Socket 编程基础知识:
主要分服务器端编程和客户端编程。
服务器端编程步骤:
1: 创建服务器端套接字并绑定到一个端口上(0-1023是系统预留的,最好大约1024)
2: 套接字设置监听模式等待连接请求
3: 接受连接请求后进行通信
4: 返回,等待赢一个连接请求
客户端编程步骤:
1: 创建客户端套接字(指定服务器端IP地址与端口号)
2: 连接(Android 创建Socket时会自动连接)
3: 与服务器端进行通信
4: 关闭套接字
Android Socket 通信原理注意:
1: 中间的管道连接是通过InputStream/OutputStream流实现的。
2: 一旦管道建立起来可进行通信
3: 关闭管道的同时意味着关闭Socket
4: 当对同一个Socket创建重复管道时会异常
5: 通信过程中顺序很重要:服务器端首先得到输入流,然后将输入流信息输出到其各个客户端
客户端先建立连接后先写入输出流,然后再获得输入流。不然活有EOFException的异常。
不要忘记添加Internet权限,不要忘记添加Internet权限,不要忘记添加Internet权限
服务器端代码的编写:
import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.net.ServerSocket; import java.net.Socket; import java.util.ArrayList; public class Server { static ServerSocket aServerSocket = null; // Server Socet. DataInputStream aDataInput = null; // Server input Stream that to // receive msg from client. DataOutputStream aDataOutput = null; // Server output Stream that to static ArrayList list = new ArrayList(); public static void main(String[] args) { try { aServerSocket = new ServerSocket(50003); // listen 8888 port. System.out.println("already listen 50003 port."); } catch (Exception e) { e.printStackTrace(); } int num = 0; while (num < 10) { Socket aSessionSoket = null; try { aSessionSoket = aServerSocket.accept(); MyThread thread = new Server().new MyThread(aSessionSoket); thread.start(); num = list.size(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } } } class MyThread extends Thread { Socket aSessionSoket = null; public MyThread(Socket socket) { aSessionSoket = socket; } public void run() { try { aDataInput = new DataInputStream(aSessionSoket.getInputStream()); aDataOutput = new DataOutputStream(aSessionSoket.getOutputStream()); list.add(aDataOutput); while (true) { String msg = aDataInput.readUTF(); // read msg. if (!msg.equals("connect...")) { System.out.println("ip: "+ aSessionSoket.getInetAddress());// ip.System.out.println("receive msg: " + msg); for (int i = 0; i < list.size(); i++) { DataOutputStream output = (DataOutputStream) list.get(i); output.writeUTF(msg + "----" + list.size()); } if (msg.equals("end")) break; } aDataOutput.writeUTF(""); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try { aDataInput.close(); if (aDataOutput != null) aDataOutput.close(); list.remove(aDataOutput); aSessionSoket.close(); } catch (Exception e2) {
注意问题:为了实现对于多个客户端的处理,使用了多线程的操作,每个线程维护一个Socket的连接与通信,新连接的Socket的管道被加入到 ArrayList中。对于输出流的操作是对于所有的连接的客户端进行写数据。对于关闭了Socket的客户端管道从List中移除。
客户端代码的编写:
import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.net.InetSocketAddress; import java.net.Socket; import java.net.SocketAddress; 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 SocketActivity extends Activity { EditText editText = null; Button sendButton = null; TextView display = null; Socket client = null; MyHandler myHandler; DataOutputStream dout; DataInputStream din; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.clientsocket); editText = (EditText) findViewById(R.id.message); sendButton = (Button) findViewById(R.id.send); display = (TextView) findViewById(R.id.display); sendButton.setOnClickListener(listener); try { client = new Socket("192.168.0.120", 50003); dout = new DataOutputStream(client.getOutputStream()); din = new DataInputStream(client.getInputStream()); } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } myHandler = new MyHandler(); MyThread m = new MyThread(); m.start(); } class MyHandler extends Handler { public MyHandler() { } // 子类必须重写此方法,接受数据 @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub Log.d("MyHandler", "handleMessage......"); super.handleMessage(msg); // 此处可以更新UI if (client != null && client.isConnected()) { Log.i("handler..", "*-----*"); try { dout.writeUTF("connect..."); String message = din.readUTF(); if (!message.equals("")) display.setText(display.getText().toString() + " "+ "服务器发来的消息--:" + message); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } class MyThread extends Thread { public void run() { while (true) { try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } Message msg = new Message(); SocketActivity.this.myHandler.sendMessage(msg); } } } OnClickListener listener = new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String sendText = editText.getText().toString(); try { // din = new DataInputStream(client.getInputStream()); dout.writeUTF(sendText); /* * display.setText(display.getText().toString() + " " + * "服务器发来的消息:" + din.readUTF()); */ /* * display.setText(display.getText().toString() + " " + * "服务器发来的消息--:" + din.readUTF()); */ } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }; }