I am trying to implement an HTTP Server using Sockets. If the Client (For example a browser) requests a directory the server displays a list of available files. The problem arises when the client is requesting a file. I get the following error:
java.net.SocketException: Connection reset by peer: socket write error
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113)
at java.net.SocketOutputStream.write(SocketOutputStream.java:159)
at cf.charly1811.java.web.RequestHandler.writeFile(RequestHandler.java:152)
at cf.charly1811.java.web.RequestHandler.processRequest(RequestHandler.java:139)
at cf.charly1811.java.web.RequestHandler.handleRequest(RequestHandler.java:110)
at cf.charly1811.java.web.RequestHandler.run(RequestHandler.java:86)
at java.lang.Thread.run(Thread.java:745)
The stacktrace shows that the problem is coming from the writeFile()
methods:
private void writeFile(File request) throws IOException
{
InputStream byteReader = new BufferedInputStream(new FileInputStream(request));
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = byteReader.read(buffer)) != -1)
{
outputStream.write(buffer, 0, bytesRead);
}
byteReader.close();
}
But I can't figure out what's wrong. Can you help me?
EDIT
Thanks everyone for your answers. After I read your answers I understood that the problem was that the Socket when an error occured. Here's was my wrong code:
// Method to process a single request
handleRequest() throw IOException
{
// process here
// if the client request a file
writeFile();
// close socket when the request is processed
}
// The method is called
public run()
{
try{
// If an error occurs the try/catch won't be called because it is implemented outside the loop. So when an IOException occurs, the loop just stop and exit the program
while(true)
{
handleRequest();
}
}
catch(IOException e) {
// Handle exception here
}
}
And my new code was looking like this:
// Method to process a single request
handleRequest()
{
try {
// process here
// if the client request a file
writeFile();
// close socket when the request is processed
}
// If this exception occurs the catch() method will be called
catch(IOException e)
{
// handle exception here
}
}
// The method is called
public run()
{
while(true)
{
handleRequest();
}
}
}
It is possible for the TCP socket to be "closing" and your code to not have yet been notified.
Here is a animation for the life cycle. http://tcp.cs.st-andrews.ac.uk/index.shtml?page=connection_lifecycle
Basically, the connection was closed by the client. You already have throws IOException
and SocketException
extends IOException
. This is working just fine. You just need to properly handle IOException
because it is a normal part of the api.
EDIT: The RST
packet occurs when a packet is received on a socket which does not exist or was closed. There is no difference to your application. Depending on the implementation the reset
state may stick and closed
will never officially occur.