Java Socket Connectivity
Hello,
i have created a server application that accepts socket connection from clients. Is there any way to determine from the server application if a client socket is still connected?
Thanks in advance
prasanna
Inside your reading of the data from the client, you should at least set some sort of var to isAlive, if you read -1 bytes from the client. That's the disconnect response from the client. I've also noticed that if you check if socket == null, that will work. When the client disconnects it sets it back to null.
-fetichico
Similar Messages
-
Java Socket Connection Time out
Goal*
I want to check host/port availability of computers in our network (~100 computers) .. Just check if host is alive and if it has port 445 opened. I want to do this somehow in parallel, so the code execution is as quick as possible.
My implementation*
I do this by creating socket connection to the host. Something like this:
Socket s = null;
try {
s = new Socket();
InetSocketAddress socketAddress = new InetSocketAddress(ipAddress, 445);
s.connect(socketAddress, 3000);
if (s.isConnected()) {
// do something
} catch (ConnectException ex) {
//exception thrown
} catch (IOException ex1) {
//exception thrown
} finally {
try {
// close socket
s.close();
} catch (IOException ex) {
Logger.getLogger(ComputerModel.class.getName()).log(Level.SEVERE, null, ex);
}This code is executed in a loop, where a separate thread is created for every iteration = ~100 separate threads.
Problem:*
1.
It seems to me, that first ~10-15 connections are created ok, but then my code reaches 'IOException' catch block for every subsequent itteration and ex.getMessage() returns "connection time out" (I try to use different timeout values in the 2nd parameter. Values from 3000 up to 20000).
Is it valid to create 100 separate threads in a loop? Can't I make my NIC to bussy with this ??? What is the maximum ammount of threads, I can create? I did not use threads before, so I have no idea, if max values are near to 10, 100, 1000, or 10000 ..
2.
After my code is executed, I enter 'netstat -an' command in my command line and I get bunch of connections, which report status of SYN_SENT for several connections.
TCP 10.20.11.140:4557 10.30.11.119:445 SYN_SENT
TCP 10.20.11.140:4558 10.30.11.176:445 SYN_SENT
TCP 10.20.11.140:4559 10.30.11.100:445 SYN_SENT
TCP 10.20.11.140:4560 10.30.11.142:445 SYN_SENT
TCP 10.20.11.140:4561 10.30.11.171:445 SYN_SENT
TCP 10.20.11.140:4562 10.30.11.143:445 SYN_SENT
TCP 10.20.11.140:4563 10.30.12.12:445 SYN_SENT
TCP 10.20.11.140:4564 10.30.12.11:445 SYN_SENT
TCP 10.20.11.140:4565 10.30.12.21:445 SYN_SENT
TCP 10.20.11.140:4566 10.30.11.150:445 SYN_SENT
I also feel, that my computer network response (e.g. firefox browsing) is a bit slower ..
How shall I handle this problem properly?
Thx in advance,
Jurajkajbj wrote:
tschodt wrote:
kajbj wrote:
The documentation for netstat explains what SYN_SENT is, but
I don't know why you have them.The app has asked the TCP stack to transmit SYN
the TCP stack is now waiting for SYN-ACK.
If there is no host at that IP address or a host that drops connections (SYN packets) for TCP port 445
there will never be a SYN-ACK.
After a few minutes the TCP stack will time out the connection attempt.Yes, I was rather commenting on why his hosts aren't answering. I thought that his case was that all of them should answer :)Akkurat. I was answering more for clarification.
Someone who does not know your posting history could easily assume you meant
it was a mystery why netstat was showing SYN_SENT.
And I figured it would not harm to hint that one possible reason would be that those machines are powered off (no host). -
Urgent --- Persistent socket connection?
Hi, I have a question about the persistency of a Java Socket connection. Is it a valid idea to keep a java socket open for a long time? If so, what special care do I need to take?
My Java TCP/IP client runs as a NT service. It keeps getting input messages every few seconds, then send it thru a socket connection to a TCP/IP server. In order to avoid the overhead of opening and closing the socket every time the client gets a message to send, I want to keep the socket connection open and reuse it.
