Can not retrieve data from the socket

Question

I am a beginner in developing the java applications. I'm making a chat application on android. I use a thread to serve the client who comes in, but when the client has connected to the server I can not retrieve the data contained in the socket, but when a client connection is lost, data can be displayed. I use the ReadLine method to read data from the socket. This is the program code on the server side:

package server;
import java.net.*;
import java.io.*;
import java.util.Vector;  

import com.sun.org.apache.bcel.internal.generic.NEW;  

public class Server {       

public static void main(String[] args)throws IOException, InstantiationException,
IllegalAccessException {            

    ServerSocket servsocket = null;  
    Socket sock = null;  
    byte[] bytebuffer = new byte[512];  

    try {
        System.out.println("SERVER IS RUNNING...");
        servsocket = new ServerSocket(28000);
        while(true){
        sock = servsocket.accept();
        System.out.println(servsocket.isBound());
        System.out.println("Port "+servsocket+" Ready!!!");
        System.out.println("Accept connection requests from " + sock);
        System.out.println("From CLIENT "+sock.getInetAddress()+ " and PORT " +  
            sock.getPort());
        ChatThread thread = new ChatThread(sock);  
        System.out.println("Thread is running");
        thread.run();       


        }
    } catch (IOException ioe) {
        System.out.println(ioe);
    } 
    finally{
            try {
                servsocket.close();
                } catch (IOException ioe) {
                    System.out.println(ioe);
                }
            }       
    }
    } 

class ChatThread extends Thread{
    static Vector<ChatThread> chatthread = new Vector<ChatThread>(10);
    private Socket sock;
    private BufferedReader in ;
    private PrintWriter out;

    public ChatThread (Socket socket) throws IOException {
        this.sock = socket;
        in = new BufferedReader(
                new InputStreamReader(socket.getInputStream()));
        out = new PrintWriter(
                new OutputStreamWriter(socket.getOutputStream()));

        byte[] bytebuffer = new byte[512];
        int receivemssg;

    }

    public void run(){
        int recvMsgSize;
        byte[] bytebuffer = new byte[512];
        String readsocket;
        try {
            readsocket = in.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
            }
                }   

Below the display on the server side when the program starts. I tried to send the word "Hello ...." from the client side. Can be seen that the thread is not running.

Server is running... true Port ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=28000] Ready!!! Accept connection requests fromSocket[addr=/172.17.231.254,port=3567,localport=28000] From CLIENT /172.17.231.254 and PORT 3567 Thread is Running...

When I replace the readline method on a thread with getInputStream the thread can be run from the client and the message can be displayed. This is the code that I enter the thread to replace the readline method that I used before.

public ChatThread (Socket socket) throws IOException {
        this.sock = socket;
        in  = sock.getInputStream();
        out = sock.getOutputStream();
        byte[] bytebuffer = new byte[512];
        int receivemssg;

    }

    public void run(){
        int recvMsgSize;
        byte[] bytebuffer = new byte[512];

        System.out.println("Thread is Running...");
        String masuk = new String(bytebuffer);

        System.out.println(bytebuffer);
        System.out.println(in.toString());
        System.out.println("thread successfully executed !!!");

        synchronized (chatthread) {
            chatthread.addElement(this);
        }

         try {
            while ((recvMsgSize = in.read(bytebuffer)) != -1) {
                    out.write(bytebuffer, 0, recvMsgSize);
                    System.out.println("The length of a character is received and returned "+bytebuffer.length);
                 }
        } catch (IOException e) {

            System.out.println(e);
        }
                    }
                    }

but the next problem is I can not bring up the contents of a socket in a string / text that appears is as follows:

Port ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=28000] Siap!!! Accept connection requests fromSocket[addr=/172.17.231.254,port=3577,localport=28000] From CLIENT /172.17.231.254 and PORT 3577 Thread is Running... [B@7c6768 java.net.SocketInputStream@1690726 thread successfully executed !!! The length of a character is received and returned 512

Please Help me, thanks :) GBU guys...

Answer 1

See the developer docmentation

public final String readLine () Since: API Level 1

Returns a string containing the next line of text available from this stream. A line is made of zero or more characters followed by '\n', '\r', "\r\n" or the end of the stream. The string does not include the newline sequence.

readLine() will block and not return until it either sees an end-of-line condition such as a newline character, or the end of the stream is reached, which is probably what happens when the connection is lost.

If you want to use readLine() you need to send "Hello....\n" or otherwise append a terminating character for readLine() to see.