Socket and PORT problem

I am new to socket programming. Is there a command in UNIX to see which ports are not occupied?
Since I have problem right now in my program to close the sockets, will they be closed automatically after I interrupt the program, should I close it manually from the command line?
TIA.
mmc

When you create a Socket, you can either bind to port 0 (which binds to the first available port) or to any other valid Port number. There is no Java-based method for geting the port numbers in-use or available. When your program terminates, the sockets will terminate as well, but the port may not be available for use for a few seconds. This allows for the system to be reset.

Similar Messages

Chatserver socket and port problem

hi,all.
i write a chat server use java socket. now is more than 2000 users connect to my server. but too many user make the chat message speed slow. now my server is open one port to listen the client connection. who can tell me if i change my server to open multi port to listen the client connection will rather than open one port. or it is same effect.
please give me some advice. thanks.
my homepage is:http://www.easyfad.com

my server system resource is no problem. Have you timed the bus on your machine?
18% of memory means physical or total. If total is that 18% hitting the hard drive?
What is your actual network speed? A 100m ethernet has a theoretical speed of about 12 meg per second, in practice you will never get even close to that. A normal ftp transfer might only get 500k per second. And networks can be significantly overloaded.
What are the configuration parameters for your IP stack? It might be configured incorrectly for the type of traffic and quality of traffic that you are getting.
The above are all possible things that can affect performance. And there are probably more. Standard OS tools are NOT the best way to measure platform performance. They can often provide misleading numbers, even when one knows what the numbers really mean.
if i use multi port to create socket connection,
if it will help to increase message sending speed ? Like I said I can't see how. Something is causing a slowdown. Your NIC can only process so much traffic. If your NIC was the bottle neck and you had two NICs then that would help. But if it was me I really wouldn't try a two NIC solution until I had exhausted every other possibility. First because it is unlikely to the be bottleneck and two because setting up a 2 NIC (or more) server is not plug and go solution.

About socket and port problem

hi,all.
i write a chat server use java socket. now is more than 2000 users connect to my server. but too many user make the chat message speed slow. now my server is open one port to listen the client connection. who can tell me if i change my server to open multi port to listen the client connection will rather than open one port. or it is same effect.
please give me some advice. thanks.

Maybe your machine is not strong enough to serve that many users at a time anyway. In that case using several ports won't help.

Sockets and ports - routing messages between machines? helpppp!

Hi,
I'm new to java and am hoping someone out there can help me, hoping this is an ok place to post this:
If all you need to create a connection is an IP address and a port number, using streams...
Can you route messages from A to B then from B to C, where A looks up C through B having a hash table which contains C's IP address and port number?
And how in the first instance does B know about A's IP address? All the examples I've seen the IP address is hard coded?
Thanks in advance!

I'm not sure what you are really trying to do... Can you explain in more concrete terms? Are you writing a chat client + server or something like that?

Whats socket and port ??

Hi,
iam new to sockets...
i dont know whats the difference between sockets and ports

http://java.sun.com/docs/books/tutorial/networking/sockets/definition.html

Sockets and ports - how to route through another machine?

Hi,
I'm hoping someone out there can help me:
If all you need to create a connection is an IP address and a port number, using streams...
Can you route messages from A to B then from B to C, where A looks up C through B having a hash table which contains C's IP address and port number?
And how in the first instance does B know about A's IP address? All the examples I've seen the IP address is hard coded?
Thanks in advance!

Ok, so i mean I know this is possible, but I have some users who need to communicate with each other, sorta a message passing approach but with TCP rather than using JMS (time to do this in is v limited).
They need to talk to a middle computer, whos job it is to lookup an appropriate partner to talk to, but:
how do i go about getting the IP address in the first place so that they know who to talk to?
Before communication can take place does there have to be some agreement in which they exchange IP addresses and port numbers?

