How to catch "Unable to sendViaPost to url"?

Question

I am running two axis2 services which communicate with each other. On every service startup I get this error:

2014-02-24 13:02:31,258 [INFO ]           HTTPSender  - Unable to sendViaPost to url[http://127.0.0.1:8081/axis2/services/MYSERVICE1.MYSERVICE1HttpSoap12Endpoint/]
java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:579)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.commons.httpclient.protocol.ReflectionSocketFactory.createSocket(ReflectionSocketFactory.java:140)
at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket(DefaultProtocolSocketFactory.java:125)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.open(MultiThreadedHttpConnectionManager.java:1361)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.axis2.transport.http.AbstractHTTPSender.executeMethod(AbstractHTTPSender.java:621)
at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:193)
at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:404)
at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:231)
at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:443)
at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:406)
at org.apache.axis2.description.OutInAxisOperationClient$NonBlockingInvocationWorker.run(OutInAxisOperation.java:446)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)

Since this error is not important, I would like to catch it and to print some better error message instead of the whole stack trace. Where do I catch this error?

Answer 1

Looking at the stack trace, I don't think you can catch it. Catching it would require that you own code somewhere in the Thread where the exception is being thrown.

Looking at the lowest stack in the trace shows this:

at java.lang.Thread.run(Thread.java:724)

To me this says that the exception is occurring in a thread most likely started by Axis. Because of this you can't catch it and show an error message.

If this is expected behavior, the best you can do is to configure your logging framework not to show INFOs from Axis. Be aware that this may mean you'll also miss more useful error messages as well.

All in all, I would focus on how to solve the "Unable to sendViaPost" from happening rather than suppressing the logging statement.

To answer your comment question: As you can see from the stack trace, the exception is not caught by any client code but is bubbled up to Thread itself. This is the stopping point for an Exception and where it stops. If you were going to catch it you'd have to have code in its call stack (which you don't, since when the thread is created by Axis a new call stack is created for the new thread Axis starts).

Read more here. The only difference in your case is that since the exception is not thrown on the main thread the program doesn't exit, but the thread where the exception occurs is terminated.

To sum it up: You have no code in the call stack and therefore cannot catch the exception. The only other option is to turn of INFO statements for Axis.