there comes the problems. My first socket I describe (and first type of connections - short connections) works perfectly fine, so the requests triggered by client are delivered and handled properly. But the second socket is cirppling. For example: the server triggers a command refering to an update of clients logged to server' list. It is triggered by Selector so the client should be ready to read data from server, so the server sends data! And the client never receives it... Why?
It experimented a whole lot of time on SocketChannel's method "configureBlocking(boolean)", but it never helps. I think the client should always block it's listening thread on connection, contratry to server which is ment to be fast, so it should send the data through non-blocking channels. Am I right? Are there any rules refering blocking configuration of SocketChannels?
I will be grateful for every answer. To help You out I attach also drafts from run()'s methods of my classes.
Server's main method - main thread :
public void run() {
try {
selector = Selector.open();
clientConSsc.configureBlocking(false);
clientConSsc.register(selector , SelectionKey.OP_ACCEPT);
while(serverRunning) {
try {
selector.selectNow();
Iterator it;
synchronized(playersToRegisterToWrite) {
it = playersToRegisterToWrite.iterator();
while(it.hasNext()) {
Player player = (Player)it.next();
it.remove();
player.serverCon.configureBlocking(false);
player.serverCon.register(selector , SelectionKey.OP_WRITE , player);
Set keys = selector.selectedKeys() {
it = keys.iterator();
while(it.hasNext()) {
SelectionKey key = (SelectionKey)it.next();
if(key.isAcceptable()) {
it.remove();
clientCon = clientConSsc.accept();
clientCon.configureBlocking(false);
clientCon.register(selector , SelectionKey.OP_READ);
continue;
if(key.isReadable()) {
it.remove();
key.cancel();
new RequestHandler(this , (SocketChannel)key.channel()).start();
continue;
if(key.isWritable()) {
if(key.attachment() != null ) {
ServerAction action = null;
synchronized(actionsToDo) {
Iterator aIt = actionsToDo.iterator();
while(aIt.hasNext()) {
ServerAction temp = (ServerAction)aIt.next();
if(temp.getPlayer().equals((Player)key.attachment())) {
action = temp;
aIt.remove();
break;
if(action != null) {
key.channel().configureBlocking(false);
it.remove();
key.cancel();
action.start();
continue;
} catch(Exception e) {
statusArea.append(e.toString() + "\n");
e.printStackTrace();
continue;
} catch(ClosedChannelException e) {
statusArea.append(e.toString() + "\n");
} catch(IOException e) {
statusArea.append(e.toString() + "\n");
A part of server's RequestHandler's class' method run() - the method which handles requests triggered by client on first port:
public void run() {
boolean served = false;
try {
channel.configureBlocking(true);
retryCount++;
retry = false;
String command = ns.readText(channel).trim();
ns.statusArea.append("ktos przesyla komende: " + command + "\n");
if(command != null && !command.equals("ERROR")) {
String[] cmd = command.split("�");
ns.statusArea.append("komenda: " + cmd[0] + "\n");
if(cmd[0].equals("CHAT")) {
if(cmd.length != 5) {
retry();
} else {
if(cmd[2].equals("NOGAME")) { // jezeli nie ma okreslonej gry czyli rozsylamy do wszystkich
for(int i = 0 ; i < ns.loggedPlayersListItems.size() ; i++) {
Player current = (Player)ns.loggedPlayersListItems.get(i);
if(current.state == Player.CHOOSING && !current.equals(new Player(Integer.parseInt(cmd[1])))) // jezeli gracz jest w okienku wybierania gry to wysylamy mu broadcast
ns.actionsToDo.add(new SendMsg(ns , current , "CHAT�" + cmd[1] + "�" + cmd[3] + "�" + cmd[4]));
} else {
Game game = (Game)ns.gamesListItems.get(ns.gamesListItems.indexOf(new Game(Integer.parseInt(cmd[2]))));
for(int i = 0 ; i < game.players.size() ; i++) {
Player current = (Player)game.players.get(i);
if(!current.equals(new Player(Integer.parseInt(cmd[1]))))
ns.actionsToDo.add(new SendMsg(ns , current , "CHAT�" + cmd[1] + "�" + cmd[3] + "�" + cmd[4]));
served = true;
} else if(cmd[0].equals("GETGAMEINFO")) {
if(cmd.length != 3)
retry();
else {
int gameID = Integer.parseInt(cmd[2]);
ns.statusArea.append("poproszono o informacje o grze nr: " + gameID + "\n");
Game checkedGame = new Game(gameID);
if(ns.gamesListItems.contains(checkedGame)) {
Game game = (Game)ns.gamesListItems.get(ns.gamesListItems.indexOf(checkedGame));
channel.configureBlocking(true);
ObjectOutputStream oos = new ObjectOutputStream(channel.socket().getOutputStream());
oos.writeObject(game);
oos.writeObject(game.players);
oos.flush();
ns.statusArea.append("wyslano informacje o grze nr: " + gameID + "\n");
} else {
ns.statusArea.append("brak gry o nr: " + gameID + "\n");
served = true;
} catch(IOException e) {
e.printStackTrace();
if(!served) {
ns.findAndDisconnectPlayer(channel);
try {
channel.close();
} catch(IOException e) {
e.printStackTrace();
}An example of ServerAction's subclass - the class which triggers server commands to client on second port:
class UpdateLoggedPlayersList extends ServerAction {
public UpdateLoggedPlayersList(NeuroServer ns , Player player) {
super(ns , player);
public void run() {
try {
serverCon.configureBlocking(true);
ns.sendText("UPDATELOGGEDPLAYERSLIST" , serverCon);