Smtp and port problems--cant use email

Using OSX 10.4.9, Total Access 2003 1.0
Oct 19 was the last email received through Mac mail. Using Earthlink.net for email. Contacted Earthlink several times, as there was a problem with "Cannot send message using the server smtpauth.earthlink.net" There was a problem with port 25, so i switched to port 587. There is still a problem, and Earthlink now says that it is an Apple problem, not an Earthlink problem
I upgraded to Tiger early summer, and have had no problems, until Oct 19, when it just stopped.
I am very frustrated and want to use MacMail instead of Earthlink's WebMail. I need to know how to fix it,

Hello, mnkeen.
This post may repeat things you have already tried, but I am replying just in case. In addition, I hope I am reading your message correctly.
One of my mail providers is Earthlink; however, I do not use TotalAccess.
• Go to www.earthlink.net
• Click on Support at the top of the page.
• Under Top Solutions select "Setting Up Your Email Program."
• Special Note: You are not going to set up an email program; you are just using the article for research.
• Scroll down to Setting Up Another Mail Client for EarthLink Access and select Mac OS X Mail 1.4.
1. Get the server settings if you need them.
23. through 31. Compare the pictures with your settings.
29. As you write that you have already set the Server Port to 587, I am wondering if the snag you are experiencing is in the selection of the Authentication option.
For what it is worth, my home network uses MD 5 Challenge-Response.
Other things to check:
• Under Top Solutions you may also want to select "Troubleshooting Email Problems."
• Maybe the links to "Configuring your email for SMTP Authentication (This is now required for Earthlink email accounts)" and / or "Changing email settings" might be of use to you.
• Both of those articles include specific information and pictures for Mac OS X Mail.
Sincerely,
No Alibi.

Socket and multithreading problem (flow control)

This code is heavily influenced by the KKMultiServerThread. I am having problems controlling the thread flow.
             login = new MultiServerThreadLogin(serverSocket.accept(), serverSocket);
        login.start();
          while(true){
             System.out.println(login.getAuthen());
             while(login.getAuthen()){
                  System.out.println("doing hello");
                  hello = new KKMultiServerThread(serverSocket.accept(), serverSocket);
                  hello.start();
                  if(hello.getFlag())
                  break;
          }here, you can see that i am trying to start a thread to login the user and then recieve files from the cilent. When my GUI runs, there is no problem whatsoever that is for the 1st time, however when i try running the 2nd time, the code as u can see, doesnt allow that... so is there anyway to break away from the inner loop?

hey thanks for replying... i'm sorry but in a rush here...
this snippet resides in the server. There are 2 classes, namely MultiServerLoginThread and KKMultiServerThread, both extends Thread.
The function of the MultiServerLoginThread is to read in bytes of Secretkey, username(encrypted) and password(encrypted). This should only take place once.
The function of theother thread, KKMultiServerThread is to read in the file name to be transferred and the contents. This is based on the KKMultiServerThread which can be found somewhere in this forum... i hope...
The KKMultiServerThread is started over and over because the client is sending multiple files. Hence the while loop. However after sending the last file, it should go to the MultiServerLoginThread....
One thing i don't really get it is that if i were to do this(put the creation of the login thread within the while loop):
while(true){
             System.out.println(login.getAuthen());
             login = new MultiServerThreadLogin(serverSocket.accept(), serverSocket);
        login.start();
             while(login.getAuthen()){
                  System.out.println("doing hello");
                  hello = new KKMultiServerThread(serverSocket.accept(), serverSocket);
                  hello.start();
                  if(hello.getFlag())
                  break;
          }The GUI totally hangs.
More explanation...
hello.getFlag() returns the flag when the client has finished sending all the files
login.getAuthen() returns whether the user has successfully logged in with correct creditials

Sockets and Ports and DataInputStreams

I think this is just a basic TCP/IP networking question: When I open a socket connection to a remote ip address/port, what port am i receiving data on via my DataInputStream? Is it the same port I opened the remote connection on, 80, or what?
thanks,
Abraham

int answer = yourSocket.getLocalPort();

