Question

This is in my client:

public static void logIn(String name, String pass) {
try {
    Socket s = new Socket("localhost", 9000);
    PrintStream out = new PrintStream(s.getOutputStream());
    BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
    out.print(name + "," + pass);
    out.flush();
    out.close();

    System.out.println(in.readLine());

    in.close();
    s.close();
}
catch(UnknownHostException exp)
{
    exp.printStackTrace();

}
catch(java.io.IOException exp)
{
    exp.printStackTrace();
}   
}

and this I have in my server:

 public static void main(String[] args){
 boolean clientExists=false;
 ArrayList<User> users = new ArrayList<User>();
 users.add(new User("jmeno","heslo"));
 ServerSocket ss;
 try {
    ss = new ServerSocket(9000);
    while(true) {
                clientExists=false;
        Socket s = ss.accept();
        BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
        PrintStream out = new PrintStream(s.getOutputStream());
        String xmlpacket="";
                String pom;

                while ((pom = in.readLine())!=null){
                     xmlpacket+=pom;
                     xmlpacket+="\n";
                }

                for(User us: users)
                    {
                            if(us.isUserNameAndPasswordRight(login, passwd))
                            {
                                    out.print("user is connected");
                                    out.flush();
                                    clientExists=true;
                            }
                    }
                }
                if(clientExist != true)
              out.print("bad login");
        out.flush();
        out.close();
        in.close();
        s.close();
}
catch(java.io.IOException exp)
{
    System.out.println("chyba u socketu!");
}

}

Is it posible to working like that? I can´t get this working because exception on client side when try reading from server the answer.

Edit:
This is stacktrace:

java.net.SocketException: socket closed
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at java.io.BufferedReader.fill(Unknown Source)
    at java.io.BufferedReader.readLine(Unknown Source)
    at java.io.BufferedReader.readLine(Unknown Source)
    at client.client.logIn(client.java:79)


    at client.GUI.GUI.jMenuItem1ActionPerformed(GUI.java:379)
    at client.GUI.GUI.access$5(GUI.java:367)
    at client.GUI.GUI$5.actionPerformed(GUI.java:151)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.AbstractButton.doClick(Unknown Source)
    at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
    at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$000(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

I did several things, so give all the code.

• Placed the buffered reader later, to possibly prevent blocking.
• Added encoding, so it does not use default OS encoding (client on different OS).
• Did println i.o. print.
• Autoflushing.
• Inportant: no PrintStream but PrintWriter.

• No loop on xmlpacket; that was code for later.

  public static void logIn(String name, String pass) {
  try {
      Socket s = new Socket("localhost", 9000);
      //PrintStream out = new PrintStream(s.getOutputStream(), true, "UTF-8");
      PrintWriter out = new PrintWriter(new OutputStreamWriter(s.getOutputStream(), "UTF-8"), true);
      out.println(name + "," + pass);
      out.flush();
  
      BufferedReader in = new BufferedReader(new InputStreamReader(
              s.getInputStream(), "UTF-8"));
  
      System.out.println(in.readLine());
  
      out.close();
      in.close();
      s.close();
  } catch (UnknownHostException exp) {
      exp.printStackTrace();
  
  } catch (java.io.IOException exp) {
      exp.printStackTrace();
  }
  }
  
  
  public static void main(String[] args) {
  ArrayList<User> users = new ArrayList<User>();
  users.add(new User("jmeno", "heslo"));
  ServerSocket ss;
  try {
      ss = new ServerSocket(9000);
      while (true) {
          Socket s = ss.accept();
          System.out.println("Accept...");
          BufferedReader in = new BufferedReader(new InputStreamReader(
                  s.getInputStream(), "UTF-8"));
          PrintWriter out = new PrintWriter(new OutputStreamWriter(s.getOutputStream(), "UTF-8"), true);
          String xmlpacket = "";
          String pom;
  
          pom = in.readLine();
          //while ((pom = in.readLine()) != null) {
              xmlpacket += pom;
              xmlpacket += "\n";
          //}
          int commaPos = xmlpacket.indexOf(',');
          int newlinePos = xmlpacket.indexOf('\n');
          String login = xmlpacket.substring(0, commaPos);
          String passwd = xmlpacket.substring(commaPos + 1, newlinePos);                        
  
          boolean clientExists = false;
          for (User us : users) {
              if (us.isUserNameAndPasswordRight(login, passwd)) {
                  out.println("user is connected");
                  clientExists = true;
                  break;
              }
          }
          if (!clientExists)
              out.println("bad login");
          out.close();
          in.close();
          s.close();
      }
  } catch (java.io.IOException exp) {
      System.out.println("chyba u socketu!");
  }
  }