if(ns.readText(serverCon).equals("OK")) {
ObjectOutputStream oos = new ObjectOutputStream(serverCon.socket().getOutputStream());
oos.writeObject(ns.loggedPlayersListItems);
oos.flush();
synchronized(ns.playersToRegisterToWrite) {
ns.playersToRegisterToWrite.add(player);
} catch(IOException e) {
e.printStackTrace();
}A part of client's CmdHandler's class' method run() - the method which handles commands triggered by server:
public void run() {
try {
while(works) {
String command = nc.readText(nc.serverCon);
System.out.println("Server przesyla komende: " + command + "\n");
String[] cmd = command.split("�");
if(cmd[0] != null && !cmd[0].equals("ERROR")) {
if(cmd[0].equals("CHAT")) {
if(nc.chooseGameDialog != null && nc.chooseGameDialog.isVisible()) { // jezeli na wybieraniu gry
newChatEntry(cmd[2] , null , cmd[3] , nc.chooseGameDialog.chatPane);
} else if(nc.readyDialog != null && nc.readyDialog.isVisible()) { // jesli na przygotowywaniu
Player sender = (Player)nc.actGame.players.get(nc.actGame.players.indexOf(new Player(Integer.parseInt(cmd[1]))));
newChatEntry(cmd[2] , sender.fraction , cmd[3] , nc.readyDialog.chatPane);
} else if(nc.ng != null) { // jesli w grze
Player sender = (Player)nc.actGame.players.get(nc.actGame.players.indexOf(new Player(Integer.parseInt(cmd[1]))));
newChatEntry(cmd[2] , sender.fraction , cmd[3] , nc.ng.inGameChatPane);
} else if(cmd[0].equals("UPDATELOGGEDPLAYERSLIST")) {
nc.sendText("OK" , nc.serverCon , false);
nc.serverCon.configureBlocking(true);
ObjectInputStream ois = new ObjectInputStream(nc.serverCon.socket().getInputStream());
DefaultListModel players = (DefaultListModel)ois.readObject();
nc.chooseGameDialog.updateLoggedPlayersList(players);
} catch(IndexOutOfBoundsException e) {
System.out.println(e);
} catch(IOException e) {
System.out.println(e);
} catch(ClassNotFoundException e) {
System.out.println(e);
}And two methods I used in codes above: sendText(String text , SocketChannel sc) and readText(SocketChannel sc) - they are my "utility" methods, which I use to send and receive Strings through specified SocketChannels.
boolean sendText(String text , SocketChannel sc) {
ByteBuffer bbuf = ByteBuffer.allocate(BSIZE);
boolean sendRetry;
boolean sent = false;
do {
sendRetry = false;
try {
StringBuffer cmd = new StringBuffer();
cmd.setLength(0);
if(text.length()+4 < 100)
cmd.append("0");
if(text.length()+4 < 10)
cmd.append("0");
cmd.append(Integer.toString(text.length()+4) + "�");
cmd.append(text);
cmd.append("\n");
bbuf = charset.encode(CharBuffer.wrap(cmd));
sc.write(bbuf);
bbuf.clear();
int n = sc.read(bbuf);
if(n == 1) {
bbuf.flip();
Byte re = bbuf.get();
if(re == 1) {
sendRetry = true;
} else {
sent = true;
} catch(Exception e) {
findAndDisconnectPlayer(sc);
try {
sc.close();
} catch(IOException f) {
f.printStackTrace();
return false;
} while(!sent && sendRetry);
return true;
String readText(SocketChannel sc) {
ByteBuffer bbuf = ByteBuffer.allocate(BSIZE);
int readRetryCount = -1;
boolean readRetry;
do {
readRetry = false;
readRetryCount++;
StringBuffer cmd = new StringBuffer();
cmd.setLength(0);
bbuf.clear();
try {
readLoop:
while(true) {
int n = sc.read(bbuf);
if(n > 0) {
bbuf.flip();
CharBuffer cbuf = charset.decode(bbuf);
while(cbuf.hasRemaining()) {
char c = cbuf.get();
if(c == '\r' || c == '\n') break readLoop;
cmd.append(c);
} else break;
statusArea.append(Thread.currentThread().getId() + " readText() odczytuje: " + cmd.toString() + "\n");
if(cmd.length() < 3 || Integer.parseInt(cmd.substring(0 , 3)) != cmd.length()) {
sc.write(ByteBuffer.wrap(new byte[] {1}));
readRetry = true;
} else {
sc.write(ByteBuffer.wrap(new byte[] {0})); // length OK
return cmd.toString().substring(4 , cmd.toString().length());
} catch(Exception e) {
findAndDisconnectPlayer(sc);
try {
sc.close();
} catch(IOException f) {
f.printStackTrace();
return "ERROR";
} while(readRetry && readRetryCount < 3);
findAndDisconnectPlayer(sc);
try {
sc.close();
} catch(IOException e) {
e.printStackTrace();
return "ERROR";
}Edited by: Kakalec on Jul 23, 2008 11:04 AMYou seem to be using a horrendous mixture of PrintWriters, BufferedReaders, ObjectOutputStreams, and no doubt ObjectInputStreams. You can't do that.
Some rules about this:
(a) Whenever you use a stream or reader or writer on a socket, you must allocate it once for the life of the socket, not every time you want to do an I/O.
There are many reasons for this including losing buffered data in the old stream and auto-closure of the socket on garbage-collection of the old stream.
(b) You can't mix stream types on the same socket. (i) If you're writing objects, use an ObjectOutputStream, you must read with an ObjectInputStream, and you can't read or write anything that isn't supported by the API of ObjectOutputStream. (ii) If you're writing lines, use a BufferedWriter and a BufferedReader at the other end. If you're writing characters, use a Writer and a Reader. (iii) If you're writing primitive data or UTF strings, use a DataOutputStream and a DataInputStream. (iv) If you're writing bytes, use DataOutputStream and a DataInputStream or an OutputStream and an InputStream. You can't mix (i), (ii), (iii), and (iv).
