Android网络编程之Socket通信

Love The Way You Lie 2022-08-08 00:54 245阅读 0赞

#  Socket（套接字）是一种通信机制，可以实现单机或跨网络进行通信，其创建需要明确的区分C（客户端）/S（服务器端），支持多个客户端连接到同一个服务器。有两种传输模式：  1）、面向连接的传输：基于TCP协议，可靠性高，但效率低；  2）、面向无连接的传输：基于UDP协议，可靠性低，但效率高；   Android中，直接采用Socket通信应该是我们遇到的最低级的网络运用。尽管已经作了很大程度的抽象，但是纯粹的Socket通信，仍然给开发者留下很多细节需要处理，尤其在服务器端，开发者需要处理多线程以及数据缓冲等的设计问题。相对而言，处于更高抽象层的HTTP等，已经对Socket通信中需要处理的技术细节进行了很好的封装，开发者无须关心，因此，HTTP在网络开发中通常具有决定性的优势。      Android在其核心库的java包中，提供了用于客户端的Socket class和用于服务器端的ServerSocket class，分别位于$SOURCE/libcore/luni/src/main/java/java/net/Socket.java和$SOURCE/libcore/luni/src/main/java/java/net/ServerSocket.java文件中。分析两个class的源码，可以看出封装考虑的很全面，只构造方法一向每个class都考虑了很多种使用情况。由于本人只是初学者，很多理解的不深入，这里只抛砖引玉的对两个class的构造方法分别介绍一种，就是我下面的程序中用到的：  Socket(String dstName, int dstPort)：创建一个以流的方式（基于TCP协议）连接到目标机（这里可以理解为服务器）的客户端Socket；dstName是目标机的IP地址，dstPort是要连接的目标机的端 口号。这里要注意对端口的理解，它不能理解为物理上的一个接口，而是对计算机中一块特殊内存区域的形象表述。  ServerSocket(int aport)：创建一个绑定到本机指定端口的服务端Socket；aport就是指定的本机端口。与上述客户端Socket对应，通过TCP连接时，ServerSocket创建后需要在aport端口上进行监听，等待客户端的连接。       启动 service 和 activity        mContext.startService(new Intent(mContext, SocketService.class));      Intent intent = new Intent();   intent.setClass(mContext, SocketClientDemo.class);   mContext.startActivity(intent);       service ：服务端  package com.android.settings;      import java.io.BufferedReader;   import java.io.BufferedWriter;   import java.io.IOException;   import java.io.InputStreamReader;   import java.io.OutputStreamWriter;   import java.io.PrintWriter;   import java.net.ServerSocket;   import java.net.Socket;      import android.app.Service;   import android.content.Intent;   import android.os.IBinder;      public class SocketService extends Service \{   Thread mServiceThread;      Socket client;      @Override   public IBinder onBind(Intent intent) \{   // TODO Auto-generated method stub   return null;   \}      @Override   public void onCreate() \{   // TODO Auto-generated method stub   super.onCreate();      mServiceThread = new Thread(new SocketServerThread());   \}      @Override   public void onStart(Intent intent, int startId) \{   // TODO Auto-generated method stub   super.onStart(intent, startId);      mServiceThread.start();   \}      @Override   public void onDestroy() \{   // TODO Auto-generated method stub   super.onDestroy();   \}      public class SocketServerThread extends Thread \{   private static final int PORT = 54321;      private SocketServerThread() \{   \}      @Override   public void run() \{   try \{   ServerSocket server = new ServerSocket(PORT);      while (true) \{   System.out.println("tian begin client connected");   client = server.accept();   System.out.println(" tian client connected");      BufferedReader reader = new BufferedReader(   new InputStreamReader(client.getInputStream()));   System.out.println(" tian read from client:");      String textLine = reader.readLine();   if (textLine.equalsIgnoreCase("EXIT")) \{   System.out   .println(" tian EXIT invoked, closing client");   break;   \}      System.out.println(textLine);      PrintWriter writer = new PrintWriter(new BufferedWriter(   new OutputStreamWriter(client.getOutputStream())));      System.out.println(" return tian read from client:"   \+ textLine);   writer.println(" tian ECHO from server: " + textLine);   writer.flush();      writer.close();   reader.close();   \}   \} catch (IOException e) \{   // TODO Auto-generated catch block   System.err.println(e);   \}   \}      \}   \}       package com.android.settings;      import java.io.BufferedReader;   import java.io.BufferedWriter;   import java.io.IOException;   import java.io.InputStreamReader;   import java.io.OutputStreamWriter;   import java.io.PrintWriter;   import java.net.Socket;   import java.net.UnknownHostException;      import android.app.Activity;   import android.os.Bundle;   import android.os.Handler;   import android.os.Message;   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 SocketClientDemo extends Activity \{   private static final String SERVERIP = "127.0.0.1";   private static final int SERVERPORT = 54321;      private static final String TAG = "SocketClientDemo";      TextView mMsgRev;   EditText mMsgEdit;   Button mMsgSendBtn;      String mSendMsg;   String mReceivedMsg;      class MyThread implements Runnable \{   private String name;      public MyThread(String name) \{   this.name = name;   \}      public void run() \{   // for (int i = 0; i < 100; i++) \{   // System.out.println("线程开始：" + this.name + ",i=" + i);      Log.d(TAG, "MyThread execu");   // \}   \}   \};      class MyThread2 extends Thread \{      @Override   public void run() \{   // TODO Auto-generated method stub   Log.d(TAG, "MyThread2 execu");   \}   \};      class MyThread3 extends Thread \{      private String name;      public MyThread3(String name) \{   // super();   this.name = name;   \}      @Override   public void run() \{   // TODO Auto-generated method stub   Log.d(TAG, "MyThread3 execu" + "name=" + name);      Socket socket = null;   mSendMsg = mMsgEdit.getText().toString();      try \{   socket = new Socket(SERVERIP, SERVERPORT);      PrintWriter writer = new PrintWriter(new BufferedWriter(   new OutputStreamWriter(socket.getOutputStream())));   writer.println(mSendMsg);   writer.flush();      BufferedReader reader = new BufferedReader(   new InputStreamReader(socket.getInputStream()));   mReceivedMsg = reader.readLine();      Message meaage = mHander.obtainMessage();   meaage.arg1 = 1;   mHander.sendMessage(meaage);      writer.close();   reader.close();   socket.close();   \} catch (UnknownHostException e) \{   // TODO Auto-generated catch block   e.printStackTrace();   \} catch (IOException e) \{   // TODO Auto-generated catch block   e.printStackTrace();   \}   \}   \}      /\*\* Called when the activity is first created. \*/   @Override   public void onCreate(Bundle savedInstanceState) \{   super.onCreate(savedInstanceState);   setContentView(R.xml.beidou\_detail\_preference\_settings);      mMsgRev = (TextView) findViewById(R.id.receive\_msg);   mMsgEdit = (EditText) findViewById(R.id.edit\_msg);   mMsgSendBtn = (Button) findViewById(R.id.send\_msg);      mMsgSendBtn.setOnClickListener(new OnClickListener() \{   @Override   public void onClick(View v) \{      /\*   \* MyThread thread = new MyThread("00"); new   \* Thread(thread).start();   \*   \* new MyThread2().start();   \*/      MyThread3 thread3 = new MyThread3("33");   thread3.start();      \}   \});   \}      final Handler mHander = new Handler() \{      @Override   public void handleMessage(Message msg) \{   // TODO Auto-generated method stub      if (mReceivedMsg != null) \{   mMsgRev.setText(mReceivedMsg);   \} else \{   mMsgRev.setText("tian receive data error");   \}   super.handleMessage(msg);   \}      \};   \}       activity : 客户端       package com.android.settings;      import java.io.BufferedReader;   import java.io.BufferedWriter;   import java.io.IOException;   import java.io.InputStreamReader;   import java.io.OutputStreamWriter;   import java.io.PrintWriter;   import java.net.Socket;   import java.net.UnknownHostException;      import android.app.Activity;   import android.os.Bundle;   import android.os.Handler;   import android.os.Message;   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 SocketClientDemo extends Activity \{   private static final String SERVERIP = "127.0.0.1";   private static final int SERVERPORT = 54321;      private static final String TAG = "SocketClientDemo";      TextView mMsgRev;   EditText mMsgEdit;   Button mMsgSendBtn;      String mSendMsg;   String mReceivedMsg;      class MyThread implements Runnable \{   private String name;      public MyThread(String name) \{   this.name = name;   \}      public void run() \{   // for (int i = 0; i < 100; i++) \{   // System.out.println("线程开始：" + this.name + ",i=" + i);      Log.d(TAG, "MyThread execu");   // \}   \}   \};      class MyThread2 extends Thread \{      @Override   public void run() \{   // TODO Auto-generated method stub   Log.d(TAG, "MyThread2 execu");   \}   \};      class MyThread3 extends Thread \{      private String name;      public MyThread3(String name) \{   // super();   this.name = name;   \}      @Override   public void run() \{   // TODO Auto-generated method stub   Log.d(TAG, "MyThread3 execu" + "name=" + name);      Socket socket = null;   mSendMsg = mMsgEdit.getText().toString();      try \{   socket = new Socket(SERVERIP, SERVERPORT);      PrintWriter writer = new PrintWriter(new BufferedWriter(   new OutputStreamWriter(socket.getOutputStream())));   writer.println(mSendMsg);   writer.flush();      BufferedReader reader = new BufferedReader(   new InputStreamReader(socket.getInputStream()));   mReceivedMsg = reader.readLine();      Message meaage = mHander.obtainMessage();   meaage.arg1 = 1;   mHander.sendMessage(meaage);      writer.close();   reader.close();   socket.close();   \} catch (UnknownHostException e) \{   // TODO Auto-generated catch block   e.printStackTrace();   \} catch (IOException e) \{   // TODO Auto-generated catch block   e.printStackTrace();   \}   \}   \}      /\*\* Called when the activity is first created. \*/   @Override   public void onCreate(Bundle savedInstanceState) \{   super.onCreate(savedInstanceState);   setContentView(R.xml.beidou\_detail\_preference\_settings);      mMsgRev = (TextView) findViewById(R.id.receive\_msg);   mMsgEdit = (EditText) findViewById(R.id.edit\_msg);   mMsgSendBtn = (Button) findViewById(R.id.send\_msg);      mMsgSendBtn.setOnClickListener(new OnClickListener() \{   @Override   public void onClick(View v) \{      /\*   \* MyThread thread = new MyThread("00"); new   \* Thread(thread).start();   \*   \* new MyThread2().start();   \*/      MyThread3 thread3 = new MyThread3("33");   thread3.start();      \}   \});   \}      final Handler mHander = new Handler() \{      @Override   public void handleMessage(Message msg) \{   // TODO Auto-generated method stub      if (mReceivedMsg != null) \{   mMsgRev.setText(mReceivedMsg);   \} else \{   mMsgRev.setText("tian receive data error");   \}   super.handleMessage(msg);   \}      \};   \}           #