Android学习笔记--通过wifi向服务器端发送数据

（转自http://www.cnblogs.com/zhxiang/archive/2011/07/21/2112825.html）

客户端程序：

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package com.zx.android;

import android.app.Activity;

import android.os.Bundle;

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;

import android.content.Context;

import android.widget.Toast;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

import android.net.wifi.WifiManager;

import java.net.Socket;

import com.zx.android.ClientActivity;

public class ClientActivity extends Activity {

/** Called when the activity is first created. */

private Button startButton = null;

private Button stopButton = null;

private Button checkButton = null;

private WifiManager wifiManager = null;

private final String DEBUG_TAG= "Activity01";

private TextView mTextView=null;

private EditText mEditText=null;

private Button mButton=null;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

mButton = (Button)findViewById(R.id.Button01);

mTextView=(TextView)findViewById(R.id.TextView01);

mEditText=(EditText)findViewById(R.id.EditText01);

startButton = (Button)findViewById(R.id.startWifi);

stopButton = (Button)findViewById(R.id.stopWifi);

checkButton = (Button)findViewById(R.id.checkWifi);

startButton.setOnClickListener(new StartWifiListener());

stopButton.setOnClickListener(new StopWifiListener());

checkButton.setOnClickListener(new CheckWifiListener());

//登陆

mButton.setOnClickListener(new OnClickListener()

{

public void onClick(View v)

{

Socket socket = null;

String message = mEditText.getText().toString() + "/r/n";

try

{

//创建Socket

socket = new Socket("192.168.1.102",54321);

//向服务器端发送消息

PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())),true);

out.println(message);

//接收来自服务器端的消息

BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

String msg = br.readLine();

if ( msg != null )

{

mTextView.setText(msg);

}

else

{

mTextView.setText("数据错误!");

}

//关闭流

out.close();

br.close();

//关闭Socket

socket.close();

}

catch (Exception e)

{

// TODO: handle exception

Log.e(DEBUG_TAG, e.toString());

}

});

}

class StartWifiListener implements OnClickListener{

public void onClick(View v) {

wifiManager = (WifiManager)ClientActivity.this.getSystemService(Context.WIFI_SERVICE);

wifiManager.setWifiEnabled(true);

System.out.println("wifi state --->" + wifiManager.getWifiState());

Toast.makeText(ClientActivity.this, "当前Wifi网卡状态为" +

wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();

}

class StopWifiListener implements OnClickListener{

public void onClick(View arg0) {

wifiManager = (WifiManager)ClientActivity.this.getSystemService(Context.WIFI_SERVICE);

wifiManager.setWifiEnabled(false);

System.out.println("wifi state --->" + wifiManager.getWifiState());

Toast.makeText(ClientActivity.this, "当前Wifi网卡状态为" +

wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();

}

class CheckWifiListener implements OnClickListener{

public void onClick(View v) {

wifiManager = (WifiManager)ClientActivity.this.getSystemService(Context.WIFI_SERVICE);

System.out.println("wifi state --->" + wifiManager.getWifiState());

Toast.makeText(ClientActivity.this, "当前Wifi网卡状态为" +

wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();

}

这个是我在手机上运行时截的图，下面三个按钮是操作wifi网关的按钮，下面的那个提示框是按下这个按钮出现的，数字为0表示正在关闭wifi，数字2表示正在开启wifi，数字1表示wifi处于关闭状态，数字3表示 wifi处于开启状态。

上面的的发送按钮可以发送数据到服务器，实验室的是局域网，没有无线网络，我利用一个无线路由与电脑相连，在利用手机wifi搜索到该网络，手机与电脑构成局域网，便可发送数据。至于服务器端，可以采用网络调试助手接收数据，协议选择TCP服务器，ip地址和端口视自己情况定。

当然也可以自己写个服务器端程序，再在命令行窗口中显示接收到的数据。

服务器端程序：

package com.zx.android;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

import java.net.ServerSocket;

import java.net.Socket;

public class Server implements Runnable

{

public void run()

{

try

{

//创建ServerSocket

ServerSocket serverSocket = new ServerSocket(54321);

while (true)

{

//接受客户端请求

Socket client = serverSocket.accept();

System.out.println("accept");

try

{

//接收客户端消息

BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));

String str = in.readLine();

System.out.println("read:" + str);

//向服务器发送消息

PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(client.getOutputStream())),true);

out.println("server message");

//关闭流

out.close();

in.close();

}

catch (Exception e)

{

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

e.printStackTrace();

}

finally

{

//关闭

client.close();

System.out.println("close");

}

catch (Exception e)

{

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

}

//main函数，开启服务器

public static void main(String[] args)

{

Thread desktopServerThread = new Thread(new Server());

desktopServerThread.start();

}