Delims for StringTokenizer
I need to add " to the Tokenizer as a delim I used to know how to do this but it seems to be slipping my mind. Currently this is what my statment looks like:
String delimvar = "<> ";
This is using the < > and whitespace as my seperators. and I want to add the " character to it aswell.
I know i cannot simply put " into the string because then I get a 'unclosed string literal' message.
any hely would be great
awsome thankyou, i just tried that too.. I was trying / before not \ it works perfect now...
Similar Messages
-
"**" to be delimiter!! not only "*" what can I do!!???for StringTokenizer
In my work
If I have an equation, a+b**c+d*e
** means exponent. so b^c (but I should do that way **)
there are 5different operators ---> ** + - / *
so...I'm trying to use StringTokenizer.
such that,
StringTokenizer st = new StringTokenizer(String, "*/+-", true)
even if I make (String,"*/+-**", true) ,it does not work.
Is there any way I can do that??
please somebody help me....As the StringTokenizer API doc says: All characters in the delim argument are the delimiters for separating tokens
In other words, only single characters are used as separators.
You might consider using Pattern and Matcher.
For example: String input = "a+b**c+d*e";
Pattern pattern = Pattern.compile("[+\\-/]|\\*{1,2}|\\w+");
Matcher matcher = pattern.matcher(input);
while(matcher.find()) {
System.out.println(matcher.group());
} -
Multiple delimiters for StringTokenizer
If I am trying to parse a string which has multiple delimiters like
13:10_76.5
How do I tell the string tokenizer that : _ . (colon, underscore, period) are all delimiters? Or can I?
Thanks,
WFConstructs a string tokenizer for the specified
string. The characters in the delim argument are
the delimiters for separating tokens.
Delimiter characters themselves will not be treated as
tokens.
[b]Parameters:
str - a string to be parsed.
delim - the delimiters[u].
Okay, I am new at this and perhaps I am missing something obvious, but if my string name is "inputstring''
this should look like this: public StringTokenizer(inputstring, :_.) ??
I am trying to parse out the stuff between these delimiters like in this example 13:10_78.5
If I want 13 then 10 then 78 then 5 pulled out, how do I get it to do that? Is that more clear??
Thanks for your patience!
Wf -
Need code example for StringTokenizer to hashmap...
I am creating a rolodex with name, phone, address, city, state. The data will be saved to a delimited file. When the app begins I have to read the file to get the records into memory. My GUI will list the names. The user should be able to click on one of the names to open a dialog box in which all the fields will appear and wil be editable.
I need some assistance with design...
I think I should use BufferedReader and StringTokenizer for reading the file in. Then perhaps store the records in a hashmap(need help with that - Is hashmap the thing to use? Maybe arraylist instead? How do i do it?) The records should be stored sorted by name in memory and in the file. Next, I figure I can show the names using a table and hide the other columns, when a cell is clicked I can pop up the dialog box with all the goodies in it. When I save it should be to memory, how do I do that? Then when the app closes I will write out using PrintWriter.
There are other things going on, buttons, listeners, etc. but the basic design is what I need advice on. Any ideas are welcome and appreciated!From the name to get the record, clearly you need a effecient lookup mechnism.
HashMap does hash lookup, that is right, but HashMap does NOT do ordering.
TreeMap does binary lookup, TreeMap also does ordering.
There you go the basic design.
--lichu -
INFOTYPE 0034 - Time Constraint for Subtypes Issue
Experts,
I have an issue, our organisation maintains many subtypes for infogype 0034, and we want to delimit the previous entry regardless the subtype (same problem as yours) and i am not able to make it work the way we want..
Example :
employee joins the organisation and has the subtype '07' - home worker- for Infotype 0034 with following dates :
Start date : 01.01.2010
End date : 31.12.9999
now at a later date, the subtype of infotype changes as '09' - factory worker - for infotype 0034 with following dates :
Start date : 04.05.2010
End date : 31.12.9999
now, as we make an entry for subtype '09' with starting date as 04.05.2010 it should delimit the previous entry and the previous entry should have following dates
Starte date : 01.01.2010
End date : 03.05.2010
i have tried changing TC for IT 0034 in V_T582A to 'T' and TCs for subtypes as '1' in V_T591A as i found response for similar to this issue in one of the threads, but it does not resolve my issue
so, can experts suggest me what shall i do to make the IT 0034 behave in way that whenever there is a new entry for subtype it delimits the old entry (regardless of subtypes)?
Response will be highly appreciated
Thanks
JalpaHi,
Please check the threads.
Re: Subtype wise record delimit for IT-0034 .
You can also check the user exit.. EXIT_SAPFP50M_002,LXPADU01.
Thanks & Regards,
Sandip Biswas. -
hi, i am receiving the following error message:
MyBot.java:611: cannot resolve symbol
symbol: class StringTokenizer
location: class MyBot
StringTokenizer t = new StringTokenizer(s,"@");
repeated twice, with one arrow pointing at the first mention
of StringTokenizer and the other arrow at the other mention.
The file MyBot.java has the following import clauses:
import java.util.Date;
import java.util.Random;
import java.io.*;
import GooglePack.*;
import java.lang.*;
which i thought were sufficient for StringTokenizer,
but obviously not :(
i use StringTokenizer as follows:
StringTokenizer t = new StringTokenizer(s,"@");
String rnick = t.nextToken();
String rhost = t.nextToken();
String rdate = t.nextToken();
String reol = t.nextToken();
Any help would be much appreciated,
cameronAlways use the java documentation bundle for the SDK. You can look up a class for free in an indexed HTML and see all the fields, methods, constructors, related classes and yes, it's package.
Talden -
Hi All,
I want to know if there is any function in J2ME like StringTokenizer for Java.
Is there any way to convert a long string into tokens,which can be accessed sequentially.
Will Vector or any other function in J2ME help.
Help me out guys,
Bye,
SangramHi
I tried what you said , but its not working
I have a java file for stringtokenizer. I tried compiling it in netbeans mobility pack 4.1.But it gives the error as " Cannot find symbol stringtokenizer ".
So. please can u illustrate more on what u said
What did u mean by J2SE source?
Thanks -
Multiple Command Line Arguments
My professor likes to enter input all on one line, as in the following input example:
Burns CS130 110 90 80 70 60 50 40 20 10
First is a Name, second is a class name, followed by a series of grades.
My question is:
1) Is this something that should be read into the program using StringTokenizer, and
2) How would one use StringTokenizer to read in this information.
I understand BufferedReader, but am still having issues understanding StringTokenizer. Any help would be appreciated.
Thank you!hoping for the duke dollars
This depends on when this input is occuring. Is this input occuring when you start your program?
i.e.
java myprog blah blah 234 33 a a
or is this input happening at run-time while the program is running (i.e. by using System.in) then this could be a potential use for StringTokenizer.
