CODEWITHSUNDEEP
androidmultithreadingfreezeui-thread
Apoorva Somani
Apoorva Somani

Reputation: 515

Starting new Thread freezes UI

I am working on an app that implements a Web Socket server. I am referring this library - https://github.com/TooTallNate/Java-WebSocket

The problem is that the thread holds up the entire UI. Here is the code - 

package com.example.websocket;

import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.util.Collections;

import java.nio.ByteBuffer;

import org.java_websocket.WebSocket;
import org.java_websocket.drafts.Draft;
import org.java_websocket.drafts.Draft_17;
import org.java_websocket.framing.FrameBuilder;
import org.java_websocket.framing.Framedata;
import org.java_websocket.handshake.ClientHandshake;
import org.java_websocket.server.WebSocketServer;

import android.os.Bundle;
import android.provider.Settings.Global;
import android.app.Activity;
import android.content.Context;
import android.view.Menu;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    EditText port, msg;
    Button listener, send;
    TextView status;
    int p;
    int count = 0;
    boolean connect = false;
    boolean listen = false;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        msg = (EditText)findViewById(R.id.editText2);
        listener = (Button)findViewById(R.id.button1);
        send = (Button)findViewById(R.id.button2);
        status = (TextView)findViewById(R.id.textView1);

        listener.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Thread t = new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            SimpleServer server = new SimpleServer();
                            server.start();
                            status.setText("Working inside Thread");
                        } catch (UnknownHostException e) {
                            e.printStackTrace();
                        }
                    }   
                });

                t.start();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public class SimpleServer extends WebSocketServer {

        public SimpleServer() throws UnknownHostException {
            super(new InetSocketAddress(9998));
            // TODO Auto-generated constructor stub
        }

        @Override
        public void onClose(WebSocket arg0, int arg1, String arg2, boolean arg3) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onError(WebSocket arg0, Exception arg1) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onMessage(WebSocket arg0, String arg1) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onOpen(WebSocket arg0, ClientHandshake arg1) {
            status.setText("Working");

        }

    }

}

Upvotes: 0

Views: 1310

Answers (1)

Adam Miśtal
Adam Miśtal

Reputation: 735

You cannot update ui from other threads:

 status.setText("Working inside Thread");

use runOnUiThread method of activity

  runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        status.setText("Working inside Thread");
                    }
                });

By the way youre code cause memory leack and crashes. You cannot start long living operations in activity context. You should run service ,or make this thread in application context, results to ui you can pass by using EventBus.

Upvotes: 1

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