android Socket实现简单聊天小程序

android Socket实现简单聊天小程序，供大家参考，具体内容如下

服务器端：

package org.hwq.echo; 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket; 

public class TalkServer {
  public static void main(String[] args) throws IOException{
    ServerSocket server = null;
    Socket client = null;
    BufferedReader in = null;
    PrintWriter out = null;
    try{
      server = new ServerSocket(4700);
      client = server.accept();
      out = new PrintWriter(client.getOutputStream());
      in = new BufferedReader(new InputStreamReader(client.getInputStream()));
      String line = in.readLine();
      while(!"bye".equals(line)){
        System.out.println("client:"+line);
        out.println("echo:"+line);
        out.flush();
        line = in.readLine();
      }
    }catch (Exception e) {
      e.printStackTrace();
      if(client !=null)
        client.close();
      if(server != null)
        server.close();
    }
  }
} 

手机端：

package org.hwq.cho; 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException; 

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast; 

public class EchoActivity extends Activity implements OnClickListener {
  EditText show,msg;
  Button send;
  Handler handler;
  Socket client;
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    handler = new MyHandler();
    show = (EditText) findViewById(R.id.show);
    msg = (EditText) findViewById(R.id.msg);
    send = (Button) findViewById(R.id.send);
    send.setOnClickListener(this);
  }
  @Override
  public void onClick(View arg0) {
    String message = msg.getText().toString();
//   System.out.println("msg:"+message);
    new EchoThread(EchoActivity.this,message).start();
  }
  public class MyHandler extends Handler{
    @Override
    public void handleMessage(Message msg) {
      switch(msg.what){
      case 1:
        Toast.makeText(EchoActivity.this, "建立连接失败", 0).show();
        break;
      case 2:
        String message = (String) msg.obj;
        System.out.println("Handler:"+message);
        show.append("\n"+message);
        break;
      }
    }
  }
  private class EchoThread extends Thread{
    private Context context;
    private String msg;
    EchoThread(Context context,String msg){
      this.context = context;
      this.msg = msg;
    }
    public void run(){
      if(client == null){
        try {
          client = new Socket("192.168.1.102",4700);
        } catch (IOException e) {
          Message message = new Message();
          message.what = 1;
          handler.sendMessage(message);
        }
      }
      System.out.println("建立连接");
      try{
        BufferedReader in;
        BufferedReader input;
        PrintWriter out;
        in = new BufferedReader(new InputStreamReader(client.getInputStream()));
        out = new PrintWriter(client.getOutputStream());
        String line = msg;
        if(!"bye".equals(line)){
          System.out.println("line:"+line);
          out.println(line);
          out.flush();
          String echo = in.readLine();
          System.out.println("server:"+echo);
          Message message = new Message();
          message.obj = echo;
          message.what = 2;
          handler.sendMessage(message);
        }
      }catch (Exception e) { 

      }
    }
  }
} 

注意几点：

1、添加网络权限

<uses-permission android:name="android.permission.INTERNET"/>

如果没添加，无法使用socket连接网络。
2、在新启线程中不要使用android系统UI界面
在EchoThrad的run()方法里面，有下面代码：

if(client == null){
        try {
          client = new Socket("192.168.1.102",4700);
        } catch (IOException e) {
          Message message = new Message();
          message.what = 1;
          handler.sendMessage(message);
        }
      }

这里的handler.sendMessage(message);是发送一个消息给handler,然后handler根据消息弹出一个Toast显示连接失败。如果这里直接使用

Toast.makeText(EchoActivity.this, "建立连接失败", 0).show();

会报如下错：

Can't create handler inside thread that has not called Looper.prepare()

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。