Socket and Thread Problem

When reading an Inputstream received after a connection has been established (throught a Socke connect) between a Server ands a Client , messages are being lost when a wait method is call. A client sents message which have to be processed and response sent back to the client . The message are encoded and as the code below shows each message ends with a '":" .Not only one message is sent at a time. and when messages are sent the client sometimes expect replies. This means that when a message is read , it be being processed by a Processor and until the reply has be sent this the thread reading the messages has to wait. when a reply is sent and the thread is waken up, the remaining the messages in the Input stream gets lost but the loop is not also exited since the end of the file is never reached.
Solution:
1. read a command message. if you find end of message, process the message and wait until you are notify and continue with the next command line
public class Sender extends Thread {
     private Socket socket;
     private Processor processor = newProcessor();
     private boolean DEBUG = false;
     public Sender (Socket socket) {
          super();
          this.socket = socket;
          start();
     public void run() {
          while (true) {
               if (processor .getStateOfProcess()&& socket != null) {
                    InputStream input = null;
                    try {
                         input = socket.getInputStream();
                         if (processor .dispatchMessage() != null) {
                              socket.getOutputStream().write(
                                        CacheManager.dispatchMessage());
                              processor .ClearMessage();
                    } catch (IOException ex) {
                    int i = 0;
                    char oldChar = ' ';
                    char c = ' ';
                    StringBuffer buffer = new StringBuffer();
                    try {
                         while ((i = input .read()) != -1) {
                              c = (char) i;
                              buffer.append(c);
                                                if (c == ':' && oldChar != '\\') {
                                   processor .process(buffer.toString());
                                   buffer = new StringBuffer();
                                   c = ' ';
                                                          try {
                                        synchronized (this) {
                                             wait();
                                   } catch (InterruptedException e1) {
                                                   if (processor.dispatchMessage() != null) {
                                        socket.getOutputStream().write(
                                                  CacheManager.dispatchMessage());
                                        processor.ClearMessage();
                              oldChar = c;
                                } catch (IOException e) {
   public void wakeup() {
          synchronized (this) {
               notify();
} This thread leaves that wait when the wakeup method is called in the Processor class.
Question
can some one help me figure out way and where the messages are being lost after the first message has been processed. why can the other message not be seen even other messages are still sent.
What can be a possible solution
thanks

I didn't follow all of that, but I can see one serious error in your concurrent. You should always test the condition you're waiting for inside the synchronized block - otherwise you can't be certain that wait() is called before the corresponding notify() / notifyAll() call.

Problem with socket and object writing

Hi,
I programm this client/server app, the client has a point (graphic ) , the server has a point and when the mouse is moving it moves the point and the new position is send via the socket.
The probleme is that i don't receive the good thing.
When i display the coord of the point before sending it's good , but when receiving from the socket the coords are always the same ...
i don't understand .
Well , try and tell me ...
Thx.

