Android之socket多线程

一、添加权限

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

二、输入输出流

客户端和服务器端的输入输出流的问题容易搞混淆：如下图

在客户端：

socket.getInputStream();从socket读来自服务器的数据

socket.getOutputStream();向socket中写数据，传给服务器，服务器在它的socket的输入流读这个数据

在服务器端：

socket.getInputStream();从socket读来自客户端的数据

socket.getOutputStream();向socket中写数据，传给客户端，客户端在它的socket的输入流读这个数据

就是说客户端和服务器端的输入输出流是对应的，输入流连接到输出流　

输入输出流的包装：

方法一：数据二进制流

DataInputStream in=new DataInputStream(socket.getInputStream());//接收客户端信息
DataOutputStream out=new DataOutputStream(socket.getOutputStream());  //向客户端发送消息

方法二：

PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

三、客户端/服务器端实现

创建服务器端的步骤：
1，指定端口实例化一个ServerSocket

2,调用ServerSocket的accept方法等待连接期间阻塞

3，获取位于底层的Socket流进行读写操作

4，将数据封装成流

5，对Socket进行读写

6，关闭流

创建客户端的步骤：

1，通过IP地址和端口实例化Socket，请求连接服务器

2，获取位于底层的Socket流进行读写操作

3，将数据封装成流（BufferedReader/PrintWriter,DataOutputStream/DataInputStream）的实例

4，对Socket进行读写

5，关闭流

socketClient,java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
 
public class socketClient extends Activity {
    private Button button;
    private TextView text;
    private EditText edit;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        button = (Button) findViewById(R.id.button);
        edit = (EditText) findViewById(R.id.edit);
        text = (TextView) findViewById(R.id.text);
 
        button.setOnClickListener(new View.OnClickListener() {
            private Socket socket = null;
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
 
                String sendMsg = edit.getText().toString() + "
";
 
                try {
                    socket = new Socket("192.168.0.37", 8888); // 创建Socket，其中ip地址为我的PC机器的地址，手机通过wifi上网和服务器在一个网段
 
                    // PrintWriter out = new PrintWriter(new BufferedWriter(new
                    // OutputStreamWriter(socket.getOutputStream())),true);
                    // out.println(sendMsg);
                    //                  
                    // BufferedReader in = new BufferedReader(new
                    // InputStreamReader(socket.getInputStream()));
                    // String readMsg = in.readLine();
                    // if(readMsg !=null){
                    // text.setText(readMsg);
                    // }else{
                    // text.setText("错误");
                    // }
                    //                  
                    // out.close();
                    // in.close();
                    // socket.close();
 
                    DataOutputStream out = new DataOutputStream(socket
                            .getOutputStream()); // 向服务器发送消息
                    out.writeUTF(sendMsg);
                    out.flush();
 
                    DataInputStream in = new DataInputStream(socket
                            .getInputStream()); // 接收来自服务器的消息
                    String readMsg = in.readUTF();
                    if (readMsg != null) {
                        text.setText(readMsg);
                    }
                    out.close();
                    in.close();
                    socket.close();
 
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

Server.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
 
public class Server {
    public Server(){
        new ServerThread().start();
    }
    class ServerThread extends Thread{
        public void run() {
            try {
                ServerSocket ss=new ServerSocket(8888); ////创建一个ServerSocket对象，并让这个ServerSocket在8888端口监听
                while(true){
                    Socket socket=ss.accept(); //调用ServerSocket的accept()方法，接受客户端所发送的请求，如果客户端没有发送数据，那么该线程就停滞不继续
//                  try {
//                      BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));  //接收客户端信息
//                      String readline = in.readLine();
//                      System.out.println("readline:"+readline);
//                      
//                      PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
//                      out.println("link server success");
//                      
//                      in.close();   //关闭流
//                      out.close();//关闭流
//                      socket.close();//关闭打开的socket
//                      
//                  } catch (Exception e) {
//                      // TODO: handle exception
//                  }finally{
//                  //  socket.close();//
//                  }
                    try {
                        DataInputStream in=new DataInputStream(socket.getInputStream());//接收客户端信息
                        String readline=in.readUTF();
                        System.out.println(readline);
                             
                        DataOutputStream out=new DataOutputStream(socket.getOutputStream());  //向客户端发送消息
                        out.writeUTF("link server success");
                        out.flush();
                         
                        in.close();   //关闭流
                        out.close();//关闭流
                        socket.close();//关闭打开的socket
                         
                    } catch (Exception e) {
                        System.out.println(e.getMessage());
                    }
                }
            } catch (IOException e) {
                System.out.println(e.getMessage());
            }
        }
    }
    public static void main(String[] args) throws IOException {
        new Server();   //开启服务器
    }
     
 
}