I was able to send hundreds of messages thru this way, then after a while, for no apparent reason,
the socket stops working, I typically get an exception like this:
java.net.SocketException: Connection Shutdown: JVM_recv in socket input stream read
at java.net.SocketInputStream.socketRead(Native Method)
at java.net.SocketInputStream.read (SocketInputStream.java:90)
at java.net.SocketInputStream.read (SocketInputStream.java:71)
at java.io.InputStreamReader.fill (InputStreamReader.java:163)
at java.io.InputStreamReader.read (InputStreamReader.java:239)
at java.io.BufferedReader.fill (BufferedReader.java:137)
at java.io.BufferedReader.readLine (BufferedReader.java, Compiled Code)
at java.io.BufferedReader.readLine (BufferedReader.java:329)
My programs runs on NT4.0, single-threaded. Any input would be greatly appreciated.Is it a valid idea to keep a java socket open for a long time? If so, what
special care do I need to take?Depends.
First why keep it open? Your messages only arrive every couple of seconds, does opening/closing the connection take longer than that?
If you must then the complication you must deal with is that your code must deal with re-establishing the connection when it does fail. Opening/closing it every time avoids that issue. The connection will fail, because computers fail, networks fail and people make mistakes. Which doesn't mean that you shouldn't but merely that you should consider the implications of why you need to keep it open. -
Multiple input stream in one socket connection
Can we have multiple input streams for a java socket connection? It means that in a client/server application (creates using java socket), can we have multiple input streams for the client side program. For example, the input streams are to cater for the need of letting the user to chat and downloading some files from the chat partner at the same time. And do we need to use thread to create the multiple input streams like the case when we create a multithreaded server? Anyone out there who knows the solution please post it. Thanks in advance.
Can we have multiple input streams for a java socket
connection? It means that in a client/server
application (creates using java socket), can we have
multiple input streams for the client side program.
For example, the input streams are to cater for the
need of letting the user to chat and downloading some
files from the chat partner at the same time. And do
we need to use thread to create the multiple input
streams like the case when we create a multithreaded
server? Anyone out there who knows the solution please
post it. Thanks in advance.Ok im no expert here but this is what i learned:
a Socket can have only one InputStream (Socket.getInputStream()) and one OutputStream Socket.getOutputStream()). So you will have to create a way to make multiple Socket connections in your client program. And yes, you have to use threads for your server. if you dont the client will have to wait until the user before them is finished with the connection before being able to connect. I hope this helps you out. BTW please check out http://www.javabible.com. they have the book online now for free.
Joeyford1 -
The service bit "write enable" in Java Socket
Hello,
I am trying to communicate with a third party application and I am having some problems. I use a standard Socket connection, were my application is the Server (ServerSocket). The connection is established, but no data is transmitted.
I talked with the guys behind this third party application, and they said that perhaps their application does not receive a "write enable" service bit of the tcp/ip protocol. I'm not a network wiz, so this is an unknown territory for me.
So I ask you. What is this "write enable" tcp/ip service bit? Is this per default on in java socket connections? If no, how can I change this?
Perhaps this is very basic knowledge, but I've googled a bit and have not found this "service bit".This could refer to something in their
protocol which you aren't implementing correctly.Probably, but I believe they have "forgotten" to mention that it is required in our implementation.
OTOH if you are the server the transaction would
normally begin with a request from the client, not a
write-enablement from the server.The defined protocol smelled fishy when reading the "whitepaper", but we had to accept it (politics). -
Is it wise to keep the socket connection open?
When u have a bunch of HTTP requests coming in to a listener server socket, would it be safe to keep my JAVA socket connection open with KeepAlive or simply open/close at will? I thought of a connection of sockets as well. Thoughts? thx!
It depends which socket your talking about
The serversocket you want to always be open and listened to
the sockets it spawns you should close when you've finished the transaction -
Problem with socket connection through Java Embedding...
We are trying to create a simple socket connection to a socket server through BPEL PM using the Java Embedding component.
BPEL Process : Client makes an asynchronous request. Passes an input variable. The input variable is sent to the Server Program through a socket connection through the Java embedding component.
