线程“主”异常java.net.SocketException：连接重置 -

Question

我已经创建了一个简单的客户端/服务器程序，其中客户端从命令行参数中获取文件。客户端然后将文件发送到服务器，在那里使用GZIP进行压缩并发送回客户端。

服务器程序首次运行时很好，并且不会产生错误，但运行客户端后出现错误。

我得到一个错误，说连接重置，我试过很多不同的端口，所以我想知道如果我的代码有问题或者我关闭了流的时间？

任何帮助将不胜感激！

编辑 - 对两个程序进行了更改。

客户：

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

//JZip Client 

public class NetZip { 

    //Declaring private variables. 
    private Socket socket = null; 
    private static String fileName = null; 
    private File file = null; 
    private File newFile = null; 
    private DataInputStream fileIn = null; 
    private DataInputStream dataIn = null; 
    private DataOutputStream dataOut = null; 
    private DataOutputStream fileOut = null; 


    public static void main(String[] args) throws IOException { 
    try { 
     fileName = args[0]; 
     } 
    catch (ArrayIndexOutOfBoundsException error) { 
     System.out.println("Please Enter a Filename!"); 
    } 
    NetZip x = new NetZip(); 
    x.toServer(); 
    x.fromServer(); 

    } 

    public void toServer() throws IOException{ 
    while (true){ 
    //Creating socket 
     socket = new Socket("localhost", 4567); 
     file = new File(fileName); 

     //Creating stream to read from file. 
     fileIn = new DataInputStream(
      new BufferedInputStream(
       new FileInputStream(
        file))); 

     //Creating stream to write to socket. 
     dataOut = new DataOutputStream(
      new BufferedOutputStream(
       socket.getOutputStream())); 

     byte[] buffer = new byte[1024]; 

      int len; 
      //While there is data to be read, write to socket. 
     while((len = fileIn.read(buffer)) != -1){ 
      try{ 
      System.out.println("Attempting to Write " + file 
       + "to server."); 
      dataOut.write(buffer, 0, len); 
      } 
      catch(IOException e){ 
      System.out.println("Cannot Write File!"); 
      } 
      } 
     fileIn.close(); 
     dataOut.flush(); 
     dataOut.close(); 

     } 

    } 
    //Read data from the serversocket, and write to new .gz file. 
    public void fromServer() throws IOException{ 

    dataIn = new DataInputStream(
      new BufferedInputStream(
        socket.getInputStream())); 

    fileOut = new DataOutputStream(
      new BufferedOutputStream(
       new FileOutputStream(
        newFile))); 

    byte[] buffer = new byte[1024]; 

     int len; 
     while((len = dataIn.read(buffer)) != -1){ 
      try { 
      System.out.println("Attempting to retrieve file.."); 
      fileOut.write(buffer, 0, len); 
      newFile = new File(file +".gz"); 

      } 
      catch (IOException e){ 
      System.out.println("Cannot Recieve File"); 
      } 
     } 
     dataIn.close(); 
     fileOut.flush(); 
     fileOut.close(); 
     socket.close(); 

    } 


} 

服务器：

import java.io.*; 
import java.net.*; 
import java.util.zip.GZIPOutputStream; 

//JZip Server 

public class ZipServer { 

    private ServerSocket serverSock = null; 
    private Socket socket = null; 
    private DataOutputStream zipOut = null; 
    private DataInputStream dataIn = null; 

    public void zipOut() throws IOException { 

    //Creating server socket, and accepting from other sockets. 
    try{ 
    serverSock = new ServerSocket(4567); 
    socket = serverSock.accept(); 
    } 
    catch(IOException error){ 
     System.out.println("Error! Cannot create socket on port"); 
    } 

    //Reading Data from socket 
    dataIn = new DataInputStream(
      new BufferedInputStream(
        socket.getInputStream())); 

    //Creating output stream. 
    zipOut= new DataOutputStream(
     new BufferedOutputStream(
      new GZIPOutputStream(
       socket.getOutputStream()))); 

    byte[] buffer = new byte[1024]; 

     int len; 
     //While there is data to be read, write to socket. 
     while((len = dataIn.read(buffer)) != -1){ 
      System.out.println("Attempting to Compress " + dataIn 
       + "and send to client"); 
      zipOut.write(buffer, 0, len); 
     } 
     dataIn.close(); 
     zipOut.flush(); 
     zipOut.close(); 
     serverSock.close(); 
     socket.close(); 
    } 

    public static void main(String[] args) throws IOException{ 
    ZipServer run = new ZipServer(); 
    run.zipOut(); 

    } 

} 

错误消息：

Exception in thread "main" java.net.SocketException: Connection reset 
    at java.net.SocketInputStream.read(SocketInputStream.java:196) 
    at java.net.SocketInputStream.read(SocketInputStream.java:122) 
    at java.io.BufferedInputStream.fill(BufferedInputStream.java:235) 
    at java.io.BufferedInputStream.read1(BufferedInputStream.java:275) 
    at java.io.BufferedInputStream.read(BufferedInputStream.java:334) 
    at java.io.DataInputStream.read(DataInputStream.java:100) 
    at ZipServer.<init>(ZipServer.java:38) 
    at ZipServer.main(ZipServer.java:49) 

Answer 1

首先，因为客户端失败和发送任何数据之前结束，所以所发生的错误 连接在服务器想要读取时关闭。因为您指定的文件对象未使用的局部变量（没有你的编译器没有发出警告？）

public File file = null; 
public File newFile = null; 

public static void main(String[] args) throws IOException { 
try { 
    String fileName = args[0]; 
    File file = new File(fileName); 
    File newFile = new File(file +".gz"); 
    } 
catch (ArrayIndexOutOfBoundsException error) { 
    System.out.println("Please Enter a Filename!"); 
} 

但在你toServer方法使用类变量文件作为参数的FileInputStream和这个变量为空时
错误这会导致程序结束的错误。

第二，如果你完成了写入OutputStream的，你应该叫

socket.shtdownOutput(); 

否则，服务器尝试读取，直到发生超时。