Simple Android Chat Application, client side.

It's client side of Simple Android Chat Application, for the server side, refer last post "Implement simple Android Chat Application, server side".


MainActivity.java

package com.example.androidchatclient;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {
 
 static final int SocketServerPORT = 8080;
 
 LinearLayout loginPanel, chatPanel;

 EditText editTextUserName, editTextAddress;
 Button buttonConnect;
 TextView chatMsg, textPort;
 
 EditText editTextSay;
 Button buttonSend;
 Button buttonDisconnect;

 String msgLog = "";
 
 ChatClientThread chatClientThread = null;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  loginPanel = (LinearLayout)findViewById(R.id.loginpanel);
  chatPanel = (LinearLayout)findViewById(R.id.chatpanel);

  editTextUserName = (EditText) findViewById(R.id.username);
  editTextAddress = (EditText) findViewById(R.id.address);
  textPort = (TextView) findViewById(R.id.port);
  textPort.setText("port: " + SocketServerPORT);
  buttonConnect = (Button) findViewById(R.id.connect);
  buttonDisconnect = (Button) findViewById(R.id.disconnect);
  chatMsg = (TextView) findViewById(R.id.chatmsg);

  buttonConnect.setOnClickListener(buttonConnectOnClickListener);
  buttonDisconnect.setOnClickListener(buttonDisconnectOnClickListener);
  
  editTextSay = (EditText)findViewById(R.id.say);
  buttonSend = (Button)findViewById(R.id.send);
  
  buttonSend.setOnClickListener(buttonSendOnClickListener);
 }
 
 OnClickListener buttonDisconnectOnClickListener = new OnClickListener() {

  @Override
  public void onClick(View v) {
   if(chatClientThread==null){
    return;
   }
   chatClientThread.disconnect();
  }
  
 };
 
 OnClickListener buttonSendOnClickListener = new OnClickListener() {

  @Override
  public void onClick(View v) {
   if (editTextSay.getText().toString().equals("")) {
    return;
   }
   
   if(chatClientThread==null){
    return;
   }
   
   chatClientThread.sendMsg(editTextSay.getText().toString() + "\n");
  }
  
 };

 OnClickListener buttonConnectOnClickListener = new OnClickListener() {

  @Override
  public void onClick(View v) {
   String textUserName = editTextUserName.getText().toString();
   if (textUserName.equals("")) {
    Toast.makeText(MainActivity.this, "Enter User Name",
      Toast.LENGTH_LONG).show();
    return;
   }

   String textAddress = editTextAddress.getText().toString();
   if (textAddress.equals("")) {
    Toast.makeText(MainActivity.this, "Enter Addresse",
      Toast.LENGTH_LONG).show();
    return;
   }
   
   msgLog = "";
   chatMsg.setText(msgLog);
   loginPanel.setVisibility(View.GONE);
   chatPanel.setVisibility(View.VISIBLE);

   chatClientThread = new ChatClientThread(
     textUserName, textAddress, SocketServerPORT);
   chatClientThread.start();
  }

 };

 private class ChatClientThread extends Thread {

  String name;
  String dstAddress;
  int dstPort;
  
  String msgToSend = "";
  boolean goOut = false;

  ChatClientThread(String name, String address, int port) {
   this.name = name;
   dstAddress = address;
   dstPort = port;
  }

  @Override
  public void run() {
   Socket socket = null;
   DataOutputStream dataOutputStream = null;
   DataInputStream dataInputStream = null;

   try {
    socket = new Socket(dstAddress, dstPort);
    dataOutputStream = new DataOutputStream(
      socket.getOutputStream());
    dataInputStream = new DataInputStream(socket.getInputStream());
    dataOutputStream.writeUTF(name);
    dataOutputStream.flush();

    while (!goOut) {
     if (dataInputStream.available() > 0) {
      msgLog += dataInputStream.readUTF();

      MainActivity.this.runOnUiThread(new Runnable() {

       @Override
       public void run() {
        chatMsg.setText(msgLog);
       }
      });
     }
     
     if(!msgToSend.equals("")){
      dataOutputStream.writeUTF(msgToSend);
      dataOutputStream.flush();
      msgToSend = "";
     }
    }

   } catch (UnknownHostException e) {
    e.printStackTrace();
    final String eString = e.toString();
    MainActivity.this.runOnUiThread(new Runnable() {

     @Override
     public void run() {
      Toast.makeText(MainActivity.this, eString, Toast.LENGTH_LONG).show();
     }
     
    });
   } catch (IOException e) {
    e.printStackTrace();
    final String eString = e.toString();
    MainActivity.this.runOnUiThread(new Runnable() {

     @Override
     public void run() {
      Toast.makeText(MainActivity.this, eString, Toast.LENGTH_LONG).show();
     }
     
    });
   } finally {
    if (socket != null) {
     try {
      socket.close();
     } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
    }

    if (dataOutputStream != null) {
     try {
      dataOutputStream.close();
     } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
    }

    if (dataInputStream != null) {
     try {
      dataInputStream.close();
     } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
    }

    MainActivity.this.runOnUiThread(new Runnable() {

     @Override
     public void run() {
      loginPanel.setVisibility(View.VISIBLE);
      chatPanel.setVisibility(View.GONE);
     }
     
    });
   }

  }
  
  private void sendMsg(String msg){
   msgToSend = msg;
  }
  
  private void disconnect(){
   goOut = true;
  }
 }

}

/res/layout/activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Char Client"
        android:textStyle="bold" />

    <LinearLayout
        android:id="@+id/loginpanel"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:visibility="visible" >

        <EditText
            android:id="@+id/username"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="User name" />

        <EditText
            android:id="@+id/address"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="dstAddress" />

        <TextView
            android:id="@+id/port"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/connect"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Connect..." />
    </LinearLayout>

 <LinearLayout
        android:id="@+id/chatpanel"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:visibility="gone" >
        
        <EditText
            android:id="@+id/say"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Say something" />
     
        <Button
            android:id="@+id/send"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Send" />
        
        <Button
            android:id="@+id/disconnect"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Disconnect" />

        <ScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <TextView
                android:id="@+id/chatmsg"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
        </ScrollView>
    </LinearLayout>

</LinearLayout>

Permission of "android.permission.INTERNET" is needed in AndroidManifest.xml.

Download the files.