Question

我正在尝试使用java套接字编写聊天应用程序... 当客户端作为服务器的第一步进入时，概念是服务器在客户端端口上侦听存储为用户名和客户端的链接套接字为sockettuple（一个对象，其用户名为字符串，linksocket为socket） ..然后在存储之后发送客户端作为欢迎你连接..服务器监听listenthread和通信发生在单独的线程中..对于客户端创建套接字发生在主线程中并且写入服务器发生在单独的线程中在这里，套接字元组的存储很好但是在将消息从服务器发送到客户端Socketclosed exception时会发生服务器写入和客户端的读取线程......

// mainserver.java

import java.net.*;
import java.io.*;


class listenthread extends Thread{
ServerSocket mserver;
Socket link,targetsocket;
String user,targetuser;
sockettuple targettuple,starray[]= new sockettuple[10];


int i=0;

public listenthread(ServerSocket mserver){
try{
System.out.println("Inside Listenthread constructor");
 this.mserver=mserver;


}
catch (Exception e){
System.out.println("Exception inside listenthread constructor"+e);
}

}
public void  run(){
try{

 while(true){

 System.out.println("Listening.....");
 link=mserver.accept();

 System.out.println("Accepted");
 BufferedReader intosockb = new BufferedReader(new InputStreamReader(link.getInputStream()));
 user= intosockb.readLine();


 System.out.println(user + "Accepted");

 starray[i] =new sockettuple(link,user);
 i++;
 System.out.println(starray[i-1].username);

 new servwrite(link).start();
 
 intosockb.close();
 
 }

}
catch(Exception e){
System.out.println("Exception inside listenthread run "+e);
e.printStackTrace();
}
}
}


class servwrite extends Thread{ 
Socket link;

public servwrite(Socket link){
this.link=link;
}
public void run(){
try{
PrintStream fromserv=new PrintStream(link.getOutputStream());
 fromserv.print("You are  connected...Enter the target user:");
 
}
catch(Exception e){
System.out.println("Exception inside run of serv write thread..."+e);
}
}
}

public class mainserver {

public static void main(String args[]){
try{

ServerSocket Servermain= new ServerSocket(4579);

System.out.println(" Server main Socket created");

new listenthread(Servermain).start();




}
catch(Exception e){
System.out.println("Exception inside main "+e);
}

}
}



//Clientmenu.java

import java.net.*;
import java.io.*;

class clientread extends Thread{
Socket client;
BufferedReader key=null;
public clientread(Socket client){
try{
this.client=client;
 key= new BufferedReader(new InputStreamReader(client.getInputStream()));
}
catch(Exception e){
System.out.println("Exception inside client read thread's constructor");
e.printStackTrace();
}

}
public void run(){
try{
System.out.println("First line inside run of client read thread before cmsg readline");
String cmsg= key.readLine();
System.out.println(cmsg);
}
catch(Exception e){
System.out.println("Exception inside run of client read thread..."+e);
e.printStackTrace();
}
}
}

public  class Clientmenu {

   public static void main(String args[]){
   String user=" ";
   String targetuser="";
   Socket newclient;
   BufferedReader fromtheserv;

   try{
   
   newclient = new Socket("127.0.0.1",4579);
   System.out.print("Enter username:");
   BufferedReader key= new BufferedReader(new InputStreamReader(System.in));
       user=key.readLine();
       
       PrintStream fromclientp=new PrintStream(newclient.getOutputStream());
      fromclientp.print(user);
     

     new clientread(newclient).start();
   
   
       
  
  

   fromclientp.close();
   
   
     
   
   
           }
   
   catch(Exception e){
   System.out.println("Exception inside CLientmenu "+e);
   }
}
}

Answer 1

关闭＆＃34;缓冲读卡器＆＃34;在listenThread和＆＃34; PrintStream＆＃34;在clientMenu中导致问题。当您关闭返回的输入/输出流时，底层套接字也会关闭。

Refer to the documentation here

我希望这能解决问题。

Answer 2

'Socket closed'表示你关闭套接字，然后继续使用它。这是你代码中的一个错误。

请注意，不意味着对等方关闭连接。

您的代码存在许多问题，这里要查看的内容太多了。质量很差。我建议您掌握Java Tutorial的自定义网络路径并对其进行研究，并查看异常处理的最佳实践。目前，您只是捕获某些异常，记录它们，并继续，就像它们没有发生一样。 “catch”块之后的代码不应该依赖于“try”块中发生的事情。

Answer 3

尝试在listenthread类的run方法中删除此行。

intosockb.close();

正在关闭正在关闭套接字的流。

Java Socket异常套接字已关闭

3 个答案: