android客户端在多个界面切换时保持socket的链接

android客户端在多个界面切换时保持socket的链接研究一个socket在多个界面切换时保持链接的问题，现在我提供客户端的源码给有需要的人参考。

1、ApplicationUtil类：import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.IOException;import .Socket;import .UnknownHostException;import android.app.Application;public class ApplicationUtil extends Application{private Socket socket;private DataOutputStream out = null;private DataInputStream in = null;public void init() throws IOException, Exception{this.socket = new Socket("192.168.1.104",10202);this.out = new DataOutputStream(socket.getOutputStream());this.in = new DataInputStream(socket.getInputStream());}public Socket getSocket() {return socket;}public void setSocket(Socket socket) {this.socket = socket;}public DataOutputStream getOut() {return out;}public void setOut(DataOutputStream out) {this.out = out;}public DataInputStream getIn() {return in;}public void setIn(DataInputStream in) {this.in = in;}}2、AndroidMainifest.xml中application的配置：<manifest xmlns:android="/apk/res/android"package="com.login"android:versionCode="1"android:versionName="1.0" ><uses-sdkandroid:minSdkVersion="10"android:targetSdkVersion="15" /><applicationandroid:name="com.util.ApplicationUtil"android:icon="@drawable/ic_launcher"android:label="@string/app_name"android:theme="@style/AppTheme" ><activityandroid:name=".LoginActivity"android:label="@string/title_activity_main" ><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="UNCHER" /> </intent-filter></activity><activity android:name=".MainActivity"/></application><!-- 振动需要的权限--><uses-permission android:name="android.permission.VIBRA TE"/><!-- 声明网络权限--><uses-permission android:name="android.permission.INTERNET"/></manifest>3、LoginActivity类：import java.io.BufferedWriter;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.io.PrintWriter;import .Socket;import .UnknownHostException;import com.login.R;import com.util.ApplicationUtil;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class LoginActivity extends Activity{private EditText usernameT;private EditText passwordT;private Button loginButton;private Socket socket;private DataOutputStream out;private DataInputStream in;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(yout.login);usernameT = (EditText) findViewById(ername);passwordT = (EditText) findViewById(R.id.password);loginButton = (Button) findViewById(R.id.login);loginButton.setOnClickListener(new OnClickListener(){public void onClick(View v) {ApplicationUtil appUtil = (ApplicationUtil) LoginActivity.this.getApplication();try {appUtil.init();Socket socket = appUtil.getSocket();out = appUtil.getOut();in = appUtil.getIn();} catch (IOException e1) {e1.printStackTrace();} catch (Exception e1) {e1.printStackTrace();}String username = usernameT.getText().toString();String password = passwordT.getText().toString();MD5 md5 = new MD5();String ss = md5.MD5(username+"|"+password);try {//发送数据String str = "[login]|"+ss;out.writeBytes(str);out.flush();System.out.println("str ===> "+str);//创建一个缓冲字节数int r = in.available();while(r==0){r = in.available();}byte[] b = new byte[r];in.read(b);String result = new String(b,"utf-8");System.out.println("result = "+result);if(result.equals("登陆成功0")){Intent intent = new Intent();intent.setClass(LoginActivity.this, MainActivity.class);startActivity(intent);}else{Intent intent = new Intent();intent.setClass(LoginActivity.this, MainActivity.class);startActivity(intent);}} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}});}}4、MainActivity类：import java.io.BufferedReader;import java.io.DataInputStream;import java.io.IOException;import java.io.InputStreamReader;import .Socket;import com.image.TestActivity;import com.login.R;import com.util.ApplicationUtil;import android.media.RingtoneManager;import .Uri;import android.os.Bundle;import android.os.Handler;import android.os.Looper;import android.os.Message;import android.provider.MediaStore.Audio;import android.app.Activity;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.content.Context;import android.content.Intent;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {private EditText mess;private Socket socket;private Handler handler;private DataInputStream in;private NotificationManager nm;private Notification n;private int messageNotificationID = 0;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(yout.success);mess = (EditText) findViewById(R.id.message);ApplicationUtil appUtil = (ApplicationUtil) MainActivity.this.getApplication();socket = appUtil.getSocket();in = appUtil.getIn();handler = new Handler(){@Overridepublic void handleMessage(Message msg) {//如果来自子线程if(msg.what == 0x123){mess.append(msg.obj.toString()+"\n");//消息通知mynoti();}}};//调用线程myThread();}//JA V A可以设置读写缓冲区的大小-setReceiveBufferSize(int size), setSendBufferSize(int size)。