Java多线程-----Socket通信

最新推荐文章于 2021-02-16 08:48:31 发布

原创最新推荐文章于 2021-02-16 08:48:31 发布 · 3.2k 阅读

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文章标签：

#多线程 #java #socket #import #string #server

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该博客介绍了一个基于Java的多线程Socket通信程序，包含Server和Client端。服务器端监听端口，有客户端连接时创建两个线程处理；客户端连接后也创建两个线程实现信息收发。程序基本通信正常，但存在一些bug，如客户端用Ctrl+C结束时服务器收到null，关闭部分客户端后线程未关闭等。

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程序分Server和Client

服务器端打开侦听的端口，一有客户端连接就创建两个新的线程来负责这个连接

一个负责客户端发送的信息(ClientMsgCollectThread 类)，

另一个负责通过该Socket发送数据（ServerMsgSendThread ）

Server.java代码如下:

/*
* 创建日期 2005-7-7
*
* TODO 要更改此生成的文件的模板，请转至
* 窗口－首选项－ Java －代码样式－代码模板
*/
package person.fane.MutiUser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

/**
* 服务器端
*
* @author Fane
*/
public class Server extends ServerSocket {

private static final int SERVER_PORT = 10000;

/**
* 构造方法，用于实现连接的监听
*
* @throws IOException
*/
public Server() throws IOException {
super(SERVER_PORT);

  try {
   while (true) {
    Socket socket = super.accept();

    new Thread(new ClientMsgCollectThread(socket), "getAndShow"
      + socket.getPort()).start();
    new Thread(new ServerMsgSendThread(socket), "send"
      + socket.getPort()).start();

   }
  } catch (IOException e) {
   e.printStackTrace();
  }

}

public static void main(String[] args) throws IOException {
new Server();
}

/**
* 该类用于创建接收客户端发来的信息并显示的线程
*
* @author Fane
* @version 1.0.0
*/
class ClientMsgCollectThread implements Runnable {

private Socket client;

private BufferedReader in;

private StringBuffer inputStringBuffer = new StringBuffer("Hello");

  /**
   * 得到Socket的输入流
   *
   * @param s
   * @throws IOException
   */
  public ClientMsgCollectThread(Socket s) throws IOException {
   client = s;

   in = new BufferedReader(new InputStreamReader(client
     .getInputStream(), "GBK"));
  }

public void run() {
try {

    while (!client.isClosed()) {
     inputStringBuffer.delete(0, inputStringBuffer.length());
     inputStringBuffer.append(in.readLine());

     System.out.println(getMsg(inputStringBuffer.toString()));
    }
   } catch (IOException e) {
    //e.printStackTrace();
    System.out.println(client.toString() + " is closed!");

}
}

  /**
   * 构造显示的字符串
   *
   * @param line
   * @return
   */
  private String getMsg(String line) {
   return client.toString() + " says:" + line;
  }

}

/**
* 该类用于创建发送数据的线程
*
* @author Fane
* @version 1.0.0
*/
class ServerMsgSendThread implements Runnable {

private Socket client;

private PrintWriter out;

private BufferedReader keyboardInput;

private StringBuffer outputStringBuffer = new StringBuffer("Hello");

  /**
   * 得到键盘的输入流
   *
   * @param s
   * @throws IOException
   */
  public ServerMsgSendThread(Socket s) throws IOException {
   client = s;

out = new PrintWriter(client.getOutputStream(), true);
keyboardInput = new BufferedReader(new InputStreamReader(System.in));

}

public void run() {
try {

    while (!client.isClosed()) {
     outputStringBuffer.delete(0, outputStringBuffer.length());
     outputStringBuffer.append(keyboardInput.readLine());

     out.println(outputStringBuffer.toString());
    }
   } catch (IOException e) {
    //e.printStackTrace();
    System.out.println(client.toString() + " is closed!");

}
}

}

客户端：

实现基于IP地址的连接，连接后也创建两个线程来实现信息的发送和接收

/*
* 创建日期 2005-7-7
*
*/
package person.fane.MutiUser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/**
* 客户端
*
* @author Fane
*/
public class Client {

private Socket mySocket;

/**
* 创建线程的构造方法
*
* @param IP
* @throws IOException
*/
public Client(String IP) throws IOException {

  try {
   mySocket = new Socket(IP, 10000);
   new Thread(new ServerMsgCollectThread(mySocket), "getAndShow"
     + mySocket.getPort()).start();
   new Thread(new ClientMsgSendThread(mySocket), "send"
     + mySocket.getPort()).start();