Server: We are running a simple Socket Server program from command prompt.
The code below works fine as long as we do not try to receive a response from the server (Commented Code).
If we uncomment the code and try to receive a response, it refuses to create an instance for the BPEL Process. And sometimes restarts the BPEL Server.
Client Code:
String msg="NONE";
try{
org.w3c.dom.Element input = (org.w3c.dom.Element) getVariableData("inputVariable","payload","/client:clientProcessRequest/client:input");
msg = input.getNodeValue();
Socket clientsoc=new Socket("ServerIP",1000);
PrintWriter out1=new PrintWriter(clientsoc.getOutputStream());
out1.write(msg);
out1.flush();
BufferedReader cin1=new BufferedReader(new InputStreamReader(clientsoc.getInputStream()));
msg=cin1.readLine();
setVariableData("outputVariable","payload","/client:result",new String(msg));
clientsoc.close();
catch(UnknownHostException e)
System.err.println("Don't know about host: dev.");
System.exit(1);
catch (IOException e)
System.err.println("Couldn't get I/O for "+ "the connection to: dev.");
System.exit(1);
}Repost
-
How to retain socket connection for multiple requests in java 1.3
Hi All,
My problem is to retain client socket connection without opening and closing socket connection for every request.I want to open the socket connection once and send multiple requests one after the other based upon the response over the same socket.Finally I want to close the socket only after completing all my requests and receiving respective responses.I don't want to open and close the socket for each request and response.While at the same time I expect the socket to send each request only after receiving the response for the previous request.
I am using java 1.3 and I am looking for the solution in same version.
Please help me .
Thanx in advance.Look at my response to "Telnet to Unix box from Java"
http://forum.java.sun.com/thread.jsp?forum=31&thread=437231
on "Java Programming" forum. It does exactly that to run the signon and a command. It would be easy to extend it to do multiple commands. -
Socket connection between Java and C
I want to establish socket connection between Java client and C server (on Unix). Can anybody tell how to do it? Will the socket created in client be available in server. I tried out but there was no response from the server.
We too can't connect the daemon server written by "c". The phenomena is below.
<< Execution of this Question1.class >> ---------------------------------------
[kazuyuki@CryptOne tmp]$ java Question1 E 1.2.3.4 MFrame.java 195.211.1.1 15021
<< Output message >> ----------------------------------------------------------
Quetion1 : flg_ = E
Quetion1 : key_ = 1.2.3.4
Quetion1 : fn_ = MFrame.java
Quetion1 : adr_ = CryptOne.localhost/195.211.1.1
Quetion1 : port_ = 15021
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:350)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:137)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:124)
at java.net.Socket.<init>(Socket.java:268)
at java.net.Socket.<init>(Socket.java:122)
at Question1.UPLOAD(Question1.java:65)
at Question1.main(Question1.java:155)
<< Question >> ----------------------------------------------------------------
Why the event "java.net.ConnectException: Connection refused" has occured ?
The server to connect from Question1 can accept the connection request from
the client program coded by "c" program. We have written down the daemon server
program by "c" code tcp/ip socket functions (socket, bind, listen, accept).
Security manager admits the access from this Question1.class, we have checked.
Would you like please answer this Connction refuse occurrence ?
2002.05.18 11:50:00.0(JST)
K.Masuda
<< Java client code>> -------------------------------------------------
(c)Copyright All rights reserved.