(c) Don't use PrintWriter or PrintStream over the network. They swallow exceptions that you need to know about. They are for writing to the console, or log files, where you don't really care about exceptions.
(d) Call flush() before reading.
(e) Always close the 'outermost' output stream or writer of a socket, never the input stream or the socket itself. Closing any of these closes the socket and therefore makes the other stream unusable, but only closing the output stream/writer will flush it. -
Multi-thread application recompile object with make but runs with old value
Hi. I am working on a simulation in Java, and there is some behavior going on that I cannot understand. Granted, I'm a mechanical engineer, not a CS student (a fact that is probably made obvious by the code I'm posting below). The simulation comprises three parts: a controller, a robot, and a 3-d sensor. Here's the code for the "Simulation" application.
class Simulation {
void go() {
ThreeDSensor sensorRunner = new ThreeDSensor();
VSController controllerRunner = new VSController();
KukaKR15SL robotRunner = new KukaKR15SL();
Thread sensorThread = new Thread(sensorRunner);
Thread controllerThread = new Thread(controllerRunner);
Thread robotThread = new Thread(robotRunner);
sensorThread.start();
try {
Thread.sleep(1000); // Give sensorThread time to start in order to catch first triggers
} catch(InterruptedException ex) {
ex.printStackTrace();
controllerThread.start();
try {
Thread.sleep(1000); // Give controllerThread time to open the socket for communication with robotThread
} catch(InterruptedException ex) {
ex.printStackTrace();
robotThread.start();
public static void main(String[] args) {
Simulation sim = new Simulation();
sim.go();
}I guess the big reason I'm using multi-threading is that once this simulation is working I want to be able to just run VSController alone and have it interface with a robot controller and a PC performing image processing. So with multiple threads I'm sending TCP and UDP messages around just like the final system will.
I have made an object for my VSController that just stores values used by the simulation. That way I could have them all in one place instead of hunting through methods to change them. One example is "double noiseThreshold". Quickly, here is the code for "ControllerSettings.java".
class ControllerSettings {
final double cameraXOffset = 0; // If > 0 then the origin of the camera CS is not on the center line of the lens
final double cameraYOffset = 0; // If > 0 then the origin of the camera CS is not on the center line of the lens
final double cameraZOffset = 700; // The distance that must be kept between the camera and the target
// Error magnitude less than this is disregarded (in centimeters if roundingData else in millimeters)
final double noiseThreshold = 60;
final boolean estimatingEndPoints = false; // If the controller is using two images per cycle then true
final boolean roundingData = false;
final boolean using3DData = true; // How double[] sent from Matlab image processing is used
* If the robot controller uses the output of this controller to command
* motions in cartesian space then true. This is used in two places: 1) initial guess of Jacobian,
* and 2) "commandType" element sent to robot controller.
final boolean useRobotControllerModel = false;
final double thetaBumpValueForEstimationOfJacobian = .1; // Distance each joint is jogged in estimation process
final double bumpDistance = 50; // Distance robot moves each time (magnitude of translation in mm)
final double limitAngular = .5; // Max amout robot joint will be commanded to rotate (in degrees)
}And here is some pertinent code from "VSController.java".
class VSController implements Runnable{
ControllerSettings cSettings; // Stores all the preferences used by the controller
NGN controller; // This is the controller algorithm.
int dof; // The degrees of freedom of the robot being controlled
KukaSendData ksd; // This provides communication to the robot.
protected DatagramSocket socketForVisionSystem = null;
ImageFeaturesData ifd; // This parses and stores data from the image system.
double[] errorVector; // This is what's acted on by the algorithm
PrintWriter errorTrackerOut = null; // For analysis of error vector
public void run() {
VSController vsc = new VSController();
vsc.go();
public void go() {
initWriters();
cSettings = new ControllerSettings();
public boolean isNoise() {
boolean ret = false;
double magnitude = 0;
for (int i = 0; i < errorVector.length; i++) {
magnitude += errorVector[i] * errorVector;
magnitude = Math.sqrt(magnitude);
if (magnitude <= cSettings.noiseThreshold) {
System.out.println("VSController: magnitude (of errorVector) = " + magnitude +
", threshold = " + cSettings.noiseThreshold); // Debug
Now here's my issue: I change the value for "noiseThreshold" in "ControllerSettings.java" then run make from terminal (makefile code posted below) and rerun "Simulation". However, despite my changes to "ControllerSettings.java" the value for "noiseThreshold" is not changed, as evidenced by the output on the terminal screen:VSController: magnitude (of errorVector) = 6.085046125925263, threshold = 10.0 See, that value of 10.0 is what I used to have for noiseThreshold. I do not know why this value does not update even though I save the java file and execute make in between executions of Simulation. I would love it if someone could explain this problem to me.
Here's the contents of makefile.
JFLAGS = -cp ../Jama\-1\.0\.2.jar:../utils/:/usr/share/java/vecmath\-1\.5\.2.jar:.
JC = javac
.SUFFIXES: .java .class
.java.class:
$(JC) $(JFLAGS) $*.java
CLASSES = \
ControllerSettings.java \
ImageFeaturesData.java \
KukaKR15SL.java \
../utils/KukaSendData.java \
NGN.java \
Puma560.java \
Robot.java \
RobotSettings.java \
Simulation.java \
SimulationSettings.java \
SixRRobot.java \
Targets.java \
TargetsSettings.java \
ThreeDData.java \
ThreeDSensor.java \
VSController.java
default: classes
classes: $(CLASSES:.java=.class)
clean:
$(RM) *.classEdited by: raequin on Apr 5, 2010 1:43 PMI saw this explanation about what's causing my problem.
