How to solve “Connection reset by peer: socket write error”?

问题

When I am reading the file content from server it returns the following error message:

Caused by: java.net.SocketException: Connection reset by peer: socket write error
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(Unknown Source)
at java.net.SocketOutputStream.write(Unknown Source)
at org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:215)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:462)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:366)
at org.apache.coyote.http11.InternalOutputBuffer$OutputStreamOutputBuffer.doWrite(InternalOutputBuffer.java:240)
at org.apache.coyote.http11.filters.ChunkedOutputFilter.doWrite(ChunkedOutputFilter.java:119)
at org.apache.coyote.http11.AbstractOutputBuffer.doWrite(AbstractOutputBuffer.java:192)
at org.apache.coyote.Response.doWrite(Response.java:504)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:383)
... 28 more

and my servlet program is

 response.setContentType("application/octet-stream");
 response.setHeader("Content-Disposition","attachment;filename="+filename);
 FileInputStream in = new FileInputStream(new File(filepath));
 ServletOutputStream output=response.getOutputStream();
 byte[] outputByte=new byte[4096];
 while(in.read(outputByte,0,4096)!=-1){
     output.write(outputByte,0,4096);//error indicates in this line
 }
 in.close();
 output.flush();
 output.close();

How to solve this issue?

回答1:

I've got the same exception and in my case the problem was in a renegotiation procecess. In fact my client closed a connection when the server tried to change a cipher suite. After digging it appears that in the jdk 1.6 update 22 renegotiation process is disabled by default. If your security constraints can effort this, try to enable the unsecure renegotiation by setting the sun.security.ssl.allowUnsafeRenegotiation system property to true. Here is some information about the process:

Session renegotiation is a mechanism within the SSL protocol that allows the client or the server to trigger a new SSL handshake during an ongoing SSL communication. Renegotiation was initially designed as a mechanism to increase the security of an ongoing SSL channel, by triggering the renewal of the crypto keys used to secure that channel. However, this security measure isn't needed with modern cryptographic algorithms. Additionally, renegotiation can be used by a server to request a client certificate (in order to perform client authentication) when the client tries to access specific, protected resources on the server.

Additionally there is the excellent post about this issue in details and written in (IMHO) understandable language.

回答2:

The socket has been closed by the client (browser).

A bug in your code:

byte[] outputByte=new byte[4096];
while(in.read(outputByte,0,4096)!=-1){
   output.write(outputByte,0,4096);
}

The last packet read, then write may have a length < 4096, so I suggest:

byte[] outputByte=new byte[4096];
int len;
while(( len = in.read(outputByte, 0, 4096 )) > 0 ) {
   output.write( outputByte, 0, len );
}

It's not your question, but it's my answer... ;-)

回答3:

The correct way to 'solve' it is to close the connection and forget about the client. The client has closed the connection while you where still writing to it, so he doesn't want to know you, so that's it, isn't it?

回答4:

It seems like your problem may be arising at

while(in.read(outputByte,0,4096)!=-1){

where it might go into an infinite loop for not advancing the offset (which is 0 always in the call). Try

while(in.read(outputByte)!=-1){

which will by default try to read upto outputByte.length into the byte[]. This way you dont have to worry about the offset. See FileInputStrem's read method