K.Masuda 2002.05.18
<< Question1.java >>
import java.lang.String;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.net.Socket;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.net.ConnectException;
import java.net.NoRouteToHostException;
class Question1 {
char flg_;
String key_;
String fn_;
InetAddress adr_;
int port_;
Socket sock_;
Question1(
char flg,
String key,
String fn,
String adr,
int port
flg_ = flg;
key_ = key;
fn_ = fn;
try{
adr_ = InetAddress.getByName( adr );
catch( UnknownHostException e ){
e.printStackTrace();
port_ = port;
System.out.println( "Quetion1 : flg_ = " + flg_ );
System.out.println( "Quetion1 : key_ = " + key_ );
System.out.println( "Quetion1 : fn_ = " + fn_ );
System.out.println( "Quetion1 : adr_ = " + adr_ );
System.out.println( "Quetion1 : port_ = " + port_ );
public void UPLOAD(
try{
sock_ = new Socket( adr_, port_ );
UpLoad();
DnLoad();
sock_.close();
catch( UnknownHostException e ){
e.printStackTrace();
catch( ConnectException e ){
e.printStackTrace();
catch( NoRouteToHostException e ){
e.printStackTrace();
catch( IOException e ){
e.printStackTrace();
public void UpLoad(
byte[] buf = new byte[ 512 ];
int rlen;
int wlen;
try {
OutputStream sos = sock_.getOutputStream();
FileInputStream fis = new FileInputStream( fn_ );
DataInputStream dis = new DataInputStream( fis );
DataOutputStream dos = new DataOutputStream( sos );
while( ( rlen = dis.read( buf, 0, buf.length ) ) >= 0 ){
dos.write( buf, 0, rlen );
dis.close();
dos.close();
fis.close();
sos.close();
catch( IOException e ){
e.printStackTrace();
public void DnLoad(
byte[] buf = new byte[ 512 ];
int rlen;
int wlen;
try {
InputStream sis = sock_.getInputStream();
FileOutputStream fos = new FileOutputStream( fn_ + ".cry" );
DataInputStream dis = new DataInputStream( sis );
DataOutputStream dos = new DataOutputStream( fos );
while( ( rlen = dis.read( buf, 0, buf.length ) ) >= 0 ){
dos.write( buf, 0, rlen );
dis.close();
dos.close();
fos.close();
sis.close();
catch( IOException e ){
e.printStackTrace();
public static void main(
String[] args
char[] chrs = ( new String( args[ 0 ] ) ).toCharArray();
Question1 clnt = new Question1(
// E or D
chrs[ 0 ],
args[ 1 ], // key string
args[ 2 ], // file to be processed
args[ 3 ], // IP address
// port
Integer.parseInt( args[ 4 ] )
clnt.UPLOAD();
} -
Java Socket bind() and connect() method
Hi,
I'm running a windows xp machine and have set it up (using the raspppoe protocol) to make simultaneous dial-up connections to the internet. Each of these dial-up connections then has its own IP address.
When I create a new Socket, bind it to one of these IP addresses and invoke the connect() method (to a remote host), the socket times out. Only when i bind it to the most recent dial-up connection that has been established, the socket connects.
I'm welcome for any ideas :)
thanksIf you'll excuse the lengthy post it has alot of code and outputs :)
Ok Wingate really doesnt have much to do with the program, let me get back to the point and then post the code I have.
Goal of the application:
To use multiple simultaneous dial-up interfaces connected to the internet by binding each of them (using Socket class .bind() method) to its associated Socket object.
Method:
I use the RASPPPOE protocol for Windows XP to allow these multiple simultaneous ADSL dial-up connections. Each of these dial-up instances gets assigned an IP address. I use the NetworkInterface class to retrieve these interfaces/IP addresses and then run a loop to bind each Socket to its associated interface.
The code I am pasting here is over-simplified and is just to illustrate what it is i'm trying to do.