You can initialize StringTokenizer with whatever delimiter you want using this constructor:
public StringTokenizer(String str,
String delim)
In your case, your delimiter would be the space character " "
So you could do this:
StringTokenizer inputTokenizer = new StringTokenizer (inputString, " ");
Then you could:
String token = new String();
while (inputTokenizer.hasMoreTokens()) {
println(inputTokenizer.nextToken());
token = inputTokenizer.nextToken();
// you could put the string "token" into a String array on this line
Let me know if I can provide any additional assistance,
Tim
[email protected] -
hi - i am attempting to parse values out of a text file using stringTokenizer. The values are delimited by a "<br>" tag. When I pass this to the stringTokenizer, I get some weird results making me think that it will only accept a single character as the delimiter: Example:
This is the text of a file that would be parsed
partText=<b>Transynd LLC.</b><br>Ken Lewis<br>303.641.5542<br>[email protected]<br>www.transynd.com
After extracting this text from the file, it is set to the var 'news'. stringTokenizer is then applied as such:
StringTokenizer st = new StringTokenizer(news, "<br>");
while (st.hasMoreTokens())
out.write(st.nextToken() " ");
The expected resulting html is:
patText=Tansynd LLC Ken Lewis 303.641.5542 [email protected] www.tansynd.com
but in reality, i am getting:
patText=Tansynd LLC./ Ken Lewis 303.641.5542 [email protected] www.tansynd.com
notice that it removed most of the opening and closing bold tags - no idea why. and left the '/' from the closing bold tag - again no idea why.
NOTE: i am having it write to html just for testing purposes. in actuality, i will be building an array of these values so that they can be accessed later.
Any ideas how i can parse these values using "<br>" as my delimiter? Any help would be greatly appreciated.
-dFrom the javadoc for StringTokenizer constructor:
public StringTokenizer(String str,
String delim)
Constructs a string tokenizer for the specified string. The characters in the delim argument are the delimiters for separating tokens. Delimiter characters themselves will not be treated as tokens.
So the string is being split on any instance of '<', 'b', 'r', or '>'. It doesn't look like you're going to be able to use StringTokeizer to do what you want. You will probably have to write your own tokenizer. You can use String.indexOf( String ) to find out where "<br>" is in your string, and then use String.subString( int, int ) to extract the chars between the <br> tags. -
Hi,
I want to parse a string which can contain x number of up/down arrows.
These are represented by the unicode codes of \u2191and \u2193. Now i need to extract the positions of all of these items and replace the text with spaces where an arrow appears.
What is the best way to do this. Im thinking of using the stringtokenizer and getting setting the delim for the up and down arrows. However once I have these tokens I cant fiqure a way to replace the original text with spaces where these appear.
Any good suggestions?
ThanksIf you know the number of arrows, you can use an array.
If you don't know the number, you can either use an array with the same size as the char array (worst case), or use a Vector/ArrayList. Perhaps make a class that can hold the position and direction:
class Arrow {
public static final char UP = '\u2191'; // dunno if this is up or down char
public static final char DOWN = '\u2193';
private final int pos;
private final char direction;
public Arrow(int pos, char direction) {
this.pos = pos;
this.direction = direction;
public int getPos() { return pos; }
public String getDirection() {
if (direction == UP)
return "UP";
return "DOWN";
ArrayList pos = new ArrayList();
for (int x = 0; x < s.length(); x++) {
if (s.charAt(x) == '\u2191' || s.charAt(x == '\u2193') {
System.out.print(" ");
pos.add(new Arrow(x, s.charAt(x));
} else {
System.out.print(s.charAt(x);
// this is not an arrow.
for (int x = 0; x < pos.size(); x++) {
Arrow arrow = (Arrow)pos.get(x);
System.out.println("Arrow at pos: "+arrow.getPos()+" direction: "+arrow.getDirection());
} -
Why getResource of jar in classpath returns null?
When i iterate through the jars in the classpath and try to turn them into URL's via the getResources(), they all return null. What am I doing wrong?
(NOTE: It does print out the classpath properly when i print that out)
String classPath = System.getProperty( "java.class.path" );
String delim = System.getProperty( "path.separator" );
String[] locations = classPath.split( delim );
for ( int i = 0; i < locations.length; i++ )
/* ** It doesn't work with either of these statments: ** */
//This one tries the full path (e.g. /home/me/test/some.jar)
//Enumeration en = getClass().getClassLoader().getResources( locations[ i ].substring( locations[ i ] );
//This one tries to use just the local name of the jar (e.g. test.jar)
Enumeration en = getClass().getClassLoader().getResources( locations[ i ].substring( locations[ i ].lastIndexOf( '/' ) + 1 ) );
//This just prints null
while ( en.hasMoreElements(); ) System.out.println( en.nextElement() );
}Edited by: 6tr6tr on Dec 4, 2008 5:46 PM
Edited by: 6tr6tr on Dec 4, 2008 5:47 PMWhat you are doing doesn't make sense. The resource locations within a JAR file are relative to the package directory structure within the JAR file, not to its own absolute location on the disk. And you seem to be expecting to retrieve a JAR file from within a JAR file. This makes no sense either.
-
Hi Gurus,
i have got a problem,I need to do leaving action beyond the earliest retroactive-date in control record.Is there anyways to do without deleting the control record.Thanks
any inputs Plziam not sure
jsut check with the operations of personnel actions
generally we delimit for leaveing acions instead that take copy as acitons
and wait for other s
response -
Floating boxes applet with drag events need click event
I Have an applet cobbled from the net & modified. Is works but needs one major event added. It draws "Graphics.drawline" boxes with a text "String" inside each box ( the text string represents an URL location). These "boxes" are objects which are "draggable to other locations on canvas & therefore can be independently positioned by user. Each box redraws itself periodically to a slightly different screen location & becomes stationary after a 5 or 6 seconds. The point is, all of this "drag & mobility" behavior must remain intact & is not part of the "problem task".
Task: Need to have an "event" behavior added in one of two ways ( or a 3rd way if there is another ) whichever is quickest/ easiest. "Clickable mouse events" must be added to each box. ( boxes are built in a loop so adding to one will add to other locations & create as many "buttons" as there are boxes) . At each box's location, clicking one box should be an event which fires & clicking a different box should be a separate event which fires. Separate , so that URL location can be "hotlinked" to each box. That URL is currently displayed in the boxes (visible when running applet).
1st possible solution: Exchange these "boxes" which appear on canvas into clickable event "Graph panel.buttons" ( for example or some other clickable object) which maintains existing "drag" behavior of boxes. These buttons must each have "clickability" with mouse events to enable placing "getAppletContext. showDocument()" code with these events ( e.g., "hotlinked" to http locations).
or
2nd possible solution:. The drawstring boxes are currently dead string text with no event model other than the "drag" feature associated with each box. Must add an additional mouse event behavior to existing boxes so they are "clickable" ( or text inside is clickable) and can then execute "showDocument()" URL when clicked independently.
Maybe there is a #3. I don't know what that would be. Open to try anything without losing the drag & placement mobility of existing boxes.
These "boxes" could be images, or event buttons - doesnt matter.
Not sure if #2 is possible & have not been able to accomplish #1. Must stay within existing AWT framework so IE browsers can run it natively ( which of course IE cannot run Swing graphics unless a Sun plugin loaded ).
