案例实现的是简单的Socket通信，当client（Androidclient）连接到指定server以后，server向client发送一句话文字信息（你能够拓展其他的了）

先看一下服务端程序的实现吧

Server.java

import java.io.IOException;

import java.io.OutputStream;

import java.net.ServerSocket;

import java.net.Socket;

public class Server {

/**

* @param args

* @throws IOException

*/

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

// TODO Auto-generated method stub

// 创建一个ServerSocket,用于监听clientsocket的连接请求

ServerSocket ss = new ServerSocket(30000);

// 採用循环不断接受来自client的请求,server端也相应产生一个Socket

while (true) {

Socket s = ss.accept();

OutputStream os = s.getOutputStream();

os.write("你好，由于你上线了，所以server发给了你这条信息".getBytes("utf-8"));

os.close();

s.close();

}

}

}

接下来实现的就是手机client的上线并接收数据了，看一下 MainActivity.java

package com.example.socket;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.Socket;

import java.net.UnknownHostException;

import android.app.Activity;

import android.os.Bundle;

import android.os.Handler;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class MainActivity extends Activity {

private TextView display;

private Handler handler;

private String host;

private Button btn;

private Socket socket;

private String line;

private EditText et;

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

handler = new Handler();

btn = (Button) findViewById(R.id.send);

et = (EditText)findViewById(R.id.editText1);

et.setText("192.168.1.100");

OnClickListener listener = new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

new Thread() {

public void run() {

try {

host = et.getText().toString();

socket = new Socket(host, 30000);

// 设置10秒之后即觉得是超时

socket.setSoTimeout(10000);

BufferedReader br = new BufferedReader(

new InputStreamReader(

socket.getInputStream()));

line = br.readLine();

Log.d("Read:", line);

br.close();

socket.close();

} catch (UnknownHostException e) {

// TODO Auto-generated catch block

Log.e("UnknownHost", "没找到主机");

e.printStackTrace();

} catch (IOException e) {

Log.e("IOException", "输入输出出现错误");

// TODO Auto-generated catch block

e.printStackTrace();

}

handler.post(new Runnable(){

@Override

public void run() {

// TODO Auto-generated method stub

display = (TextView) findViewById(R.id.display);

display.setText(line);

}});

}

}.start();

}

};

btn.setOnClickListener(listener);

}

}

这里需要注意的是，与网络相关的更新UI界面的一定不以在主线程中进行更，必需要用到Handler实现UI更新

好了。看一下布局文件

<RelativeLayout 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"

tools:context=".MainActivity" >

<TextView

android:id="@+id/display"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_centerVertical="true"

android:text="@string/hello_world" />

<Button

android:id="@+id/send"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true"

android:layout_marginTop="72dp"

android:text="Link to Server" />

<EditText

android:id="@+id/editText1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true"

android:layout_marginTop="18dp"

android:ems="10" >

<requestFocus />

</EditText>

</RelativeLayout>

 

最后。不得不提的是，由于用到了网络，所以在AndroidMainFest.xml中千万不要忘记加上下面权限

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