Firstly, this is a cut & paste of the tutorial from the Java website on how to list the Network interfaces on an operating system and the associated output:
import java.io.*;
import java.net.*;
import java.util.*;
import static java.lang.System.out;
public class ListNIFs
public static void main(String args[]) throws SocketException
Enumeration<NetworkInterface> nets = NetworkInterface.getNetworkInterfaces();
for (NetworkInterface netint : Collections.list(nets))
displayInterfaceInformation(netint);
static void displayInterfaceInformation(NetworkInterface netint) throws SocketException {
out.printf("Display name: %s\n", netint.getDisplayName());
out.printf("Name: %s\n", netint.getName());
Enumeration<InetAddress> inetAddresses = netint.getInetAddresses();
for (InetAddress inetAddress : Collections.list(inetAddresses))
out.printf("InetAddress: %s\n", inetAddress);
out.printf("Up? %s\n", netint.isUp());
out.printf("Loopback? %s\n", netint.isLoopback());
out.printf("PointToPoint? %s\n", netint.isPointToPoint());
out.printf("Supports multicast? %s\n", netint.supportsMulticast());
out.printf("Virtual? %s\n", netint.isVirtual());
out.printf("Hardware address: %s\n", Arrays.toString(netint.getHardwareAddress()));
out.printf("MTU: %s\n", netint.getMTU());
out.printf("\n");
}For which the output is:
Display name: MS TCP Loopback interface
Name: lo
InetAddress: /127.0.0.1
Up? true
Loopback? true
PointToPoint? false
Supports multicast? true
Virtual? false
Hardware address: null
MTU: 1520
Display name: Intel(R) PRO/Wireless 3945ABG Network Connection - Packet Scheduler Miniport
Name: eth0
InetAddress: /192.168.1.10
Up? true
Loopback? false
PointToPoint? false
Supports multicast? true
Virtual? false
Hardware address: [0, 25, -46, 93, -13, 86]
MTU: 1500
Display name: WAN (PPP/SLIP) Interface
Name: ppp0
InetAddress: /196.209.42.125
Up? true
Loopback? false
PointToPoint? true
Supports multicast? true
Virtual? false
Hardware address: null
MTU: 1492
Display name: WAN (PPP/SLIP) Interface
Name: ppp1
InetAddress: /196.209.248.25
Up? true
Loopback? false
PointToPoint? true
Supports multicast? true
Virtual? false
Hardware address: null
MTU: 1492
Display name: WAN (PPP/SLIP) Interface
Name: ppp2
InetAddress: /196.209.249.4
Up? true
Loopback? false
PointToPoint? true
Supports multicast? true
Virtual? false
Hardware address: null
MTU: 1492The part to take notice of is the three WAN (PPP/SLIP) Interfaces named ppp0, ppp1 and ppp2. They are simultaneous dial-up connections to the internet, each with a unique IP. I will now attempt to use one of these interfaces to establish a connection to www.google.com on port 80 (purely for illustration).
In the code printed below, I simply hard coded the above listed IP address of the interface for simplification:
import java.net.*;
import java.io.*;
public class SockBind {
private Socket connection;
private void start() throws IOException
while (true)
try {
connection = new Socket();
connection.bind(new InetSocketAddress("196.209.42.125", 12345));
connection.connect(new InetSocketAddress("www.google.com", 80));
connection.close();
} catch (SocketException e) {
System.err.println(e.getMessage());
public static void main(String args[])
try {
SockBind s = new SockBind();
s.start();
System.out.println("Program terminated.");
} catch (IOException e) {
e.printStackTrace();
System.exit(1);
}Once the program reaches the connection.connect() method, it pauses a while until it throws a SocketException with a "timed out" message. I have already tested the dial-up connection (using a wingate, which is irrelevant) just to confirm that the connection is in working order.
EJP if you have any suggestions I will welcome it, many thanks :) -
How to change HttpURLConnection to socket connection in java
hello i have a problem about a socket connection can you help me
i want to change HttpURLConnection connection to socket connection
here is
java.net.URL url = new java.net.URL("http://64.74.75.74/approot/webapp/ZOR/bare");
connection = new sun.net.www.protocol.http.HttpURLConnection(url, " ", 0);
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
java.io.ObjectOutputStream out = new java.io.ObjectOutputStream(connection.getOutputStream());
out.writeObject(getTextFieldGiden().getText());
out.flush();
out.close();
return (String) (new java.io.ObjectInputStream(connection.getInputStream()).readObject());
how can i change it to
socket connection
thank you very muchThe class you mention uses a Socket connection.
If you read the source you will see how it does it.
