Socket编程——客户端，服务器端的读写操作

URL网络编程，最大的特征就是一对一的响应！

1：客户端“写”，服务器端用于“读”

package coreBookSocket2;

import java.io.InputStreamReader;
import java.io.Reader;
import java.net.ServerSocket;
import java.net.Socket;

/*
 * 这边为服务器端的读取
 */

/*
 * 1：首先建立一个ServerSocket监听在端口8888上面，服务器端只需要定义和客户端相同的端口号即可
 * 2：服务器端尝试接受来自客户端的请求
 * 3：和客户端连接好了之后，就可以读取来自客户端的输入信息
 * 4：定义一个StringBuilder对象用来保存来自客户端的信息
 * 5：关闭Reader，client,server等占用资源的对象
 */
public class clientWtiteserverOpen {
    
    public static void main(String[] args) throws Exception{
        ServerSocket server=new ServerSocket(8888);
        Socket client =server.accept();
        Reader reader=new InputStreamReader(client.getInputStream());        //客户端获取自己的输入流
        char[] ch=new char[64];
        int len;
        StringBuilder sb=new StringBuilder();
        while( ( len=reader.read(ch) )!=-1)
        {
            sb.append(ch, 0, len);
        }
        System.out.println("From Client:"+sb);
        reader.close();
        client.close();
        server.close();
    }
}

package coreBookSocket2;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.Socket;
import java.net.UnknownHostException;
/*
 * 这边为客户端的写出
 */

/*
 * 1：首先建立一个客户端的监听端口和IP地址，用相同的端口号与服务器端建立连接
 * 2：从客户端向服务器端写出数据
 */
public class clientWriteserverOpen2 {
    public static void main(String[] args) throws UnknownHostException, IOException {
        
        Socket client=new Socket("127.0.0.1", 8888);
        Writer writer=new OutputStreamWriter(client.getOutputStream());
        writer.write("Hello server");
        writer.flush();
        writer.close();
        client.close();
        
    }

}

 2：客户端先写后读，服务器端先读后写

服务器端：

package ClientAndServerWriteBoth;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.net.ServerSocket;
import java.net.Socket;

/*
 * 服务器端的编写
 *  服务器端是先读后写，那么客户端必定是先写后读
 */

public class server {
    public static void main(String[] args) throws IOException {
        
        ServerSocket server=new ServerSocket(6666);
        Socket client=server.accept();
        
        Reader reader=new InputStreamReader(client.getInputStream());
        char[] ch=new char[20];
        int len;
        StringBuilder sb=new StringBuilder();
        String temp;
        int index;
        
        while(( len=reader.read(ch)) !=-1)
        {
            temp=new String(ch, 0, len);
            if( (index = temp.indexOf("eof")) != -1)//遇到eof时就结束接收,    这个地方没有怎么看明白？为什么到eof就结束？
            {
                sb.append(temp.substring(0, index));
                break;
            }
            sb.append(temp);
        }
        System.out.println("---From Client:  "+sb);
        
        Writer writer=new OutputStreamWriter(client.getOutputStream());
        writer.write("Hello Client I'm server! ");
        writer.flush();
        writer.close();
        reader.close();
        client.close();
        server.close();
    }
}

客户端：

package ClientAndServerWriteBoth;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.net.Socket;
import java.net.UnknownHostException;

/*
 * 客户端的编写，客户端先写后读
 * 1:客户端设定特定的端口号与服务器端连接
 */

public class client {
    public static void main(String[] args) throws UnknownHostException, IOException {
        
        Socket client=new Socket("127.0.0.1", 6666);
        Writer writer=new OutputStreamWriter(client.getOutputStream());
        writer.write("Hello server， I'm your father,client!  哈哈哈哈哈");
        writer.flush();
        //写完了开始读
        
        Reader reader=new InputStreamReader(client.getInputStream());
        char[] ch=new char[20];
        int len;
        StringBuffer sb=new StringBuffer();
        String temp;
        int index;
        
        while( (len=reader.read(ch))!=-1)
        {
            temp=new String(ch, 0, len);
                    if(( index=temp.indexOf("eof"))!=-1)
                    {
                        sb.append(temp.substring(0, index));
                        break;
                    }
            sb.append(new String(ch, 0, len));
        }
        System.out.println("---From Server:  "+sb);
        writer.close();
        reader.close();
        client.close();    
    }
}

 3：一个服务器端，对应多个客户端的连接

     一个服务器端和多个客户端连接最好的方式就是用线程，因为服务器端接受客户端的连接的accept（）方法是阻塞式的。

服务器端：

package oneServerForLotsClient;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.net.ServerSocket;
import java.net.Socket;
/*
 * 这边主要是服务器的demo的编写
 * 1：仍然是准备工作，让服务器端和客户端之间建立相同的端口号，实现连接。
 * 2:----因为客户端那边是多个对象连接服务器端，因此需要一个死循环让服务器一直接受连接客户端的连接请求！！！
 *                 建立一个新的线程去处理客户端的请求
 *3:服务器端首先是“读取” 客户端发送过来的信息
 */

public class Server 
{
    public static void main(String[] args) throws IOException 
    {
        
        ServerSocket server=new ServerSocket(6868);
        while(true)
            {
            Socket client=server.accept();
            new Thread(new Task(client) ).start();
            }
    }
}

package oneServerForLotsClient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.Socket;
/*
 * 这个类主要是用来处理新的线程，实现Runnable接口
 * 1：首先定一个构造方法，主要是为了初始化client对象
 * 2：同时重写run（）方法，这个方法主要开启新的方法用于 “ 读” 数据，和 “写” 数据的处理
 */

public class Task implements Runnable {

    private  Socket client;
    
    public Task(Socket client)
    {
        this.client=client;
    }

    @Override
    public void run() {
        try {
            handlerSocket();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void handlerSocket() throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(client.getInputStream()));  
        StringBuilder sb = new StringBuilder();  
        String temp;  
        int index;  
        while ((temp=br.readLine()) != null) {  
           System.out.println(temp);  
           if ((index = temp.indexOf("eof")) != -1) {//遇到eof时就结束接收  
            sb.append(temp.substring(0, index));  
               break;  
           }  
           sb.append(temp);  
        }  
        System.out.println("from client: " + sb);  
        //读完后写一句  
      Writer writer = new OutputStreamWriter(client.getOutputStream());  
        writer.write("Hello Client.");  
        writer.write("eof
");  
        writer.flush();  
        writer.close();  
        br.close();  
        client.close();  
        
    }

}

客户端

package oneServerForLotsClient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client {
    public static void main(String[] args) throws UnknownHostException, IOException {
        
        Socket client=new Socket("127.0.0.1", 6868);
        
        Writer writer=new OutputStreamWriter(client.getOutputStream());
        writer.write("Hello,Server. My name is client! ");
        writer.write("eof
");  
        writer.flush();
        
        
        //写完了就开始读
        
        BufferedReader reader=new BufferedReader(new InputStreamReader(client.getInputStream()));
        StringBuffer buffer=new StringBuffer();
        String temp;  
          int index;  
          while ((temp=reader.readLine()) != null) {  
             if ((index = temp.indexOf("eof")) != -1) {  
                buffer.append(temp.substring(0, index));  
                break;  
             }  
             buffer.append(temp);  
          }  
          System.out.println("from server: " + buffer);  
          writer.close();  
          reader.close();  
          client.close(); 
        
    }

}