Applet is a single file ( creating 4 classes).
html file (which invokes it) passes a string param which is broken into above noted URL strings in each box.
Running this applet, you see a "button" event ( at base of canvas labeled "NewUrl" ) which pops up an url location when clicked ( using "showdocument"). This button is not attached to locations or text of each box object ( which is the "task" to accomplish) . The button does represent the kind of event behavior which each "box" should have when task is achieved. So the box can be exchanged with buttons or the boxes can be imbued with events to hyperlink like a button.
In spirit of solution #1, here is the bonehead attempt I tried which did not work: copied entire "if" block of logic from the button event (sited in preceding paragraph) into region of code which builds boxes ( "for" loop of "drawstring" method).
"g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());"
I copied all the "if" block of logic for button creation into the area immediately after the above line ( for loop which builds the boxes). Hoping that I could create buttons with events, along with all the boxes (which are getting created using "drawstring" above in a "for" loop). These "buttons" must also have positioning info of each box to appear in different locations on the canvas. Positioning data is not in that "if" block of code but it would have been a start to get the multiple buttons created ( even if all drawn in one spot). The "if" code block I've provieded for an example begins with the line:
" if ("NewUrl".equals(arg)) { "
and ends with with lines:
" return true; "
" } " //< -- end of above if block
This full "if" block can be seen in the listing below:
This "if" block creates the "NewUrl" button. Of course, I got a bunch of errors when I tried to copy this block to the above location:
variable: "arg" "not found in class GraphPanel".
methods: "getcodebase, showstatus, getappletcontext()"
"not found in class GraphPanel".
----------- The applet code in total follows next
Here are both the java & htm complete source.
import java.net.MalformedURLException;
import java.net.URL;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.applet.Applet;
import java.applet.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.*;
class Node {
double x;
double y;
double dx;
double dy;
boolean fixed;
String lbl;
class Edge {
int from;
int to;
double len;
} // eEdgeCla
class GraphPanel extends Panel implements Runnable {
Box box;
int nnodes;
Node nodes[] = new Node[100];
int nedges;
Edge edges[] = new Edge[200];
Thread relaxer;
boolean showit;
boolean random;
GraphPanel(Box box) {
this.box = box;
} //ebox
int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
if (nodes.lbl.equals(lbl)) {
return i;
return addNode(lbl);
int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
public void run() {
int i3=0;
while (true) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int) (1 * nnodes) ]; // no
if (!n.fixed) {
n.x += (100*0.02) - 50;
n.y += (100*0.02) - 50; //
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
break;
i3++;
} //ew
} // epublrun()
synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges;
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);
double f = (edges.len - len) / (len * 3) ;
double dx = f * vx;
double dy = f * vy;
nodes[e.to].dx += dx;
nodes[e.to].dy += dy;
nodes[e.from].dx += -dx;
nodes[e.from].dy += -dy;
} //efo
for (int i = 0 ; i < nnodes ; i++) {
Node n1 = nodes;
double dx = 0;
double dy = 0;
for (int j = 0 ; j < nnodes ; j++) {
if (i == j) {
continue;
Node n2 = nodes[j];
double vx = n1.x - n2.x;
double vy = n1.y - n2.y;
double len = vx * vx + vy * vy;
if (len == 0) {
dx += 0.02;
dy += 0.02;
} else if (len < 100*100) {
dx += vx / len;
dy += vy / len;
} //ef3a
double dlen = dx * dx + dy * dy;
if (dlen > 0) {
dlen = Math.sqrt(dlen) / 2;
n1.dx += dx / dlen;
n1.dy += dy / dlen;
} //ef3
Dimension d = size();
// f4
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes;
if (!n.fixed) {
n.x += Math.max(-5, Math.min(5, n.dx));
n.y += Math.max(-5, Math.min(5, n.dy));
if (n.x < 0) {
n.x = 0;
} else if (n.x > d.width) {
n.x = d.width;
if (n.y < 0) {
n.y = 0;
} else if (n.y > d.height) {
n.y = d.height;
n.dx /= 2;
n.dy /= 2;
repaint();
Node pick;
boolean pickfixed;
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;
final Color fixedColor = Color.green;
final Color selectColor = Color.gray;
final Color edgeColor = Color.black;
final Color nodeColor = new Color(200, 90, 50);
final Color showitColor = Color.gray;
final Color arcColor1 = Color.black;
final Color arcColor2 = Color.orange;
final Color arcColor3 = Color.blue;
public void paintNode( Graphics g, Node n, FontMetrics fm) {
int x = (int)n.x;
int y = (int)n.y;
g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor));
int w = fm.stringWidth(n.lbl) + 10;
int h = fm.getHeight() + 4;
g.fillRect(x - w/2, y - h / 2, w, h);
g.setColor(Color.black);
g.drawRect(x - w/2, y - h / 2, w-1, h-1);
String doit = n.lbl.replace('x','/');
g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());
} // epa
public synchronized void update(Graphics g) {
Dimension d = size();
if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges;
int x1 = (int)nodes[e.from].x;
int y1 = (int)nodes[e.from].y;
int x2 = (int)nodes[e.to].x;
int y2 = (int)nodes[e.to].y;
int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);
offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;
offgraphics.drawLine(x1, y1, x2, y2);
if (showit) {
String lbl = String.valueOf(len);
offgraphics.setColor(showitColor);
offgraphics.drawString("href= http://localhost:"+lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
offgraphics.setColor(edgeColor);
} //ef5
FontMetrics fm = offgraphics.getFontMetrics();
for (int i = 0 ; i < nnodes ; i++) {
paintNode( offgraphics, nodes, fm); //or
g.drawImage(offscreen, 0, 0, null);
public synchronized boolean mouseDown(Event evt, int x, int y) {
double bestdist = Double.MAX_VALUE;
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes;
double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
if (dist < bestdist) {
pick = n;
bestdist = dist;
pickfixed = pick.fixed;
pick.fixed = true;
pick.x = x;
pick.y = y;
repaint();
return true;
public synchronized boolean mouseDrag(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
repaint();
return true;
} //e-pubsyncmousedrag
public synchronized boolean mouseUp(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
pick.fixed = pickfixed;
pick = null;
repaint();
return true;
public void start() {
relaxer = new Thread(this);
relaxer.start();
public void stop() {
relaxer.stop();
public class Box extends Applet {
GraphPanel panel;
public void init() {
setLayout(new BorderLayout());
panel = new GraphPanel(this);
add("Center", panel);
Panel p = new Panel();
add("South", p);
p.add(new Button("Reposition"));