oups, the program can be usefull ...
import java.applet.*;
import java.awt.*;
import java.util.*;
import java.awt.event.*;
public class server_JFrame extends javax.swing.JFrame implements MouseListener,MouseMotionListener{
point p1,p2;
server s;
public server_JFrame()
this.setSize(600,400);
addMouseListener(this);
addMouseMotionListener(this);
p2=new point(50,50,new Color(0,0,255));
p1=new point(200,200,new Color(255,0,0));
s = new server(p2,this);
public void paint(Graphics g)
super.paint(g);
g.setColor(p1.get_color());
g.fillOval(p1.get_x(), p1.get_y(),10,10);
g.setColor(p2.get_color());
g.fillOval(p2.get_x(), p2.get_y(),10,10);
public void mouseClicked(MouseEvent e) { }
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {}
public void mouseMoved(MouseEvent e)
p1.set_x(e.getX());
p1.set_y(e.getY());
s.write_point(p1);
repaint();
public static void main(String args[])
     server_JFrame sjf = new server_JFrame();
sjf.setDefaultCloseOperation(EXIT_ON_CLOSE);
     sjf.setTitle("server");
sjf.show();
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
public class server {
point p_;
Container c_;
ObjectInputStream Istream_;
ObjectOutputStream Ostream_;
public server(point p,Container c)
p_=p;
c_=c;
try
ServerSocket server = new java.net.ServerSocket(80);
System.out.println("attente d'un client");
java.net.Socket client = server.accept();
System.out.println("client accept�");
Istream_ = new ObjectInputStream(client.getInputStream());
Ostream_ = new ObjectOutputStream(client.getOutputStream());
ThreadRead tr = new ThreadRead(Istream_,p_,c_);
catch (Exception exception) { exception.printStackTrace(); }
public void write_point(point p)
try
System.out.print("x="+p.get_x());
System.out.println(" y="+p.get_y());
Ostream_.flush();
Ostream_.writeObject(p);
Ostream_.flush();
catch (Exception exception) {exception.printStackTrace();}
import java.applet.*;
import java.awt.*;
import java.util.*;
import java.awt.event.*;
public class client_JFrame extends javax.swing.JFrame implements MouseListener,MouseMotionListener{
point p1,p2;
client c;
public client_JFrame()
this.setSize(600,400);
addMouseListener(this);
addMouseMotionListener(this);
p1=new point(50,50,new Color(0,0,255));
p2=new point(200,200,new Color(255,0,0));
c = new client(p2,this);
public void paint(Graphics g)
super.paint(g);
g.setColor(p1.get_color());
g.fillOval(p1.get_x(), p1.get_y(),10,10);
g.setColor(p2.get_color());
g.fillOval(p2.get_x(), p2.get_y(),10,10);
public void mouseClicked(MouseEvent e) { }
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {}
public void mouseMoved(MouseEvent e)
p1.set_x(e.getX());
p1.set_y(e.getY());
c.write_point(p1);
repaint();
public static void main(String args[])
     client_JFrame cjf = new client_JFrame();
cjf.setDefaultCloseOperation(EXIT_ON_CLOSE);
     cjf.setTitle("client");
cjf.show();
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
public class client {
point p_;
Container c_;
ObjectInputStream Istream_;
ObjectOutputStream Ostream_;
public client(point p,Container c)
p_=p;
c_=c;
try
ipJDialog ipjd = new ipJDialog();
String ip = ipjd.getvalue();
Socket socket = new Socket(ip,80);
System.out.println("connection avec serveur reussi");
Ostream_ = new ObjectOutputStream(socket.getOutputStream());
Istream_ = new ObjectInputStream(socket.getInputStream());
ThreadRead tr = new ThreadRead(Istream_,p_,c_);
catch (Exception exception) {*exception.printStackTrace();*/System.out.println("connection avec serveur echou�");}
public void write_point(point p)
try
System.out.print("x="+p.get_x());
System.out.println(" y="+p.get_y());
Ostream_.flush();
Ostream_.writeObject(p);
Ostream_.flush();
catch (Exception exception) {exception.printStackTrace();}
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
public class client {
point p_;
Container c_;
ObjectInputStream Istream_;
ObjectOutputStream Ostream_;
public client(point p,Container c)
p_=p;
c_=c;
try
ipJDialog ipjd = new ipJDialog();
String ip = ipjd.getvalue();
Socket socket = new Socket(ip,80);
System.out.println("connection avec serveur reussi");
Ostream_ = new ObjectOutputStream(socket.getOutputStream());
Istream_ = new ObjectInputStream(socket.getInputStream());
ThreadRead tr = new ThreadRead(Istream_,p_,c_);
catch (Exception exception) {*exception.printStackTrace();*/System.out.println("connection avec serveur echou�");}
public void write_point(point p)
try
System.out.print("x="+p.get_x());
System.out.println(" y="+p.get_y());
Ostream_.flush();
Ostream_.writeObject(p);
Ostream_.flush();
catch (Exception exception) {exception.printStackTrace();}
import java.io.Serializable;
import java.awt.*;
public class point implements Serializable{
private int x_;
private int y_;
private Color c_;
public point(int x, int y, Color c) {
x_=x;
y_=y;
c_=c;
public int get_x() { return x_ ; }
public int get_y() { return y_ ; }
public void set_x(int x) { x_=x ; }
public void set_y(int y) { y_=y ; }
public Color get_color() { return c_ ; }
}

