Handler to add HTTP headers to HTTP request not invoked when using Axis Client API

Question

I am using the Axis API to access Axis HTTP server. The documentation of the API can be found here.

I am using the following code to add handlers to the server. service is of type java.xml.rpc.Service

    HandlerRegistry registry = service.getHandlerRegistry();
    QName serviceName = new QName(url, "MyServiceClass");

    List<HandlerInfo> handlerChain = new ArrayList<HandlerInfo>();
    HandlerInfo handlerInfo = new HandlerInfo(MyHandler.class, null, null);
    handlerChain.add(handlerInfo);
    registry.setHandlerChain(serviceName, handlerChain);

I know that the service name is correct as I am getting the correct output in subsequent calls to the service object.

Somehow the handler is not being invoked. Here is the Handler class. My intention is to add custom headers to the HTTP request before forwarding the request to the server.

import javax.xml.namespace.QName;
import org.apache.axis.AxisFault;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;

public class MyHandler extends BasicHandler {

    @Override
    public void init() {
        System.out.println("init called");
        super.init();
        System.out.println("init called");
    }

    @Override
    public void cleanup() {
        super.cleanup();
        System.out.println("cleanup called");
    }

    @Override
    public void invoke(MessageContext mc) throws AxisFault {
        System.out.println("invoke called");
    }

    public QName[] getHeaders() {
        System.out.println("getHeaders");
        return new QName[1];
    }
}

What is wrong with the above code?

Is there any other way to modify HTTP Headers using Apache Axis API?

Answer 1

Okie. This should do the trick :

1 - Create a wsdd file (say /tmp/test.wsdd) containing this :

<deployment xmlns="http://xml.apache.org/axis/wsdd/" xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">
 <handler name="test" type="java:axistest.TestHandler" />
 <transport name="http" pivot="java:org.apache.axis.transport.http.HTTPSender">
   <requestFlow>
    <handler type="test"/>
   </requestFlow>
 </transport>
</deployment>

2 - Ensure all axis libs are in your class path and then run :

java org.apache.axis.utils.Admin client /tmp/test.wsdd

3 - Step 2 will generate a client-config.wsdd. Copy this to your project and ensure it will be in the class path when the project is run.

4 - ALL webservice calls (via Http transport) will route via the TestHandler1 class

Here is my TestHandler1 class (a slight modification of ur handler to access the MIME headers) :

package axistest;

import javax.xml.namespace.QName;
import javax.xml.soap.MimeHeaders;
import org.apache.axis.AxisFault;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;

public class TestHandler1 extends BasicHandler {

@Override
public void init() {
    System.out.println("init called");
    super.init();
    System.out.println("init called");
}

@Override
public void cleanup() {
    super.cleanup();
    System.out.println("cleanup called");
}

@Override
public void invoke(MessageContext mc) throws AxisFault {
    System.out.println("invoke called");
    System.out.println("=----------------------------------=");
    MimeHeaders mimeHeaders = mc.getMessage().getMimeHeaders();
    mimeHeaders.addHeader("X-Test", "Hello");
    System.out.println("Headers : \n " + mimeHeaders);
}

public QName[] getHeaders() {
    System.out.println("getHeaders");
    return new QName[1];
}

}

when I run this on my box, I see that these handler methods are being invoked :

- Unable to find required classes (javax.activation.DataHandler and javax.mail.internet.MimeMultipart). Attachment support is disabled.
init called
init called
invoke called
=----------------------------------=
Headers : 
 org.apache.axis.message.MimeHeaders@761eec35
.
.
.