p.add(new Button("NewUrl"));
p.add(new Checkbox("Showit"));
String edges = getParameter("edges"); // putinli
for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
String str = t.nextToken();
int i = str.indexOf('-');
if (i > 0) { int len = 50;
int j = str.indexOf('/');
if (j > 0) {
len = Integer.valueOf(str.substring(j+1)).intValue();
str = str.substring(0, j);
panel.addEdge(str.substring(0,i), str.substring(i+1), len);
} //ef8
Dimension d = size();
String center = getParameter("center");
if (center != null){
Node n = panel.nodes[panel.findNode(center)];
n.x = d.width / 2;
n.y = d.height / 2;
n.fixed = true;
} // eif
} // ep
public void start() {
panel.start();
public void stop() {
panel.stop();
public boolean action(Event evt, Object arg) {
if (arg instanceof Boolean) {
if (((Checkbox)evt.target).getLabel().equals("Showit")) {
panel.showit = ((Boolean)arg).booleanValue();
}// e-
else {
panel.random = ((Boolean)arg).booleanValue();
return true;
} // e-if instof bool
if ("Reposition".equals(arg)) {
Dimension d = size();
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes;
if (!n.fixed) {
n.x = 10 + (d.width-20)*Math.random();
n.y = 10 + (d.height-20)*Math.random();
} //ei
} //ef9
return true;
} //eif scram
if ("NewUrl".equals(arg)) {
Dimension d = size();
URL url = getCodeBase();
try {
getAppletContext().showDocument( new URL(url+"main.htm"), "_blank" );
try {
Thread.sleep(1000);
} catch (InterruptedException e) { }
} catch(MalformedURLException e) {
showStatus("814 URL not found");
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes;
if (!n.fixed) {
n.x += (80*0.02) - 40;
n.y += (80*0.02) - 40;
return true;
} //ei
return false;
-----------------------htm file to launch------------------------------
<html>
<head>
<title>R
</title>
</head>
<body>
<h3>
<center>
R
</center>
</h3>
I
<b>
</b>
<table border = 1>
<td>De<td>Test List<tr>
<td>N <td><tr>
<td>N <td><tr>
</table>
<b>view </b>
<applet code="Box.class" CODEBASE=. width=1000 height=600
ALT="Test ">
<param name=edges value="http:xxabc.htm-http:xxnet.htm,http:xxthis.htm-http:xx.comet.htm,http:xxnewsighting.htm-http:xxstar.htm,http:xxmoon.htm-http:xxNeptune.htm">
<hr>
</applet>
</b>
<p>
<table border = 1>
<tr>
<tr>
</table>
</html>
</body>
instructions to compile :
0 : The discussion becomes easy to follow after 1st compiling
& viewing the applet.
1. : cut out applet code.
2. : the post somehow deleted all references to "" <--- HERE
see, the data has been deleted again as I preview this post.
( that "" should contain an "i" array increment argument:
"open square bracket" "i" "close square bracket" ) array
so "javac Box.java" will get 10 errors. These "[" "i" "]"
array args must be replaced to compile the code.
3. : All array variables inside the 10 "for" loops ( the bare words
"edges" and "nodes" ) without array increment "i" should
read "edges" "[" "i" "]" & "nodes" "[" "i" "]".
The 10 location lines are approx:
line #65, #129, #136, #149, #195, #283, #311, #331, #477, #522
4. : These 10 edits reqresent a missing "i" to all 10 for loop arrays.
for eddges & nodes. fix this & javac Box.java" will get
4 class files.
5. : cut "Box.htm" from post & do "appletviewer Box.htm"
or put in an apache "htdoc" or tomcat "servlet" http delivered
directory & call "http://localhost/Box.htm.
6. : of course, selecting the event button "NewUrl" will not
work in appletviewer but will work in an http web location.
7. : post your questions to problem or fixes to problem as I'm
monitoring closely. TIA.Thanks for code post tip to fix array deletion problem.
Here is code reposted using delimiters with will
compile straight out of cut/paste.import java.net.MalformedURLException;
import java.net.URL;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.applet.Applet;
import java.applet.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.*;
class Node {
double x;
double y;
double dx;
double dy;
boolean fixed;
String lbl;
class Edge {
int from;
int to;
double len;
} // eEdgeCla
class GraphPanel extends Panel implements Runnable {
Box box;
int nnodes;
Node nodes[] = new Node[100];
int nedges;
Edge edges[] = new Edge[200];
Thread relaxer;
boolean showit;
boolean random;
GraphPanel(Box box) {
this.box = box;
} //ebox
int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
//if (nodes.lbl.equals(lbl)) {
if (nodes.lbl.equals(lbl)) {
return i;
return addNode(lbl);
int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
public void run() {
int i3=0;
while (true) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int) (1 * nnodes) ]; // no
if (!n.fixed) {
n.x += (100*0.02) - 50;
n.y += (100*0.02) - 50; //
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
break;
i3++;
} //ew
} // epublrun()
synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
//Edge e = edges;
Edge e = edges[i];
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);
//double f = (edges.len - len) / (len * 3) ;
double f = (edges[i].len - len) / (len * 3) ;
double dx = f * vx;
double dy = f * vy;
nodes[e.to].dx += dx;
nodes[e.to].dy += dy;
nodes[e.from].dx += -dx;
nodes[e.from].dy += -dy;
} //efo
for (int i = 0 ; i < nnodes ; i++) {
//Node n1 = nodes[i];
Node n1 = nodes[i];
double dx = 0;
double dy = 0;
for (int j = 0 ; j < nnodes ; j++) {
if (i == j) {
continue;
Node n2 = nodes[j];
double vx = n1.x - n2.x;
double vy = n1.y - n2.y;
double len = vx * vx + vy * vy;
if (len == 0) {
dx += 0.02;
dy += 0.02;
} else if (len < 100*100) {
dx += vx / len;
dy += vy / len;
} //ef3a
double dlen = dx * dx + dy * dy;
if (dlen > 0) {
dlen = Math.sqrt(dlen) / 2;
n1.dx += dx / dlen;
n1.dy += dy / dlen;
} //ef3
Dimension d = size();
// f4
for (int i = 0 ; i < nnodes ; i++) {
//Node n = nodes;
Node n = nodes[i];
if (!n.fixed) {
n.x += Math.max(-5, Math.min(5, n.dx));
n.y += Math.max(-5, Math.min(5, n.dy));
if (n.x < 0) {
n.x = 0;
} else if (n.x > d.width) {
n.x = d.width;
if (n.y < 0) {
n.y = 0;
} else if (n.y > d.height) {
n.y = d.height;
n.dx /= 2;
n.dy /= 2;
repaint();
Node pick;
boolean pickfixed;
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;
final Color fixedColor = Color.green;
final Color selectColor = Color.gray;
final Color edgeColor = Color.black;
final Color nodeColor = new Color(200, 90, 50);
final Color showitColor = Color.gray;
final Color arcColor1 = Color.black;
final Color arcColor2 = Color.orange;
final Color arcColor3 = Color.blue;
public void paintNode( Graphics g, Node n, FontMetrics fm) {
int x = (int)n.x;
int y = (int)n.y;
g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor));
int w = fm.stringWidth(n.lbl) + 10;
int h = fm.getHeight() + 4;
g.fillRect(x - w/2, y - h / 2, w, h);
g.setColor(Color.black);
g.drawRect(x - w/2, y - h / 2, w-1, h-1);
String doit = n.lbl.replace('x','/');
g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());
} // epa
public synchronized void update(Graphics g) {