"When the Java compiler sees a reference to a final static primitive or String, it inserts the actual value of that constant into the class that uses it. If you then change the constant value in the defining class but don't recompile the using class, it will continue to use the old value."
I verified that the value updates if I also change something in VSController.java, forcing it to recompile. I think I will solve this problem by just making the variables in ControllerSettings no longer final (and then recompile VSController to make sure it takes effect!). Is there another solution? I saw intern(), but that seems to only apply to Strings.
Thanks. -
Hi,
I've got a tricky question: I have to read large files (over 150 MB) - I found here several topics about reading such a large files, but all examples were about single-threaded reading from file... Do you think, multi-threaded reading would be faster? I am in quite a dilemma: multiple threads in general means faster processing, but in this case, all threads are reading from the same source/file
(I use javax.mail.util.SharedFileInputStream for multi-threaded file reading - each stream in separated thread)
so what do you think, which is faster: single-thread or multiple-thread? and if so, how many threads would be fine - 2, 3 or 4?
thanks a lotkvasoo wrote:
Herko_ter_Horst wrote:
The I/O thread processing thread(s) approach will work when the processing takes more time than the I/O (i.e. when the medium can transfer information faster than a single thread can process it).it is very likely that processing will take more time then file reading - there will be 5-7 regex to match per line, sometimes object creation and filling object fith some data
so it seems to be just like I wrote some posts before: while one thread is reading data from file, another could process already read data - I am just considering malcolmmc's idea of blocking queue - one thread to perform I/O operations and one thread to process data - these threads would be connected through blocking queue....hmm that sounds good to me.. thanks malcolmmc
thank you guys for your help & suggestions and if you still have something to advise me, I will be thankfulSeparation of concerns, dude. Read the raw data in, in one thread, and split out the processing to multiple threads. I really advise you take the time to actually measure the performance of the multi-threaded processing vs the single-threaded one though. I mean, really do actually do that. Don't just assume - as so many people do - that throwing more threads at every problem will always speed it up, because it's so often not the case. -
In order to bench my database i made an application that just call some procedures (rselect only no update or insert).
The application instanciate 15 threads, each with a connection to my database.
My problem is that it seems that my calls are serialiazed and take a lot of time to answer.
But if I launch multiple instances of my application ( each with only 1 thread) I don't have this problem.
How can I avoid this problem ?
Thanks, bernardHere's the test code I've been using for ad-hoc multi-threaded testing; it's a bit sloppy, but it works and I no longer have time to finish the project up right and pretty. At the risk of derision from the better Java programmers here, I post it and hereby dedicate this mess to the public domain. Enjoy...
3 Java files.
File 1:
import java.util.ArrayList;
public class DBTest {
public static void main (String args[]) {
TestHarness testSuite1;
ArrayList testSet1 = new ArrayList();
for ( int i=0; i< 2; i++) {
testSet1.add(new Check1(2) );
testSuite1 = new TestHarness (testSet1);
testSuite1.go();
testSuite1.report(System.out);
class Check1 extends Thread {
private long runLength;
private int myThreadNumber;
private static int threadNumber = 0;
private static Object lockObj = new Object();
public Check1 (int _runLength) {
runLength = _runLength;
synchronized(lockObj) {
myThreadNumber = threadNumber++;
public Check1 () {
this(10);
public void run () {
try {
BusyDB workload = new BusyDB();
workload.beBusy (runLength, myThreadNumber);
catch (InterruptedException e) {
System.err.println("Interrupted !");
catch (Exception e) {
e.printStackTrace(System.err);
public String toString() {
return "thread " + myThreadNumber + ": iterated for " + runLength + " iterations\n";
}File 2:
import java.sql.*;
public class BusyDB
private static long iterModulus = 1000;
public void beBusy(long iterations, int threadID)
throws Exception
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con = null;
PreparedStatement ps1;
ResultSet rs1;
int i = 0;
try {
while ( i < iterations )
con = DriverManager.getConnection("jdbc:oracle:thin:user/password@db_host:1521:db_sid");
con.setAutoCommit(false);
ps1 = con.prepareStatement("select sysdate from dual");
rs1 = ps1.executeQuery();
i++;
if (i % iterModulus == 0)
System.out.println("Thread number " + threadID +": " + iterModulus
+ " more iterations " + i + " total iterations");
con.commit();
rs1.close();
if( con != null ) con.close();
catch (Exception e)
e.printStackTrace(System.out);
i = i + 1;
} finally {
if( con != null ) con.close();
}File 3:
import java.io.PrintStream;
import java.util.Collection;
import java.util.Iterator;
public class TestHarness
private Collection subTests;
private boolean wasInterrupted = false;
private final long created = System.currentTimeMillis();
private long start, end;
private String testSuiteName;
public TestHarness ( Collection subTests ) {
this.subTests = subTests;
this.testSuiteName = "anonymous";
public void go () {
start = System.currentTimeMillis();
System.out.println("Test suite " + testSuiteName + " started: " + start);
Iterator i = subTests.iterator();
while (i.hasNext() ) ((Thread)i.next() ).start();
System.out.println("All subtests finished starting at: " + System.currentTimeMillis() );
i = subTests.iterator();
try {
while (i.hasNext() ) {
((Thread)i.next() ).join();
catch (InterruptedException e) {
wasInterrupted = true;
end = System.currentTimeMillis();
System.out.println("All subtests finished running at: " + end );
public void report( PrintStream out) {
out.println ("\nTest Suite: " + testSuiteName);
out.println ("Runtime millis: " + (end - start) );
Iterator i = subTests.iterator();
while (i.hasNext() ) out.print( i.next().toString() );
if (wasInterrupted) {
out.println("======== ERROR ========");
out.println("Test thread interrupted");
} -
Hi I'm writing a program like Multi-tap (the text entry before T9 introduced) on mobilephone.