  } catch (IOException e) {
   //e.printStackTrace();
   System.out.println("Server.IP:" + IP
     + " port:10000 can not be Connected");
  }
}

public static void main(String[] args) throws IOException {
  try {
   new Client(args[0]);
  } catch (Exception e) {
   System.out.println("输入的IP地址错误");
  }
}

/**
* 该类用于创建接收服务端发来的信息并显示的线程
*
* @author Fane
* @version 1.0.0
*/
class ServerMsgCollectThread implements Runnable {

private Socket client;

private BufferedReader in;

private StringBuffer inputStringBuffer = new StringBuffer("Hello");

  /**
   * 得到Socket的输入流
   *
   * @param s
   * @throws IOException
   */
  public ServerMsgCollectThread(Socket s) throws IOException {
   client = s;

   in = new BufferedReader(new InputStreamReader(client
     .getInputStream(), "GBK"));
  }

public void run() {
try {

    while (!client.isClosed()) {
     inputStringBuffer.delete(0, inputStringBuffer.length());
     inputStringBuffer.append(in.readLine());
     System.out.println(getMsg(inputStringBuffer.toString()));
    }
   } catch (IOException e) {
    //e.printStackTrace();
    System.out.println(client.toString() + " is closed!");
    System.exit(0);
   }
  }

  /**
   * 构造输入字符串
   *
   * @param line
   * @return
   */
  private String getMsg(String line) {
   return client.toString() + " says:" + line;
  }

}

/**
* 该类用于创建发送数据的线程
*
* @author Fane
* @version 1.0.0
*/
class ClientMsgSendThread implements Runnable {

private Socket client;

private PrintWriter out;

private BufferedReader keyboardInput;

private StringBuffer outputStringBuffer = new StringBuffer("Hello");

  /**
   * 得到键盘的输入流
   *
   * @param s
   * @throws IOException
   */
  public ClientMsgSendThread(Socket s) throws IOException {
   client = s;

out = new PrintWriter(client.getOutputStream(), true);
keyboardInput = new BufferedReader(new InputStreamReader(System.in));

}

public void run() {
try {

    while (!client.isClosed()) {
     outputStringBuffer.delete(0, outputStringBuffer.length());
     outputStringBuffer.append(keyboardInput.readLine());

     out.println(outputStringBuffer.toString());
    }
    out.println("--- See you, bye! ---");
   } catch (IOException e) {
    //e.printStackTrace();
    System.out.println(client.toString() + " is closed!");
    System.exit(0);
   }
  }

}

该程序基本通信没有问题

但是有如下bug,请各位提出宝贵意见

1：在cmd模式下，用Ctrl+C来结束客户端程序，服务器先出现收到为null，再出现断开连接的提示，在直接关闭命令行时就只提示断开连接，不知道这个null何来

Socket[addr=/192.168.0.12,port=2205,localport=10000] says:null
Socket[addr=/192.168.0.12,port=2205,localport=10000] is closed!

2：假如打开5个命令行并连接成功后，发送信息时，服务器能收到所有5个客户端来的信息，但是5个客户端只能轮流收到服务器的信息，也就是说我每打一个"Hello"+Enter,只有一个客户端能收到消息，重复5次，这样每个客户端都能收到一次，这个本不奇怪(设计的问题，不好意思)，但是我关闭了其中4个以后，还是要发5次客户端才能收到一次消息，也就是说其他4个Socket关闭了，但是线程没有关闭，不知道怎样才能解决线程的这个问题(在一台机子上试验出现这个问题)

发送：

Socket[addr=/192.168.0.12,port=2201,localport=10000] is closed!
Socket[addr=/192.168.0.12,port=2203,localport=10000] says:null
Socket[addr=/192.168.0.12,port=2203,localport=10000] is closed!
Socket[addr=/192.168.0.12,port=2204,localport=10000] says:null
Socket[addr=/192.168.0.12,port=2204,localport=10000] is closed!
Socket[addr=/192.168.0.12,port=2205,localport=10000] says:null
Socket[addr=/192.168.0.12,port=2205,localport=10000] is closed!

hehhe
hehe
hehe
hehe
hehe

接收：Socket[addr=/192.168.0.12,port=10000,localport=2206] says:hehe

(前面4个hehe丢失了)

其它bug也在查找中.......