Dimension d = size();
if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i = 0 ; i < nedges ; i++) {
//Edge e = edges;
Edge e = edges[i];
int x1 = (int)nodes[e.from].x;
int y1 = (int)nodes[e.from].y;
int x2 = (int)nodes[e.to].x;
int y2 = (int)nodes[e.to].y;
int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);
offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;
offgraphics.drawLine(x1, y1, x2, y2);
if (showit) {
String lbl = String.valueOf(len);
offgraphics.setColor(showitColor);
offgraphics.drawString("href= http://localhost:"+lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
offgraphics.setColor(edgeColor);
} //ef5
FontMetrics fm = offgraphics.getFontMetrics();
for (int i = 0 ; i < nnodes ; i++) {
//paintNode( offgraphics, nodes, fm); //or
paintNode( offgraphics, nodes[i], fm); //or
g.drawImage(offscreen, 0, 0, null);
public synchronized boolean mouseDown(Event evt, int x, int y) {
double bestdist = Double.MAX_VALUE;
for (int i = 0 ; i < nnodes ; i++) {
//Node n = nodes;
Node n = nodes[i];
double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
if (dist < bestdist) {
pick = n;
bestdist = dist;
pickfixed = pick.fixed;
pick.fixed = true;
pick.x = x;
pick.y = y;
repaint();
return true;
public synchronized boolean mouseDrag(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
repaint();
return true;
} //e-pubsyncmousedrag
public synchronized boolean mouseUp(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
pick.fixed = pickfixed;
pick = null;
repaint();
return true;
public void start() {
relaxer = new Thread(this);
relaxer.start();
public void stop() {
relaxer.stop();
public class Box extends Applet {
GraphPanel panel;
public void init() {
setLayout(new BorderLayout());
panel = new GraphPanel(this);
add("Center", panel);
Panel p = new Panel();
add("South", p);
p.add(new Button("Reposition"));
p.add(new Button("NewUrl"));
p.add(new Checkbox("Showit"));
String edges = getParameter("edges"); // putinli
for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
String str = t.nextToken();
int i = str.indexOf('-');
if (i > 0) { int len = 50;
int j = str.indexOf('/');
if (j > 0) {
len = Integer.valueOf(str.substring(j+1)).intValue();
str = str.substring(0, j);
panel.addEdge(str.substring(0,i), str.substring(i+1), len);
} //ef8
Dimension d = size();
String center = getParameter("center");
if (center != null){
Node n = panel.nodes[panel.findNode(center)];
n.x = d.width / 2;
n.y = d.height / 2;
n.fixed = true;
} // eif
} // ep
public void start() {
panel.start();
public void stop() {
panel.stop();
public boolean action(Event evt, Object arg) {
if (arg instanceof Boolean) {
if (((Checkbox)evt.target).getLabel().equals("Showit")) {
panel.showit = ((Boolean)arg).booleanValue();
}// e-
else {
panel.random = ((Boolean)arg).booleanValue();
return true;
} // e-if instof bool
if ("Reposition".equals(arg)) {
Dimension d = size();
for (int i = 0 ; i < panel.nnodes ; i++) {
//Node n = panel.nodes;
Node n = panel.nodes[i];
if (!n.fixed) {
n.x = 10 + (d.width-20)*Math.random();
n.y = 10 + (d.height-20)*Math.random();
} //ei
} //ef9
return true;
} //eif scram
if ("NewUrl".equals(arg)) {
Dimension d = size();
URL url = getCodeBase();
try {
getAppletContext().showDocument( new URL(url+"main.htm"), "_blank" );
try {
Thread.sleep(1000);
} catch (InterruptedException e) { }
} catch(MalformedURLException e) {
showStatus("814 URL not found");
for (int i = 0 ; i < panel.nnodes ; i++) {
//Node n = panel.nodes;
Node n = panel.nodes[i];
if (!n.fixed) {
n.x += (80*0.02) - 40;
n.y += (80*0.02) - 40;
return true;
} //ei
return false; -
Floating "boxes" applet with drag events need ckick events
I Have an applet cobbled from the net & modified. Is works but needs one major event added. It draws "Graphics.drawline" boxes with a text "String" inside each box ( the text string represents an URL location). These "boxes" are objects which are "draggable to other locations on canvas & therefore can be independently positioned by user. Each box redraws itself periodically to a slightly different screen location & becomes stationary after a 5 or 6 seconds. The point is, all of this "drag & mobility" behavior must remain intact & is not part of the "problem task".
Task: Need to have an "event" behavior added in one of two ways ( or a 3rd way if there is another ) whichever is quickest/ easiest. "Clickable mouse events" must be added to each box. ( boxes are built in a loop so adding to one will add to other locations & create as many "buttons" as there are boxes) . At each box's location, clicking one box should be an event which fires & clicking a different box should be a separate event which fires. Separate , so that URL location can be "hotlinked" to each box. That URL is currently displayed in the boxes (visible when running applet).
1st possible solution: Exchange these "boxes" which appear on canvas into clickable event "Graph panel.buttons" ( for example or some other clickable object) which maintains existing "drag" behavior of boxes. These buttons must each have "clickability" with mouse events to enable placing "getAppletContext. showDocument()" code with these events ( e.g., "hotlinked" to http locations).
or
2nd possible solution:. The drawstring boxes are currently dead string text with no event model other than the "drag" feature associated with each box. Must add an additional mouse event behavior to existing boxes so they are "clickable" ( or text inside is clickable) and can then execute "showDocument()" URL when clicked independently.
Maybe there is a #3. I don't know what that would be. Open to try anything without losing the drag & placement mobility of existing boxes.
These "boxes" could be images, or event buttons - doesnt matter.
Not sure if #2 is possible & have not been able to accomplish #1. Must stay within existing AWT framework so IE browsers can run it natively ( which of course IE cannot run Swing graphics unless a Sun plugin loaded ).
Applet is a single file ( creating 4 classes).
html file (which invokes it) passes a string param which is broken into above noted URL strings in each box.
Running this applet, you see a "button" event ( at base of canvas labeled "NewUrl" ) which pops up an url location when clicked ( using "showdocument"). This button is not attached to locations or text of each box object ( which is the "task" to accomplish) . The button does represent the kind of event behavior which each "box" should have when task is achieved. So the box can be exchanged with buttons or the boxes can be imbued with events to hyperlink like a button.
In spirit of solution #1, here is the bonehead attempt I tried which did not work: copied entire "if" block of logic from the button event (sited in preceding paragraph) into region of code which builds boxes ( "for" loop of "drawstring" method).