I'm having problem with some of the KEYs. They do not work properly.
As indicated in the code
HERE HERE [3] suppose to function as space button....However whenever the key is pressed before the 'time out' (I use sceduler to implement the time out) it will print half of the previous character instead of space. this key is not related to the scheduler. so i suspect it is something related to multi-thread programming.
HERE HERE [1] function as the caps lock. it can even show the indicator properly.... so i need to settle this b4 i continue.
HEREHERE [2] function as clear button. it doest work too
Someone please help me....
* To change this template, choose Tools | Templates
* and open the template in the editor.
package textEntry;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.*;
import java.util.*;
* @author Ed's
public class MyCanvas extends GameCanvas {
public static final String[] keys =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","abc", "def", "ghi", "jkl",
"mno", "pqrs", "tuv", "wxyz"};
public static final String[] capitalKey =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","ABC", "DEF", "GHI", "JKL",
"MNO", "PQRS", "TUV", "WXYZ"};
StringBuffer width = new StringBuffer();
Timer keyTimer;
textEntryMain main;
public static char ch;
public boolean keypress=false;
public boolean capital;
public boolean diffrentKey;
String currentIndicator="abc";
int countPress=0;
//int previndex=0;
public int counter=-1;
int index=-1;
int print=0;
int white_space=6;
public StringBuffer sms;
int baseline=10;
int y_axis=12;
int line=1;
char last;
boolean dontPrint=true; //dont print if timer printed or it is at begining
Font font;
Graphics g;
public long time;
int poundHit=0;
String justPressed;
String prevPressed=null;
char prevChar;
//Sms class
Form smsfrm;
TextField smsField ;
//Char Selection speed
public boolean first;
int selection_speed=1500;
//font color (blue)
public int red=0,green=0,blue=255;
//Background color (white)
public int back_red=250,back_green=250,back_blue=250;
Form menu;
public MyCanvas(textEntryMain main){
super(false);
first=true;
this.main=main;
sms=new StringBuffer();
g=getGraphics();
font=Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);
keyTimer = new Timer ();
keyTimer.schedule (new task (this), selection_speed, selection_speed);
drawIndicator(currentIndicator);
public void drawIndicator(String indicator){
Font f = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_ITALIC, Font.SIZE_SMALL);
Graphics g = getGraphics();
g.setFont(f);
int x= getWidth()-20;
g.setColor(back_red,back_green,back_blue);
g.fillRect(x,2,15,10);
g.setColor(20,20,20);
g.drawString(indicator, x, 2, g.TOP|g.LEFT);
public void callPaint(char ch){
drawIndicator(currentIndicator);
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
if(first){
g.fillRect(0,0,getWidth(),getHeight());
reset();
redrawAll();
first=false;
//baseline -1 so that i can cover the pointer
g.fillRect(baseline-1,y_axis,font.charWidth(this.last)+3,font.getHeight());
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
flushGraphics();
public void showPointer(){
Graphics g = getGraphics();
g.setColor(0,0,0);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//pointer appear //pointer disappear-use white line so that it cover the pointer line
public void hidePointer(){
Graphics g = getGraphics();
g.setColor(back_red,back_green,back_blue);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//draw the selected
public void ConfirmPaint(char ch){
Graphics g = getGraphics();
sms.append(ch);
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE); //draw the selected
baseline+=font.charWidth(ch); // so that the nect letter won't be drawn on the same position
if(baseline>getWidth()-30){ //move to the next line
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public synchronized void deleteChar(){
if(sms.charAt(sms.length()-1)==' '){
baseline-=white_space;
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
else{
baseline-=font.charWidth(sms.charAt(sms.length()-1));
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
flushGraphics();
public void redraw(char ch ){
Graphics g= getGraphics();
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
baseline+=font.charWidth(ch);
if(baseline>getWidth()-30){
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public void reset(){
if(width.length() >0)
width.delete(0,width.length()-1);
line=1;
baseline=10;y_axis=12;
public void redrawAll(){
Graphics g=getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(0,0,getWidth(),getHeight());
reset();
for(int a=0;a<sms.length();a++)
redraw(sms.charAt(a));
/*public synchronized void keyRepeated (int keyCode) {
int one=1;
/* if(keyCode != KEY_POUND && keyCode != KEY_STAR){
ConfirmPaint((char)keyCode);
if (keyCode == 1){
ConfirmPaint((char)one);
public synchronized void keyPressed (int keyCode) {
justPressed=getKeyName(keyCode);
time=System.currentTimeMillis(); // record the time when the keypress is pressed
if(justPressed.equals("NUM0")){ //caps lock show indicator .............HERE HERE HERE HERE [1]
if(poundHit == 0){
currentIndicator="ABC";
poundHit++;
drawIndicator(currentIndicator);
//set the string buffer to another one
if(poundHit == 1){
currentIndicator="123";
poundHit++;
drawIndicator(currentIndicator);
if(poundHit == 2){
currentIndicator="abc";
poundHit=0;
drawIndicator(currentIndicator);
if(justPressed.equalsIgnoreCase("SEND")){ //send button allocated as clear button ................. HERE HERE HERE [2]
if(sms.length()>0){
hidePointer();
if(baseline<=10){
System.out.println(baseline);
line-=2;
baseline=(int)width.charAt(line);
line++;
y_axis-=24;
deleteChar();
if(justPressed.equals("STAR")){//space ........................................ HERE HERE HERE HERE HERE [3]
hidePointer();
sms.append(" ");
baseline+=white_space;
showPointer();
prevPressed=justPressed;
else{
if(justPressed.equals("NUM1")){index=0;}
if(justPressed.equals("NUM2")){index=1;}
if(justPressed.equals("NUM3")){index=2;}
if(justPressed.equals("NUM4")){index=3;}
if(justPressed.equals("NUM5")){index=4;}
if(justPressed.equals("NUM6")){index=5;}
if(justPressed.equals("NUM7")){index=6;}
if(justPressed.equals("NUM8")){index=7;}
if(justPressed.equals("NUM9")){index=8;}
if(index==0){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=35;}
if(countPress<34){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated (prev!=)
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==1 || index==2 || index == 3 || index == 4
|| index ==5 || index==7){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=4;}
if(countPress<3){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint = false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==6 || index==8){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed)|| dontPrint){
if(dontPrint){countPress=5;}
if(countPress<4){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
/////////////task class for schedule on constructor
class task extends TimerTask {
public static boolean bool;
MyCanvas canvas;
public task (MyCanvas canvas) {
this.canvas=canvas;
public void run () {
if(canvas.keypress){
if(System.currentTimeMillis()-canvas.time>150){ //compare the time with the time out
canvas.ConfirmPaint(MyCanvas.ch);
canvas.counter=-1;
canvas.keypress=false;
canvas.dontPrint=true;
canvas.showPointer();
}Hi I'm writing a program like Multi-tap (the text entry before T9 introduced) on mobilephone.