If you use a debugger yu will see the code which is most relevent. -
Connecting to http web site using java socket
Hi,
Sockets in Java I believe are reusable. Once created, it can be used to send a request using its input stream and get back a response using the output stream. My problem is I am trying to connect to a website using java socket but I am unable to get a response (though the same works fine I use URL and URLConnection). Can anyone tell me whats wrong? Below is the client program:
public class HttpAdapterTest {
public static void main(String[] args) {
try {
Socket socket = new Socket("www.google.com", 80);
BufferedWriter out = new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream()));
out.write("GET /help/basics.html HTTP/1.1");
out.flush();
BufferedReader in = new BufferedReader(
new InputStreamReader(ucon.getInputStream()));
String line = null;
while((line = in.readLine()) != null) {
System.out.println(line);
in.close();
} catch (Exception e) {
e.printStackTrace();
}Look at the JSSE examples. You need to setup a key store, add the jsse jars to your classpath, yadda, yadda, yadda....
-
Is there any way to make a socket connection to a java file on the net?
Is their anyway to make a socket connection to a java applet that I place on a webhost? I want to connect to a javaapplet from my vb.net program and send commands to it. Like http://www.geocities.com/Sylonious/javafile.jpx:7070
?Is their anyway to make a socket connection to a java
applet that I place on a webhost? I want to connect to
a javaapplet from my vb.net program and send commands
to it. Like
http://www.geocities.com/Sylonious/javafile.jpx:7070
?You wouldn't have a port in the url, you would need to have the socket open in the applet code. The vb.net program would also need to be on the same server as the applet or you'll have security issues and I doubt that's possible with geocities. I don't know what you would need to communicate with a vb.net if anything, but I'm sure it's possible. -
Java Chat (Server, Client Socket Connection)
Assignment:
The assignment is to deliver two source codes that can run a Server (1) and Clients (2) in order to create a simpel chat program. The server has to wait and check an IP (localhost) + Port, and the client has to connect to that port and create a socket connection. The only thing that should be done is create a new socket connection for each client... and when a client sends a message, the message should be delivered to all clients connected to the server.
Problem...
However I can read an edit Java, it's difficult for me to write it. I allready found many turturials about socket connections on the internet, and tried to edit those, but they don't really do what I want unless I really write new shit. Is there a way you guys can help me with this, or that you find a really good website that fits my question?According to me ,
take string variable 'str'
Take some class ,I think u already taken.....
Scoket scoket = new Socket(IP,port);
OutputStream out;
IInputStream in;
in = socket.getInputStream();
out = socket.getOutputStream();
If sends the msg then use
out.writeObject(str);
This line sends data to the other user
msg resivce from client then use
str = in.readInput();
& this str set to the any objects out put .
Such as TextField.setText(str);
//Server.class
import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Server extends JFrame
private JTextField enterdField;
private JTextArea displayArea;
private ObjectOutputStream output;
private ObjectInputStream input;
private ServerSocket server;
private Socket connection;
private int counter=1;
public Server()
super("Server");
enterdField = new JTextField();
enterdField.setEditable(false);
enterdField.addActionListener(
new ActionListener()
public void actionPerformed(ActionEvent event)
sendData(event.getActionCommand());
//System.out.println(event.getActionCommand());
enterdField.setText("");
add(enterdField,BorderLayout.NORTH);
displayArea = new JTextArea();
add(new JScrollPane(displayArea),BorderLayout.CENTER);
setSize(300,150);
setVisible(true);
public void runServer()
try
server = new ServerSocket(12345,100);
while(true)
try
waitForConnection();
getStreams();
processConnection();
catch(EOFException eofexception)
displayMessage("\nServer terminated connection");
finally
closeConnection();
counter++;
catch(IOException ioException)
ioException.printStackTrace();
private void waitForConnection() throws IOException
displayMessage("Waiting for connection");
connection = server.accept();
//System.out.println(server.accept());
System.out.println(connection.getInetAddress());//Server Address and Hostname.
displayMessage("Connection"+counter +"received from :"+connection.getInetAddress().getHostName());
private void getStreams() throws IOException
System.out.println("Start getStream");
output = new ObjectOutputStream(connection.getOutputStream());
output.flush();
input = new ObjectInputStream(connection.getInputStream());
displayMessage("\nGot I/O stream\n");
private void processConnection() throws IOException //Read data from Client for Server.
