Apache Thrift: Throwing the exception thrown by the code executed in the method

Question

I'm working on a Thrift server which is basically just a wrapper around the Stanford Parser (although that's not too important). Sometimes the Stanford Parser will throw useful exceptions depending on the input it's given; for instance, if the input is too long (according to the parser), the user generating the input should receive this exception so they can decide how to handle it. However, I can't seem to get Thrift to pass this exception up, and instead only returns

Internal error processing <name of Thrift method being called>

to the client.

I have the following code in that method:

try
{
    // a whole bunch of Stanford Parser stuff
}
catch (Exception e)
{
    throw new TApplicationException(TApplicationException.INTERNAL_ERROR, e.getMessage());
}

and the method does throw a TApplicationException, but whatever the contents of e.getMessage() are are not being sent to the client. How can I get the exceptions being thrown by the Stanford Parser to be thrown by Thrift to the client?

In your thrift manifest did you specfy that the method can throw some exceptions? — darkheir, Feb 27 '13 at 08:37
I would recommend the answer to this related question: http://stackoverflow.com/questions/11755292/how-to-use-java-built-in-exception-in-thrift-idl — dhal, Feb 27 '13 at 20:02
Interesting...I had seen that question already but I didn't think that was what I was looking for. Maybe it is. And @darkheir, yes I have, but I've also tried taking that declaration out and it makes no difference. :/ — dmn, Feb 28 '13 at 19:28

freeman · Answer 1 · 2015-06-19T08:00:28.220

I am afraid you have to define your own exceptions, instead of using TException or any subclass of it.

That's because Thrift framework wrap your code like this(ProcessFunction.java):

try {
  result = getResult(iface, args);
} catch(TException tex) {
  LOGGER.error("Internal error processing " + getMethodName(), tex);
  TApplicationException x = new TApplicationException(TApplicationException.INTERNAL_ERROR, 
    "Internal error processing " + getMethodName());
  oprot.writeMessageBegin(new TMessage(getMethodName(), TMessageType.EXCEPTION, seqid));
  x.write(oprot);
  oprot.writeMessageEnd();
  oprot.getTransport().flush();
  return;
}

So, whatever message you give in TException, will be ignored and replaced by Thrift framework.

Apache Thrift: Throwing the exception thrown by the code executed in the method

1 Answers1