I'm having problem with some of the KEYs. They do not work properly.
As indicated in the code
HERE HERE [3] suppose to function as space button....However whenever the key is pressed before the 'time out' (I use sceduler to implement the time out) it will print half of the previous character instead of space. this key is not related to the scheduler. so i suspect it is something related to multi-thread programming.
HERE HERE [1] function as the caps lock. it can even show the indicator properly.... so i need to settle this b4 i continue.
HEREHERE [2] function as clear button. it doest work too
Someone please help me....
* To change this template, choose Tools | Templates
* and open the template in the editor.
package textEntry;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.*;
import java.util.*;
* @author Ed's
public class MyCanvas extends GameCanvas {
public static final String[] keys =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","abc", "def", "ghi", "jkl",
"mno", "pqrs", "tuv", "wxyz"};
public static final String[] capitalKey =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","ABC", "DEF", "GHI", "JKL",
"MNO", "PQRS", "TUV", "WXYZ"};
StringBuffer width = new StringBuffer();
Timer keyTimer;
textEntryMain main;
public static char ch;
public boolean keypress=false;
public boolean capital;
public boolean diffrentKey;
String currentIndicator="abc";
int countPress=0;
//int previndex=0;
public int counter=-1;
int index=-1;
int print=0;
int white_space=6;
public StringBuffer sms;
int baseline=10;
int y_axis=12;
int line=1;
char last;
boolean dontPrint=true; //dont print if timer printed or it is at begining
Font font;
Graphics g;
public long time;
int poundHit=0;
String justPressed;
String prevPressed=null;
char prevChar;
//Sms class
Form smsfrm;
TextField smsField ;
//Char Selection speed
public boolean first;
int selection_speed=1500;
//font color (blue)
public int red=0,green=0,blue=255;
//Background color (white)
public int back_red=250,back_green=250,back_blue=250;
Form menu;
public MyCanvas(textEntryMain main){
super(false);
first=true;
this.main=main;
sms=new StringBuffer();
g=getGraphics();
font=Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);
keyTimer = new Timer ();
keyTimer.schedule (new task (this), selection_speed, selection_speed);
drawIndicator(currentIndicator);
public void drawIndicator(String indicator){
Font f = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_ITALIC, Font.SIZE_SMALL);
Graphics g = getGraphics();
g.setFont(f);
int x= getWidth()-20;
g.setColor(back_red,back_green,back_blue);
g.fillRect(x,2,15,10);
g.setColor(20,20,20);
g.drawString(indicator, x, 2, g.TOP|g.LEFT);
public void callPaint(char ch){
drawIndicator(currentIndicator);
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
if(first){
g.fillRect(0,0,getWidth(),getHeight());
reset();
redrawAll();
first=false;
//baseline -1 so that i can cover the pointer
g.fillRect(baseline-1,y_axis,font.charWidth(this.last)+3,font.getHeight());
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
flushGraphics();
public void showPointer(){
Graphics g = getGraphics();
g.setColor(0,0,0);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//pointer appear //pointer disappear-use white line so that it cover the pointer line
public void hidePointer(){
Graphics g = getGraphics();
g.setColor(back_red,back_green,back_blue);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//draw the selected
public void ConfirmPaint(char ch){
Graphics g = getGraphics();
sms.append(ch);
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE); //draw the selected
baseline+=font.charWidth(ch); // so that the nect letter won't be drawn on the same position
if(baseline>getWidth()-30){ //move to the next line
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public synchronized void deleteChar(){
if(sms.charAt(sms.length()-1)==' '){
baseline-=white_space;
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
else{
baseline-=font.charWidth(sms.charAt(sms.length()-1));
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
flushGraphics();
public void redraw(char ch ){
Graphics g= getGraphics();
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
baseline+=font.charWidth(ch);
if(baseline>getWidth()-30){
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public void reset(){
if(width.length() >0)
width.delete(0,width.length()-1);
line=1;
baseline=10;y_axis=12;
public void redrawAll(){
Graphics g=getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(0,0,getWidth(),getHeight());
reset();
for(int a=0;a<sms.length();a++)
redraw(sms.charAt(a));
/*public synchronized void keyRepeated (int keyCode) {
int one=1;
/* if(keyCode != KEY_POUND && keyCode != KEY_STAR){
ConfirmPaint((char)keyCode);
if (keyCode == 1){
ConfirmPaint((char)one);
public synchronized void keyPressed (int keyCode) {
justPressed=getKeyName(keyCode);
time=System.currentTimeMillis(); // record the time when the keypress is pressed
if(justPressed.equals("NUM0")){ //caps lock show indicator .............HERE HERE HERE HERE [1]
if(poundHit == 0){
currentIndicator="ABC";
poundHit++;
drawIndicator(currentIndicator);
//set the string buffer to another one
if(poundHit == 1){
currentIndicator="123";
poundHit++;
drawIndicator(currentIndicator);
if(poundHit == 2){
currentIndicator="abc";
poundHit=0;
drawIndicator(currentIndicator);
if(justPressed.equalsIgnoreCase("SEND")){ //send button allocated as clear button ................. HERE HERE HERE [2]
