If a Tomcat server says "Client Aborted", and the client says "Premature EOF", who is right?

Question

I have a Tomcat server streaming data to a Java client over http. It is copying bytes from a file to HTTPServletResponse's outputstream in a servlet.

A client uses HttpURLConnection to connect and read the data.

Sometimes all is fine, other times both the client and server throw an exception.
The client says there is a "Premature EOF".
The server claims "ClientAbortException".

Isn't just one of the above possible?

CLIENT:

java.io.IOException: Premature EOF
       at sun.net.www.http.ChunkedInputStream.fastRead(ChunkedInputStream.java:234)
       at sun.net.www.http.ChunkedInputStream.read(ChunkedInputStream.java:662)
       at java.io.FilterInputStream.read(FilterInputStream.java:116)
       at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2669)
       at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2664)java.io.IOException: Premature EOF
       at sun.net.www.http.ChunkedInputStream.fastRead(ChunkedInputStream.java:234)
       at sun.net.www.http.ChunkedInputStream.read(ChunkedInputStream.java:662)
       at java.io.FilterInputStream.read(FilterInputStream.java:116)
       at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2669)
       at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2664)  

SERVER:

ClientAbortException:  java.io.IOException
    at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:358)
    at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:434)
    at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:349)
    at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:381)
    at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:370)
    at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:89)
    ...
Caused by: java.io.IOException
        at org.apache.coyote.ajp.AjpAprProcessor.flush(AjpAprProcessor.java:1223)
        at org.apache.coyote.ajp.AjpAprProcessor$SocketOutputBuffer.doWrite(AjpAprProcessor.java:1310)
        at org.apache.coyote.Response.doWrite(Response.java:560)
        at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:353)
        ... 23 more

Answer 1

They are not mutually exclusive.

This situation can and will occur if the socket is closed unexpectedly. For example, consider what would happen if your firewall just terminated the socket. From the server's point of view, when it tried to write data, the socket would appear closed, and the ClientAbortException would be triggered. From the client's point of view, the next read of bytes would fail, causing the premature end exception.

Answer 2

I was having similar problem while ago and I solved it by not using BufferedReader but reading one byte at a time and put the read in a try-catch for EOFException. Hope this helps.