Xbox 360/one problem and port forwarding

For a couple months now (since I got my AirPort Extreme) I have not been able to connect to a certain friend on xbox. I can connect to anybody else however. The only way we can (kind of) connect is if somebody else is host and we both connect to him.
My NAT type is Moderate. When I try to test my connection on my xbox it says that I can connect but I am limited in matchmaking (this is joining games and using voice chat, which is the problem named above for my particular friend). The xbox shows the error and suggests that I enable UPnP or open the port 3074.
The problem is that I have already have! I gave my xbox a static IP and forwarded the port 3074 to that IP.
(I have also tried forwarding all the ports that xbox live uses to the xbox. These being:
Port 88 (UDP)
Port 3074 (UDP and TCP)
Port 53 (UDP and TCP)
Port 80 (TCP)
as found on the xbox website... https://support.xbox.com/en-US/xbox-360/networking/network-ports-used-xbox-live
I made sure to put them in the right text boxes for UDP and TCP so that is not the problem either.)
I know that the AirPort Extreme does not support UPnP but does have a similar thing called NAT Port Mapping Protocol which was already enabled. (I tried all possibilities of enabling/disabling NAT...Protocol and port forwarding/not port forwarding.) --- This is not the solution as I see it
In short: My xbox tells me to open port 3074. I already have. It still tells me to open it and still won't work.
I posted this on the apple discussion page (instead of the xbox discussion page) because I know that it's not an xbox problem. When I had my old linksys router it worked perfectly.

I have this exact same question and problem. I know this doesn't help, but would appreciate any updated information if you find an answer. I'll keep working on this also and let you know if I find an anwer.

Web service invocation problem on host hostname and port 8000 protocol : http logical port name : LP_WS_SMDAGENT_MONITORING

hello colleagues,
In the phase Connect Diagnostics dont show the Agent available in SLD, but when go to SLD i have the agents,
Error,
Connect Diagnostics Agent
The table does not contain any data
Agent availables in all SLD
SOAP:1.007 SRT: Unupported xstream found: ("HTTP Code 401 : Unauthorized")
Web service invocation problem on host hostname and port 8000 protocol : http logical port name : LP_WS_SMDAGENT_MONITORING
Thanks

OK, then pls follow below steps;
- Go to step 'Create Users' in solman_setup System Preparation scenario and make sure the user SM_INTERN_WS has a green status. Use the 'Test Login' button to make sure the user is not locked and has correct credentials maintained in solman_setup
- Immediately after checking the user status, navigate to Configure Connectivity->Enable Web Services and execute again the 'Create Logical Ports' automatic activity, in order to propagate the correct credentials to the Logical Port definitions.
- If the above operation is not successful, repeat the two steps above, providing a different user Id in 'Create Users' step, eg SM_INTERN_W1. This will prevent situations where the user gets locked by Logical Ports using an obsolete password.
Let me know the results.
Regards,
Vivek

Problem with the socket and the standard output stream

Hy, I have a little problem with a socket program. It has the server and the client. The problem is that the client at one point in the program, cannot print messages in the console.
My program does the next: the server waits connections, when a client connects to it, the server gets outputstream to the socket and writes two strings on it. Meanwhile, the client gets the inputstream to the socket and reads on it with a loop the two strings written by the server . The strings are printed by the client in the console. The problem starts here; once the read strings are printed ,I mean, after the loop, there are other System.out.println in the client but the console doesnt print anything . It curious that only when I comment on the server code the line that says: "br.readLine()" just before the catch, the client prints all the System.out.println after the loop but why?
Here is the code:
Server code:
public class MyServerSocket {
public MyServerSocket() {
try{
ServerSocket server= new ServerSocket(2000);
System.out.println("servidor iniciado");
Socket client=server.accept();
System.out.println("Client connected");
OutputStream os=client.getOutputStream();
PrintWriter pw= new PrintWriter(os);
String cadena1="cadena1";
String cadena2="cadena2";
pw.println(cadena1);
pw.println(cadena2);
pw.flush();
InputStream is=client.getInputStream();
InputStreamReader isr= new InputStreamReader(is);
BufferedReader br= new BufferedReader(isr);
br.readLine(); //If a comment this line, the client prints after the loop, all the System.out....
catch (IOException e) {
// TODO: handle exception
public static void main(String[] args) {
new MyServerSocket
Client code:
public class MyClientSocket {
public MyClientSocket () {
try{
Socket client= new Socket("localhost",2000);
InputStream is=client.getInputStream();
InputStreamReader isr= new InputStreamReader(is);
BufferedReader br= new BufferedReader(isr);
String read;
while((read=br.readLine())!=null){
System.out.println(read);
//These messages are not printed unless I comment the line I talked about in the server code
System.out.println("leido");
System.out.println("hola");
}catch (IOException e) {
public static void main(String[] args) {
new MyClientSocket
}