if(sms.length()>0){
hidePointer();
if(baseline<=10){
System.out.println(baseline);
line-=2;
baseline=(int)width.charAt(line);
line++;
y_axis-=24;
deleteChar();
if(justPressed.equals("STAR")){//space ........................................ HERE HERE HERE HERE HERE [3]
hidePointer();
sms.append(" ");
baseline+=white_space;
showPointer();
prevPressed=justPressed;
else{
if(justPressed.equals("NUM1")){index=0;}
if(justPressed.equals("NUM2")){index=1;}
if(justPressed.equals("NUM3")){index=2;}
if(justPressed.equals("NUM4")){index=3;}
if(justPressed.equals("NUM5")){index=4;}
if(justPressed.equals("NUM6")){index=5;}
if(justPressed.equals("NUM7")){index=6;}
if(justPressed.equals("NUM8")){index=7;}
if(justPressed.equals("NUM9")){index=8;}
if(index==0){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=35;}
if(countPress<34){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated (prev!=)
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==1 || index==2 || index == 3 || index == 4
|| index ==5 || index==7){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=4;}
if(countPress<3){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint = false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==6 || index==8){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed)|| dontPrint){
if(dontPrint){countPress=5;}
if(countPress<4){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
/////////////task class for schedule on constructor
class task extends TimerTask {
public static boolean bool;
MyCanvas canvas;
public task (MyCanvas canvas) {
this.canvas=canvas;
public void run () {
if(canvas.keypress){
if(System.currentTimeMillis()-canvas.time>150){ //compare the time with the time out
canvas.ConfirmPaint(MyCanvas.ch);
canvas.counter=-1;
canvas.keypress=false;
canvas.dontPrint=true;
canvas.showPointer();
} -
How to use Multi Thread to make a animation
Hello
Currently i am writing a router simulator using Java SE 1.4.2. I am facing a problem that is I cannot use multithread to update my Jframe animation.
Here i give my approach.
My idea is I used a JPanel in JFrame and I used Graphics g draw all background in Jpanel and add it into Jframe. It works since there is no animation invovled. I want to do some animation based on this background which i draw. But all animation should be controled by other threads due to i want other threads can control all animation. But i hit a error which is nullpointexception. The reason looks like which i used another to do animation, it cannot find the reference which is point to the Jpanel and Jframe. May u teach me a correct way to do multi threads animation in Jframe? thanks.
all the best and regards!A simple annimation moving a circle round a screen. This uses a model that defines the dynamics of the annimation, a view to display a visual representation of the model and an event system (observer/observable) to notify the view that the model has changed.
I hope this helps.
import java.awt.*;
import javax.swing.*;
import java.util.*;
public class Test20041023 extends JFrame
public Test20041023()
super("Simple Annimation Demo");
AnnimationModel annimationModel = new AnnimationModel();
AnimationView animationView = new AnimationView(annimationModel);
setContentPane(animationView);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
private static class AnimationView extends JPanel
private static final int PREFERRED_WIDTH = 512;
private static final int PREFERRED_HEIGHT = 256;
AnimationView(AnnimationModel annimationModel)
// Save a reference to the model for use
// when the view is updated
annimationModel_ = annimationModel;
// Listen for the events indicating that the model has changed
annimationModel_.addObserver(new Observer()
public void update(Observable o, Object arg)
// All we need to do is to get the view to repaint
AnimationView.this.repaint();
public void paintComponent(Graphics g)
super.paintComponent(g);
// Update the view based on the information in the model.
g.setColor(Color.red);
// Convert the model positions to view positions
// in this case by scaling to the actual width and height.
int xScreenPosition = scaleValue(annimationModel_.getX(), getWidth() - 20 ) + 5;
int yScreenPosition = scaleValue(annimationModel_.getY(), getHeight() - 20 ) + 5;
// Display the position of the point
g.fillOval(xScreenPosition, yScreenPosition, 10, 10);
private int scaleValue(double v, double size)
return (int)((v+1.0)*0.5 * size + 0.5);
public Dimension getPreferredSize()
return new Dimension(PREFERRED_WIDTH, PREFERRED_HEIGHT);
// The saved reference to the model
private AnnimationModel annimationModel_;
private static class AnnimationModel extends Observable
AnnimationModel()
Thread annimationThread = new Thread()
public void run()
// Loop forever updating the model
// and notifying the observers.
while(true)
// Wait 0.05 seconds until the next frame update point
try
sleep(50L);
catch (InterruptedException e)
// Nothing to do
// Update the model - in this case it is very simple
theta_ += 0.1;
// Notify the observers
setChanged();
notifyObservers();
annimationThread.start();
// Model access methods
public double getX()
return Math.cos(theta_);
public double getY()
return Math.sin(theta_);
// The angular position of the point
private double theta_;
// Simple test main
static public void main(String[] args)
new Test20041023().setVisible(true);
} -
SSRS - Is there a multi thread safe way of displaying information from a DataSet in a Report Header?