String message="Connection sucessful To Client";
sendData(message);
int i=0;
setTextFieldEditable(true);
do
try
message =(String) input.readObject();//For Client
System.out.println("Input from :"+message);//From Client
displayMessage("\n" + message);
System.out.println("\n" + i++);
catch(ClassNotFoundException classnotfoundexception)
displayMessage("\nUnknown object type recived");
while(!message.equals("CLIENT>>>TERMINATE"));
private void closeConnection()
displayMessage("\nTeminating connection");
setTextFieldEditable(false);
try
output.close();
input.close();
connection.close();
catch(IOException ioException)
ioException.printStackTrace();
private void sendData(String message)//Write data to the Client from the Server.
try
output.writeObject("SERVER>>>"+message);//For Client side.
System.out.println(message);
output.flush();
displayMessage("\nSERVER>>>"+message);//On server side.
catch(IOException ioException)
displayMessage("\nError writing object");
private void displayMessage(final String messageToDisplay)
SwingUtilities.invokeLater(
new Runnable()
public void run()
displayArea.append(messageToDisplay);
private void setTextFieldEditable(final boolean editable)
SwingUtilities.invokeLater(
new Runnable()
public void run()
enterdField.setEditable(editable);
public static void main(String q[])
Server app = new Server();
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
app.runServer();
//Client.class
import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Client extends JFrame
private JTextField enterField;
private JTextArea displayArea;
private ObjectOutputStream output;
private ObjectInputStream input;
private String message="";
private String chatServer;
private Socket client;
public Client (String host)
super("Client");
chatServer=host;
enterField = new JTextField();
enterField.setEditable(false);
enterField.addActionListener(
new ActionListener()
public void actionPerformed(ActionEvent event)
sendData(event.getActionCommand());
enterField.setText("");
add(enterField,BorderLayout.NORTH);
displayArea = new JTextArea();
add(new JScrollPane(displayArea),BorderLayout.CENTER);
setSize(300,150);
setVisible(true);
public void runclient()
try
connectToServer();
getStreams();
processConnection();
catch(EOFException eofException)
displayMessage("\nClient treminated connection");
catch(IOException ioException)
ioException.printStackTrace();
finally
closeConnection();
private void connectToServer() throws IOException
displayMessage("Attempting connection\n");
client = new Socket(InetAddress.getByName(chatServer),12345);
displayMessage("Connect to:"+client.getInetAddress().getHostName());
private void getStreams() throws IOException
output = new ObjectOutputStream(client.getOutputStream());
output.flush();
input = new ObjectInputStream(client.getInputStream());
//Thread t = new Thread(this,"Thread");
//t.start();
displayMessage("\nGot I/O stream\n");
private void processConnection( ) throws IOException
setTextFieldEditable(true);
do
try
message=(String)input.readObject();
displayMessage("\n"+message);
catch(ClassNotFoundException classnotfoundexception)
displayMessage("\nUnknown object type received");
while(!message.equals("SERVER>>>TERMINATE"));
private void closeConnection()
displayMessage("\n Closing connection");
setTextFieldEditable(false);
try
output.close();
input.close();
client.close();
catch(IOException ioException)
ioException.printStackTrace();
private void sendData(String message)
try
output.writeObject("CLIENT>>>"+message);
//System.out.println(message);
output.flush();
displayMessage("\nCLIENT>>>"+message);
catch(IOException ioException)
displayArea.append("\n Error writing object");
private void displayMessage(final String MessageToDisplay)
SwingUtilities.invokeLater(
new Runnable()
public void run()
displayArea.append(MessageToDisplay);
private void setTextFieldEditable(final boolean editable)
SwingUtilities.invokeLater(
new Runnable()
public void run()
enterField.setEditable(editable);
public static void main(String q[])
Client app;
if(q.length==0)
app = new Client("127.0.0.1");
else
app = new Client(q[0]);
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
app.runclient();
Use this example .....
Give me reply.My method is correct or not
All the best -
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http://java.sun.com/j2se/1.5.0/docs/guide/net/enhancements-1.5.0.html
I wonder if any of them are having some effect in the slow connection.
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Here is the list
http://java.sun.com/j2se/1.5.0/docs/guide/net/properties.html
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