Socket remains in "established" state

Question

In the following code, my program listens for input from port 1505. there are 3 PCs to connect to this port. if there is a data from the port there is no problem with thw connection and the sockets are closed and program continues. but when i see one of the computers goes to established state with no data from the port, it does not release the port. although i close sockets and streams in the code, it remains in established state. other computers trying to connect automatically goes to close_wait state and they remain in this state. Please help me solve this problem.
private void makeConnection() throws IOException, ClassNotFoundException, SQLException {
          ServerSocket serverSocket = null;
          Socket clientSocket = null;      
        try {
             serverSocket = new ServerSocket(1505);
        catch(IOException e){
                  System.out.println(" IOException");
                  serverSocket.close();
                  makeConnection();
        try {
              clientSocket = serverSocket.accept();
        } catch (IOException e) {
             System.out.println(" IOException : Accept");
            System.out.println("Accept failed.");
            //System.exit(1);
        BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
        String inputline;
        if((inputline=in.readLine()).equalsIgnoreCase(null)){
     System.out.println(" No Data");
     in.close();
     clientSocket.shutdownInput();
     clientSocket.setTcpNoDelay(true);
     serverSocket.close();
     clientSocket.close();             
             makeConnection();
        else{
             System.out.println(inputline);
             newAnaliz=new AnalizTokenizer2(inputline);
             inputsAndResults.setText(inputline+"\n");
             inputsAndResults.append(newAnaliz.getAnaliz());
             repaint();
             analiz=inputline;
             System.out.println(inputline);
             String analizType=newAnaliz.getAnalizType();
             newSend=new SendAnaliz(analizType, newAnaliz.getUnformattedText(), newAnaliz.getAnaliz());
             int len=newSend.getConnectionStatus().length;
             String[] constat=new String[len];
             constat=newSend.getConnectionStatus();
             setTextArea(constat);           
             in.close();
     //clientSocket.shutdownInput();
     serverSocket.close();
     //clientSocket.setTcpNoDelay(true);
     clientSocket.close();             
             System.out.println("Server Socket Closed"+serverSocket.isClosed());
             //System.gc();
             //new ListenAnaliz();
             //this.dispose();
             makeConnection();
     }

Answer 1

In the following code, my program listens for input
from port 1505. there are 3 PCs to connect to this
port. if there is a data from the port there is no
problem with thw connection and the sockets are
closed and program continues. but when i see one of
the computers goes to established state with no data
from the port, it does not release the port. although
i close sockets and streams in the code, it remains
in established state.You have this back to front. Clearly if the socket is ESTABLISHED nobody has closed it, and it will remain in that state, and your readLine() method will remain blocked, until the client closes the socket.
Other problems:
(a) makeConnection() calls itself endlessly and will eventually run out of stack.
(b) It also closes and reopens the ServerSocket unnecessarily, introducing timing windows during which clients will be unable to connect.
try {
     clientSocket = serverSocket.accept();
} catch (IOException e) {
System.out.println(" IOException :
ception : Accept");
System.out.println("Accept failed.");
//System.exit(1);
}(c) is this really meant to fall through? If you get an IOException here you will get an NPE below.
if((inputline=in.readLine()).equalsIgnoreCase(null)){
(d) How can a null string reference have case?
     in.close();
     clientSocket.shutdownInput();(e) This will do nothing as the socket is already closed by the previous line.
     clientSocket.setTcpNoDelay(true);(f) After the close this throws a SocketException. Clearly you have never executed this line of code.
     serverSocket.close();(g) Bad practice, see above.
     clientSocket.close();(h) Redundant but harmless.
     makeConnection();(i) Infinite recursion, see above.
     in.close();
     //clientSocket.shutdownInput();(j) You were correct to comment this out, it does nothing after the close.
     serverSocket.close();(k) Bad practice, see above.
     //clientSocket.setTcpNoDelay(true);(l) You were correct to comment this out: after the close it throws a SocketException.
     clientSocket.close();(m) Redundant but harmless.
System.out.println("Server Socket Closed"+serverSocket.isClosed());
     //System.gc();
     //new ListenAnaliz();
     //this.dispose();
     makeConnection();(n) Infinite recursion, see above.
Basically you seem to be expecting null from readLine() under the wrong conditions. See what the documentation actually says.
You should also look at some socket coding examples: this is weird.