In order to dynamically display data in the Report Header based in the current record of the Dataset, we started using Shared Variables, we initially used ReportItems!SomeTextbox.Value, but we noticed that when SomeTextbox was not rendered in the body
(usually because a comment section grow to occupy most of the page if not more than one page), then the ReportItem printed a blank/null value.
So, a method was defined in the Code section of the report that would set the value to the shared variable:
public shared Params as String
public shared Function SetValues(Param as String ) as String
Params = Param
Return Params
End Function
Which would be called in the detail section of the tablix, then in the header a textbox would hold the following expression:
=Code.Params
This worked beautifully since, it now didn't mattered that the body section didn't had the SetValues call, the variable persited and the Header displayed the correct value. Our problem now is that when the report is being called in different threads with
different data, the variable being shared/static gets modified by all the reports being run at the same time.
So far I've tried several things:
- The variables need to be shared, otherwise the value set in the Body can't be seen by the header.
- Using Hashtables behaves exactly like the ReportItem option.
- Using a C# DLL with non static variables to take care of this, didn't work because apparently when the DLL is being called by the Body generates a different instance of the DLL than when it's called from the header.
So is there a way to deal with this issue in a multi thread safe way?
Thanks in advance!
Hi Angel,
Per my understanding that you want to dynamic display the group data in the report header, you have set page break based on the group, so when click to the next page, the report hearder will change according to the value in the group, when you are using
the shared variables you got the multiple thread safe problem, right?
I have tested on my local environment and can reproduce the issue, according to the multiple safe problem the better way is to use the harshtable behaves in the custom code, you have mentioned that you have tryied touse the harshtable but finally got
the same result as using the ReportItem!TextBox.Value, the problem can be cuased by the logic of the code that not works fine.
Please reference to the custom code below which works fine and can get all the expect value display on every page:
Shared ht As System.Collections.Hashtable = New System.Collections.Hashtable
Public Function SetGroupHeader( ByVal group As Object _
,ByRef groupName As String _
,ByRef userID As String) As String
Dim key As String = groupName & userID
If Not group Is Nothing Then
Dim g As String = CType(group, String)
If Not (ht.ContainsKey(key)) Then
' must be the first pass so set the current group to group
ht.Add(key, g)
Else
If Not (ht(key).Equals(g)) Then
ht(key) = g
End If
End If
End If
Return ht(key)
End Function
Using this exprssion in the textbox of the reportheader:
=Code.SetGroupHeader(ReportItems!Language.Value,"GroupName", User!UserID)
Links belowe about the hashtable and the mutiple threads safe problem for your reference:
http://stackoverflow.com/questions/2067537/ssrs-code-shared-variables-and-simultaneous-report-execution
http://sqlserverbiblog.wordpress.com/2011/10/10/using-custom-code-functions-in-reporting-services-reports/
If you still have any problem, please feel free to ask.
Regards
Vicky Liu -
Memory leaks and multi threading issues in managed client.
In our company we use a lot of Oracle, and after the release of the managed provider we migrated all applications to it. First the things were very impressive : the new client was faster, but after some days applications that uses 100MB with old client goes to 1GB and up. The memory is not the only issue, we use a lot of multi threading, and we experience connection drops and not disposal, after 1 days working one of the application had over 100 sessions on the server. I think there is something wrong with connection pool and multi threading.
Is someone experience same problems.
Yesterday we went back with unmanaged provider. Now things are back to normal.connection drops: did you try to use "Validate Connection=true" parameter in your connection string?
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Multi-Threaded FTP was a huge attraction for me, and one of the features that sold me on upgrading to Dreamweaver CS6. However, I haven't seen any sign of it in the product or any documentation to help me use it. My files keep transferring in the traditional one-at-a-time way.
Is there something I need to do to enable this feature? Has anybody used this feature yet?Might not help but I saw this in the comments on David Powers' blog
http://foundationphp.com/blog/2012/04/23/my-verdict-on-dreamweaver-cs6/
"Multi-thread FTP is the default in Dreamweaver CS6. You can neither turn it on nor off. It handles a maximum of three transfers simultaneously in either direction (so you can download at the same time as uploading). However, it doesn’t work with Check In/Check Out."
He also has the following comments in the body of the blog entry:
Multichannel FTP
Let’s be honest. In the past, Dreamweaver’s FTP client was a dog. Not any more. It now supports multichannel transfers, and can even download at the same time as uploading. Orange arrows indicate items queued for transfer. When the transfer begins, the arrow turns green. And if you’re transferring a large item, hovering over the filename displays a tooltip of how much of the file has been transferred. With Dreamweaver CS5.5, it took more than 90 minutes to upload a WordPress site on my internet connection. Now, it’s more than ten times faster.
The FTP error messages are also more meaningful. No one is likely to buy Dreamweaver CS6 for its FTP client alone, but this is a major improvement to the program. -
Running a Java Multi Thread Program in database
I have created a multi threaded program in Java and it runs successfully from the command prompt. I want to create a DBMS Job which will wake up at regular intervals and runs the java program(Java stored procedure). Is this possible in 9.2/10G ?? If Yes, will there be any impact on the DB performance/increase memory etc.,
The database (9.2...) resides on a RH 2.3 AS box.
Any ideas...
Thanks,
PurushPurush,
Java stored procedures cannot be multi-threaded. Well, they can, but the threads will not run in parallel. You may be able to find some more information in the Oracle documentation, which is available from:
http://tahiti.oracle.com
Good Luck,
Avi.
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