"g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());"
I copied all the "if" block of logic for button creation into the area immediately after the above line ( for loop which builds the boxes). Hoping that I could create buttons with events, along with all the boxes (which are getting created using "drawstring" above in a "for" loop). These "buttons" must also have positioning info of each box to appear in different locations on the canvas. Positioning data is not in that "if" block of code but it would have been a start to get the multiple buttons created ( even if all drawn in one spot). The "if" code block I've provieded for an example begins with the line:
" if ("NewUrl".equals(arg)) { "
and ends with with lines:
" return true; "
" } " //< -- end of above if block
This full "if" block can be seen in the listing below:
This "if" block creates the "NewUrl" button. Of course, I got a bunch of errors when I tried to copy this block to the above location:
variable: "arg" "not found in class GraphPanel".
methods: "getcodebase, showstatus, getappletcontext()"
"not found in class GraphPanel".
----------- The applet code in total follows next
Here are both the java & htm complete source.
import java.net.MalformedURLException;
import java.net.URL;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.applet.Applet;
import java.applet.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.*;
class Node {
double x;
double y;
double dx;
double dy;
boolean fixed;
String lbl;
class Edge {
int from;
int to;
double len;
} // eEdgeCla
class GraphPanel extends Panel implements Runnable {
Box box;
int nnodes;
Node nodes[] = new Node[100];
int nedges;
Edge edges[] = new Edge[200];
Thread relaxer;
boolean showit;
boolean random;
GraphPanel(Box box) {
this.box = box;
} //ebox
int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
if (nodes.lbl.equals(lbl)) {
return i;
return addNode(lbl);
int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
public void run() {
int i3=0;
while (true) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int) (1 * nnodes) ]; // no
if (!n.fixed) {
n.x += (100*0.02) - 50;
n.y += (100*0.02) - 50; //
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
break;
i3++;
} //ew
} // epublrun()
synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges;
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);
double f = (edges.len - len) / (len * 3) ;
double dx = f * vx;
double dy = f * vy;
nodes[e.to].dx += dx;
nodes[e.to].dy += dy;
nodes[e.from].dx += -dx;
nodes[e.from].dy += -dy;
} //efo
for (int i = 0 ; i < nnodes ; i++) {
Node n1 = nodes;
double dx = 0;
double dy = 0;
for (int j = 0 ; j < nnodes ; j++) {
if (i == j) {
continue;
Node n2 = nodes[j];
double vx = n1.x - n2.x;
double vy = n1.y - n2.y;
double len = vx * vx + vy * vy;
if (len == 0) {
dx += 0.02;
dy += 0.02;
} else if (len < 100*100) {
dx += vx / len;
dy += vy / len;
} //ef3a
double dlen = dx * dx + dy * dy;
if (dlen > 0) {
dlen = Math.sqrt(dlen) / 2;
n1.dx += dx / dlen;
n1.dy += dy / dlen;
} //ef3
Dimension d = size();
// f4
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes;
if (!n.fixed) {
n.x += Math.max(-5, Math.min(5, n.dx));
n.y += Math.max(-5, Math.min(5, n.dy));
if (n.x < 0) {
n.x = 0;
} else if (n.x > d.width) {
n.x = d.width;
if (n.y < 0) {
n.y = 0;
} else if (n.y > d.height) {
n.y = d.height;
n.dx /= 2;
n.dy /= 2;
repaint();
Node pick;
boolean pickfixed;
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;
final Color fixedColor = Color.green;
final Color selectColor = Color.gray;
final Color edgeColor = Color.black;
final Color nodeColor = new Color(200, 90, 50);
final Color showitColor = Color.gray;
final Color arcColor1 = Color.black;
final Color arcColor2 = Color.orange;
final Color arcColor3 = Color.blue;
public void paintNode( Graphics g, Node n, FontMetrics fm) {
int x = (int)n.x;
int y = (int)n.y;
g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor));
int w = fm.stringWidth(n.lbl) + 10;
int h = fm.getHeight() + 4;
g.fillRect(x - w/2, y - h / 2, w, h);
g.setColor(Color.black);
g.drawRect(x - w/2, y - h / 2, w-1, h-1);
String doit = n.lbl.replace('x','/');
g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());
} // epa
public synchronized void update(Graphics g) {
Dimension d = size();
if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges;
int x1 = (int)nodes[e.from].x;
int y1 = (int)nodes[e.from].y;
int x2 = (int)nodes[e.to].x;
int y2 = (int)nodes[e.to].y;
int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);
offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;
offgraphics.drawLine(x1, y1, x2, y2);
if (showit) {
String lbl = String.valueOf(len);
offgraphics.setColor(showitColor);
offgraphics.drawString("href= http://localhost:"+lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
offgraphics.setColor(edgeColor);
} //ef5
FontMetrics fm = offgraphics.getFontMetrics();
for (int i = 0 ; i < nnodes ; i++) {
paintNode( offgraphics, nodes, fm); //or
g.drawImage(offscreen, 0, 0, null);
public synchronized boolean mouseDown(Event evt, int x, int y) {
double bestdist = Double.MAX_VALUE;
for (int i = 0 ; i < nnodes ; i++) {
Node n = nodes;
double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
if (dist < bestdist) {
pick = n;
bestdist = dist;
pickfixed = pick.fixed;
pick.fixed = true;
pick.x = x;
pick.y = y;
repaint();
return true;
public synchronized boolean mouseDrag(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
repaint();
return true;
} //e-pubsyncmousedrag
public synchronized boolean mouseUp(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
pick.fixed = pickfixed;
pick = null;
repaint();
return true;
public void start() {
relaxer = new Thread(this);
relaxer.start();
public void stop() {
relaxer.stop();
public class Box extends Applet {
GraphPanel panel;
public void init() {
setLayout(new BorderLayout());
panel = new GraphPanel(this);
add("Center", panel);
Panel p = new Panel();
add("South", p);
p.add(new Button("Reposition"));
p.add(new Button("NewUrl"));
p.add(new Checkbox("Showit"));
String edges = getParameter("edges"); // putinli
for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
String str = t.nextToken();
int i = str.indexOf('-');
if (i > 0) { int len = 50;
int j = str.indexOf('/');
if (j > 0) {
len = Integer.valueOf(str.substring(j+1)).intValue();
str = str.substring(0, j);
panel.addEdge(str.substring(0,i), str.substring(i+1), len);
} //ef8
Dimension d = size();
String center = getParameter("center");
if (center != null){
Node n = panel.nodes[panel.findNode(center)];
n.x = d.width / 2;
n.y = d.height / 2;
n.fixed = true;
} // eif
} // ep
public void start() {
panel.start();
public void stop() {
panel.stop();
public boolean action(Event evt, Object arg) {
if (arg instanceof Boolean) {
if (((Checkbox)evt.target).getLabel().equals("Showit")) {
panel.showit = ((Boolean)arg).booleanValue();
}// e-
else {
panel.random = ((Boolean)arg).booleanValue();
return true;
} // e-if instof bool
if ("Reposition".equals(arg)) {
Dimension d = size();
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes;
if (!n.fixed) {
n.x = 10 + (d.width-20)*Math.random();
n.y = 10 + (d.height-20)*Math.random();
} //ei
} //ef9
return true;
} //eif scram
if ("NewUrl".equals(arg)) {
Dimension d = size();
URL url = getCodeBase();
try {
getAppletContext().showDocument( new URL(url+"main.htm"), "_blank" );
try {
Thread.sleep(1000);
} catch (InterruptedException e) { }
} catch(MalformedURLException e) {
showStatus("814 URL not found");
for (int i = 0 ; i < panel.nnodes ; i++) {
Node n = panel.nodes;
if (!n.fixed) {
n.x += (80*0.02) - 40;
n.y += (80*0.02) - 40;
return true;
} //ei
return false;
-----------------------htm file to launch------------------------------
<html>
<head>
<title>R
</title>
</head>
<body>
<h3>
<center>
R
</center>
</h3>
I
<b>
</b>
<table border = 1>
<td>De<td>Test List<tr>
<td>N <td><tr>
<td>N <td><tr>
</table>
<b>view </b>
<applet code="Box.class" CODEBASE=. width=1000 height=600
ALT="Test ">
<param name=edges value="http:xxabc.htm-http:xxnet.htm,http:xxthis.htm-http:xx.comet.htm,http:xxnewsighting.htm-http:xxstar.htm,http:xxmoon.htm-http:xxNeptune.htm">
<hr>
</applet>
</b>
<p>
<table border = 1>
<tr>
<tr>
</table>
</html>
</body>
instructions to compile :
0 : The discussion becomes easy to follow after 1st compiling
& viewing the applet.