You are right but with this program the loop ends. As you see, the first class, the Server, writes to the socket one text file. The second class, the client, reads the text file in his socket written by the server and writes it to a file in his machine.
NOTE: The loop in the client ends and the server doesnt make any close() socket or shutdownOutput() .
public class ServidorSocketFicheromio {
     public ServidorSocketFicheromio() {
try{
     ServerSocket servidor= new ServerSocket(2000);
     System.out.println("servidor iniciado");
     Socket cliente=servidor.accept();
     System.out.println("cliente conectado");
     OutputStream os=cliente.getOutputStream();
     PrintWriter pw= new PrintWriter(os);
     File f = new File("c:\\curso java\\DUDAS.TXT");
     FileReader fr= new FileReader(f);
     BufferedReader br= new BufferedReader(fr);
     String leido;
     while((leido=br.readLine())!=null){
          pw.println(leido);
     pw.flush();
     }catch (IOException e) {
     * @param args
     public static void main(String[] args) {
          new ServidorSocketFicheromio();
public class ClienteSocketFicheromio {
     public ClienteSocketFicheromio() {
try{
     Socket cliente= new Socket("localhost",2000);
     File f = new File("G:\\pepe.txt");
     FileWriter fw= new FileWriter(f);
     PrintWriter pw= new PrintWriter(fw);
     InputStream is=cliente.getInputStream();
     InputStreamReader isr= new InputStreamReader(is);
     BufferedReader br= new BufferedReader(isr);
     String leido;
     while((leido=br.readLine())!=null){
          pw.println(leido);
          System.out.println(leido);
          System.out.println("leido");
          System.out.println("hola");
          pw.flush();
     }catch (IOException e) {
     public static void main(String[] args) {
     new ClienteSocketFicheromio();/
}

BPM Worklist Problem After Setting Frontend Host and Port

Hi all,
I was following the EDG for SOA 11.1.1.5 and was encountering a problem with the BPM Worklist after setting the Frontend Host and Port. We have a topology that includes a load balancer that terminates SSL, two OHS instances, and two SOA instances on separate VMs. When BPM Worklist was loading, it was calling webservices internally through the load balancer, but WebLogic was expecting them as http://. It was not able to resolve the HTTPS port that was being sent from the load balancer through the 80 to 443 redirect.
What the current EDG does not tell you, is that you have to also turn on "Enable Weblogic Plug-In" for WebLogic to use the OHS plug-in. I did it at the domain level, as all traffic will go through the load balancer. This essentially tells WebLogic that all URLs are https://
Here is an exerpt from the SOA.out log file:
<Sep 8, 2011 9:32:06 PM PDT> <Error> <oracle.soa.services.workflow.worklist> <BEA-000000> <<.> Service error.
Internal Error; Service error occurs in IdentityService in method lookupUser.
Refer to the log file that is configured for oracle.soa.services.identity for more details on this error and contact Oracle Support Services
ORABPEL-10585
Service error.
Internal Error; Service error occurs in IdentityService in method lookupUser.
Refer to the log file that is configured for oracle.soa.services.identity for more details on this error and contact Oracle Support Services
Caused By: javax.xml.soap.SOAPException: oracle.j2ee.ws.saaj.ContentTypeException: Not a valid SOAP Content-Type: text/html; charset=UTF-8
What it is also missing, is that you should also set the SOA Infrastructure ServerURL mbean for the load balancer, to match the frontend host and port. Do this through Fusion Middleware Contol. Otherwise, you could encounter URL mismatches.
I hope this helps someone else.
I've asked Oracle to add this to the EDG for SOA. It's in the IDM guide, but not in any other EDGs.

Thanks Josh. It helped me infact in 11.1.1.4 Enable Weblogic Plug-In is not required. But 11.1.1.5 I thing it is mandatory. Oracle should have a clear documentaion.

Socket and PORT problem

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