NullPointerException Trying to Get RemoteIP (why?)

[Mike London]

I'm trying to get the client IP for one of the methods in the web service, but the stated directions I've found don't seem to work.

Here's what I've done...

At the @WebService level, I've defined these:

@HandlerChain(file="handler-chain.xml")

// Enable dependency injection on web service context.
@Resource
WebServiceContext wsContex

----

Then, in the web service method, I try to get the message context like this:

@WebMethod
public ....
{
MessageContext msgCtxt = wsContext.getMessageContext();
...

}

===

The handler-chsin.xml file has this:

 

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<javaee:handler-chains 
     xmlns:javaee="http://java.sun.com/xml/ns/javaee" 
     xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <javaee:handler-chain>
    <javaee:handler>
      <javaee:handler-class>net.myorg.ws.MessageHandler</javaee:handler-class>
    </javaee:handler>
  </javaee:handler-chain>
</javaee:handler-chains>

   

------

And the event MessageHandler code itself has this:

   
.
.
.
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import javax.xml.namespace.QName;
import javax.xml.soap.SOAPException;
import javax.xml.soap.SOAPMessage;
import javax.xml.ws.handler.MessageContext;
import javax.xml.ws.handler.soap.SOAPHandler;
import javax.xml.ws.handler.soap.SOAPMessageContext;

public class MessageHandler implements SOAPHandler<SOAPMessageContext>
{

    public boolean handleMessage(SOAPMessageContext ctx)
    {
        // Is this an inbound message, i.e., a request?
        Boolean response_p = (Boolean) ctx
                .get(MessageContext.MESSAGE_OUTBOUND_PROPERTY);

        // Manipulate the SOAP only if it's incoming.
        if (!response_p)
        {
            SOAPMessage msg = ctx.getMessage();
            Map m = (Map) ctx;
            dump_map(m, "");
        }
        return true; // continue down the chain
    }

    public boolean handleFault(SOAPMessageContext ctx)
    {
        return true; // do not continue down the chain
    }

    // For now, no-ops.
    public Set<QName> getHeaders()
    {
        return null;
    }

    public void close(MessageContext messageContext)
    {
    }

    private static void dump_map(Map map, String indent)
    {
        Set keys = map.keySet();
        for (Object key : keys)
        {
            System.out.println(indent + key + " ==> " + map.get(key));
            if (map.get(key) instanceof Map)
                dump_map((Map) map.get(key), indent += "   ");
        }
    }
}


 

=====================

However, each time I run this from the client side, I get a NullPointerException on the ' MessageContext msgCtxt = wsContext.getMessageContext();' line of code.

I thought the @Resource would dependency-inject the context....???

So, how do I correctly get the client's IP?

I can't seem to find the documentation beyond what I've done here.

Do I need to re-generate the client or other code? The web service itself is automatically deployed.

Thanks in advance.

Mike

[Mike London]

To clarify all the detail above, what I'm trying to do is the same thing as in this person's posting:

http://stackoverflow.com/questions/1641594/geting-the-ip-address-of-a-client-for-a-webservice

However, I get a NullPointerException on the line of code:

MessageContext mc = wsContext.getMessageContext();


Does anyone have....any ideas how to make this work?

Thanks.

-- M

[Ivan Krizsan]

Hi!
Your code does look correct. What web service stack are you deploying to?
An idea that may help you to determine whether injection of the WebServiceContext takes place is to implement a (non-public) setter method which takes a parameter of the type WebServiceContext and that is annotated with the @Resource annotation. In the method you can add some form of logging that prints a message and the reference to the WebServiceContext (and, of course, stores the reference in a suitable instance field).
Also make sure that you import the javax.xml.ws.WebServiceContext and no other interface or class.
Finally, for reference, you may want to take a look at section 5.3 in the JAX-WS 2.1 specification.
Best wishes!

[Mike London]

Hi Ivan,

Thanks for your great reply.

This is a simple JAX-WS web service running on Tomcat 6.0.20.

I like your idea about trying to verify the injection is happening, even though it seems it isn't.

Thanks!

Mike

[Ivan Krizsan]

Hi!
Since I finally have taken the time to install Metro into a Tomcat 6 installation, I tried to add the following in a Java-first endpoint implementation class:

...
private WebServiceContext mContext;

    @Resource
    private void setWSContext(WebServiceContext inContext)
    {
        System.out.println("***** Got the WS context: " + inContext);
        mContext = inContext;
    }
...

In a web service method I then added the code from the page you provided a link to - the code that is supposed to print the IP of the client.
Sad to say(?), there are no problems whatsoever; the WebServiceContext is injected when the web service is deployed/started and when there is a request to the operation in question, it does print the IP (127.0.0.1) from where the request came.
Have you tried to run your web service without the handler, to see if it is causing any problems?
Best wishes!

[Mike London]

Right, I got rid of all the handler logic since at least the injection into the web service should happen correctly.

I think I'll have to create a brand new example and, if it doesn't work, I'll post all the code here.

Thanks very much...hope you check out the ws code when I post it.

-- Mike

[Mike London]

Hey, just a thought here...

After I added the @Resource and the code to receive the context object, did I need to regenerate the web service or WSDL?

If so, that could be the problem.

- Mike

[Ivan Krizsan]

Hi!
I have only tried Java-first, without a WSDL or any deployment descriptors, on Tomcat 6 with Metro.
After having added the @Resource annotation, you definitely need to re-deploy the web service, but I cannot see how it would affect the WSDL.
If you don't have a WSDL, a new WSDL will be generated automatically when you deploy the web service.
Best wishes!

[Mike London]

Thanks. Appreciate your replies.

[Mike London]

I noticed when I added the @Resource element and re-deployed (using MyEclipse), the jaxws folder did not get updated on the server. I also tried re-creating the web service, but I still get the NullPointerException when I try to reference the context.

Hmmmm......

-- Mike