1. : cut out applet code.
2. : the post somehow deleted all references to "" <--- HERE
see, the data has been deleted again as I preview this post.
( that "" should contain an "i" array increment argument:
"open square bracket" "i" "close square bracket" ) array
so "javac Box.java" will get 10 errors. These "[" "i" "]"
array args must be replaced to compile the code.
3. : All array variables inside the 10 "for" loops ( the bare words
"edges" and "nodes" ) without array increment "i" should
read "edges" "[" "i" "]" & "nodes" "[" "i" "]".
The 10 location lines are approx:
line #65, #129, #136, #149, #195, #283, #311, #331, #477, #522
4. : These 10 edits reqresent a missing "i" to all 10 for loop arrays.
for eddges & nodes. fix this & javac Box.java" will get
4 class files.
5. : cut "Box.htm" from post & do "appletviewer Box.htm"
or put in an apache "htdoc" or tomcat "servlet" http delivered
directory & call "http://localhost/Box.htm.
6. : of course, selecting the event button "NewUrl" will not
work in appletviewer but will work in an http web location.
7. : post your questions to problem or fixes to problem as I'm
monitoring closely. TIA.Thanks for code post tip to fix array index deletion problem.
Here is code reposted using "code" delimiters which will
compile straight out of cut/paste.
import java.net.MalformedURLException;
import java.net.URL;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.applet.Applet;
import java.applet.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.*;
class Node {
double x;
double y;
double dx;
double dy;
boolean fixed;
String lbl;
class Edge {
int from;
int to;
double len;
} // eEdgeCla
class GraphPanel extends Panel implements Runnable {
Box box;
int nnodes;
Node nodes[] = new Node[100];
int nedges;
Edge edges[] = new Edge[200];
Thread relaxer;
boolean showit;
boolean random;
GraphPanel(Box box) {
this.box = box;
} //ebox
int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
//if (nodes.lbl.equals(lbl)) {
if (nodes.lbl.equals(lbl)) {
return i;
return addNode(lbl);
int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
public void run() {
int i3=0;
while (true) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int) (1 * nnodes) ]; // no
if (!n.fixed) {
n.x += (100*0.02) - 50;
n.y += (100*0.02) - 50; //
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
break;
i3++;
} //ew
} // epublrun()
synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
//Edge e = edges;
Edge e = edges[i];
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);
//double f = (edges.len - len) / (len * 3) ;
double f = (edges[i].len - len) / (len * 3) ;
double dx = f * vx;
double dy = f * vy;
nodes[e.to].dx += dx;
nodes[e.to].dy += dy;
nodes[e.from].dx += -dx;
nodes[e.from].dy += -dy;
} //efo
for (int i = 0 ; i < nnodes ; i++) {
//Node n1 = nodes[i];
Node n1 = nodes[i];
double dx = 0;
double dy = 0;
for (int j = 0 ; j < nnodes ; j++) {
if (i == j) {
continue;
Node n2 = nodes[j];
double vx = n1.x - n2.x;
double vy = n1.y - n2.y;
double len = vx * vx + vy * vy;
if (len == 0) {
dx += 0.02;
dy += 0.02;
} else if (len < 100*100) {
dx += vx / len;
dy += vy / len;
} //ef3a
double dlen = dx * dx + dy * dy;
if (dlen > 0) {
dlen = Math.sqrt(dlen) / 2;
n1.dx += dx / dlen;
n1.dy += dy / dlen;
} //ef3
Dimension d = size();
// f4
for (int i = 0 ; i < nnodes ; i++) {
//Node n = nodes;
Node n = nodes[i];
if (!n.fixed) {
n.x += Math.max(-5, Math.min(5, n.dx));
n.y += Math.max(-5, Math.min(5, n.dy));
if (n.x < 0) {
n.x = 0;
} else if (n.x > d.width) {
n.x = d.width;
if (n.y < 0) {
n.y = 0;
} else if (n.y > d.height) {
n.y = d.height;
n.dx /= 2;
n.dy /= 2;
repaint();
Node pick;
boolean pickfixed;
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;
final Color fixedColor = Color.green;
final Color selectColor = Color.gray;
final Color edgeColor = Color.black;
final Color nodeColor = new Color(200, 90, 50);
final Color showitColor = Color.gray;
final Color arcColor1 = Color.black;
final Color arcColor2 = Color.orange;
final Color arcColor3 = Color.blue;
public void paintNode( Graphics g, Node n, FontMetrics fm) {
int x = (int)n.x;
int y = (int)n.y;
g.setColor((n == pick) ? selectColor : (n.fixed ? fixedColor : nodeColor));
int w = fm.stringWidth(n.lbl) + 10;
int h = fm.getHeight() + 4;
g.fillRect(x - w/2, y - h / 2, w, h);
g.setColor(Color.black);
g.drawRect(x - w/2, y - h / 2, w-1, h-1);
String doit = n.lbl.replace('x','/');
g.drawString(doit, x - (w-10)/2, (y - (h-4)/2) + fm.getAscent());
} // epa
public synchronized void update(Graphics g) {
Dimension d = size();
if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(getFont());
offgraphics.setColor(getBackground());
offgraphics.fillRect(0, 0, d.width, d.height);
for (int i = 0 ; i < nedges ; i++) {
//Edge e = edges;
Edge e = edges[i];
int x1 = (int)nodes[e.from].x;
int y1 = (int)nodes[e.from].y;
int x2 = (int)nodes[e.to].x;
int y2 = (int)nodes[e.to].y;
int len = (int)Math.abs(Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)) - e.len);
offgraphics.setColor((len < 10) ? arcColor1 : (len < 20 ? arcColor2 : arcColor3)) ;
offgraphics.drawLine(x1, y1, x2, y2);
if (showit) {
String lbl = String.valueOf(len);
offgraphics.setColor(showitColor);
offgraphics.drawString("href= http://localhost:"+lbl, x1 + (x2-x1)/2, y1 + (y2-y1)/2);
offgraphics.setColor(edgeColor);
} //ef5
FontMetrics fm = offgraphics.getFontMetrics();
for (int i = 0 ; i < nnodes ; i++) {
//paintNode( offgraphics, nodes, fm); //or
paintNode( offgraphics, nodes[i], fm); //or
g.drawImage(offscreen, 0, 0, null);
public synchronized boolean mouseDown(Event evt, int x, int y) {
double bestdist = Double.MAX_VALUE;
for (int i = 0 ; i < nnodes ; i++) {
//Node n = nodes;
Node n = nodes[i];
double dist = (n.x - x) * (n.x - x) + (n.y - y) * (n.y - y);
if (dist < bestdist) {
pick = n;
bestdist = dist;
pickfixed = pick.fixed;
pick.fixed = true;
pick.x = x;
pick.y = y;
repaint();
return true;
public synchronized boolean mouseDrag(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
repaint();
return true;
} //e-pubsyncmousedrag
public synchronized boolean mouseUp(Event evt, int x, int y) {
pick.x = x;
pick.y = y;
pick.fixed = pickfixed;
pick = null;
repaint();
return true;
public void start() {
relaxer = new Thread(this);
relaxer.start();
public void stop() {
relaxer.stop();
public class Box extends Applet {
GraphPanel panel;
public void init() {
setLayout(new BorderLayout());
panel = new GraphPanel(this);
add("Center", panel);
Panel p = new Panel();
add("South", p);
p.add(new Button("Reposition"));
p.add(new Button("NewUrl"));
p.add(new Checkbox("Showit"));
String edges = getParameter("edges"); // putinli
for (StringTokenizer t = new StringTokenizer(edges, ",") ; t.hasMoreTokens() ; ) {
String str = t.nextToken();
int i = str.indexOf('-');
if (i > 0) { int len = 50;
int j = str.indexOf('/');
if (j > 0) {
len = Integer.valueOf(str.substring(j+1)).intValue();
str = str.substring(0, j);
panel.addEdge(str.substring(0,i), str.substring(i+1), len);
} //ef8
Dimension d = size();
String center = getParameter("center");
if (center != null){
Node n = panel.nodes[panel.findNode(center)];
n.x = d.width / 2;
n.y = d.height / 2;
n.fixed = true;
} // eif
} // ep
public void start() {
panel.start();
public void stop() {
panel.stop();
public boolean action(Event evt, Object arg) {
if (arg instanceof Boolean) {
if (((Checkbox)evt.target).getLabel().equals("Showit")) {
panel.showit = ((Boolean)arg).booleanValue();
}// e-
else {
panel.random = ((Boolean)arg).booleanValue();
return true;
} // e-if instof bool
if ("Reposition".equals(arg)) {
Dimension d = size();
for (int i = 0 ; i < panel.nnodes ; i++) {
//Node n = panel.nodes;
Node n = panel.nodes[i];
if (!n.fixed) {
n.x = 10 + (d.width-20)*Math.random();
n.y = 10 + (d.height-20)*Math.random();
} //ei
} //ef9
return true;
} //eif scram
if ("NewUrl".equals(arg)) {
Dimension d = size();
URL url = getCodeBase();
try {
getAppletContext().showDocument( new URL(url+"main.htm"), "_blank" );
try {
Thread.sleep(1000);
} catch (InterruptedException e) { }
} catch(MalformedURLException e) {
showStatus("814 URL not found");
for (int i = 0 ; i < panel.nnodes ; i++) {
//Node n = panel.nodes;
Node n = panel.nodes[i];
if (!n.fixed) {
n.x += (80*0.02) - 40;
n.y += (80*0.02) - 40;
return true;
} //ei
return false; -
How do I send "unlimited" text in a parameter using "POST" in Ajax
I'm trying to send large amounts of text data to the server using POST rather than GET, using Ajax
However, I am only able to send a max of 9.76 kb
I start with a jsp page, which calls a javascript method that utilises Ajax, which sends the text in a parameter in a XMLHttpRequest object
to a servlet. The text is derived from options values in a multi select combo box.
Here's my code:
Code snippet from .jsp page:
<table>
<form name="form1" id="form1" method="POST">
<tr>
<td>
<select name="sel" id="sel" multiple="multiple" size="0"></select>
</td>
<td>
<input type="button" id="sendOpts" name="sendOpts" value="Send Options" onClick="jsObj.sendOpts()">
</td>
</tr>
</form>
</table>Code snippet from jsObj.js file:
//=================================================
// jsObj object
//=================================================
jsObj = new jsObj();
function jsObj() {
this.sendOpts = function() {
if(!confirm('Send Option Values?'))
return;
if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.onreadystatechange=function() {
if(xmlhttp.readyState==4) { // 4 = The request is complete
if (xmlhttp.status==200 || window.location.href.indexOf("http")==-1) {
alert(xmlhttp.responseText); // When I copy and paste all the text from this alert to text editor and save the file, the largest the file can be is 9.76 kb.
var url = 'testSize'; // Servlet that simply retrieves the sent String in a parameter and sends it back to this method
var sel = document.getElementById('sel');
var str = sel.name + '=';
var delim = ':';
for(var i = 0; i < sel.length; i++) {
str += encodeURIComponent(sel.options.value + delim); // 'encodeURIComponent' encodes any special characters within the parameter values
xmlhttp.open("POST",url,true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); // This is needed for any POST request made via Ajax
xmlhttp.send(str); // send the parameter and it's value to the servlet
}Code snippet from 'testSize' servlet:package test;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.*;
public class TestSize extends HttpServlet {
public synchronized void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException,IOException {
PrintWriter out = null;
try {
response.setContentType("text/html");
out = response.getWriter();
String str = request.getParameter("sel");
str = str.substring(0, str.length()-1); // cut off last delimiter
out.println(str);
} catch (Exception e) {
public synchronized void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}Any help greatly appreciated.
Edited by: Irish_Fred on Feb 25, 2010 5:14 AMYes, I tried that.
I set the "ACTION" of the form to the servlet and then used the form.submit() method to POST the text to the servlet.
i.e.: I selected many options in the select combo, concatenated them to one string, set the 'value' property of a form text field to
this string, did a 'form.submit()' to the servlet and I was able to send a much larger amount of text.
( The .txt file I saved from the resulting text equaled about 30 kb in size, so obviously I can send much more
data this way. )
However, I want to use Ajax, so I don't have to reload the page. I 'borrowed' the Ajax part of the code from a website:
http://www.javascriptkit.com/dhtmltutors/ajaxgetpost2.shtml
and I presumed that because the author used "POST" as opposed to "GET", I would be able to send larger
chunks of data. Obviously not, or there's another reason for the limit of data I can send using my present code,
which I'm not seeing. I'm fairly new to jsp, Ajax & Servlets, so this is no surprise.
If anyone can point out to me where I'm going wrong, I'd greatly appreciate it. Cheers.
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