Registering a custom ResourceMethodInvocationHandler in Jersey

Question

I am attempting to intercept a resource call after it's JSON has been unmarshalled. Reading through some forums and posts I discovered that I may be able to do so by implementing org.glassfish.jersey.server.spi.internal.ResourceMethodInvocationHandlerProvider. Having done so I am now stuck trying to get my CustomResourceMethodInvocationHandler provider registered so that the jersey/hk2 internals call my overridden public InvocationHandler create(Invocable invocable) method. Any help would be much appreciated!

Answer 1

Let's have a look at this approach:

(Tested with Jersey 2.10 and JSON serialization)

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

1) Implement a custom ResourceMethodInvocationHandlerProvider

package com.example.handler;

import java.lang.reflect.InvocationHandler;

import org.glassfish.jersey.server.model.Invocable;
import org.glassfish.jersey.server.spi.internal.ResourceMethodInvocationHandlerProvider;

public class CustomResourceInvocationHandlerProvider implements
        ResourceMethodInvocationHandlerProvider {

    @Override
    public InvocationHandler create(Invocable resourceMethod) {
            return new MyIncovationHandler();
    }

}

---

2) Implement a custom InvocationHandler

package com.example.handler;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

public class MyIncovationHandler implements InvocationHandler {

    @Override
    public Object invoke(Object obj, Method method, Object[] args)
            throws Throwable {
        // optionally add some logic here
        Object result = method.invoke(obj, args);
        return result;
    }
}

---

3) Create a custom Binder class and register your CustomResourceInvocationHandlerProvider

package com.example.handler;

import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.server.spi.internal.ResourceMethodInvocationHandlerProvider;

public class CustomBinder extends AbstractBinder {

    @Override
    protected void configure() {
        // this is where the magic happens!
        bind(CustomResourceInvocationHandlerProvider.class).to(
                ResourceMethodInvocationHandlerProvider.class);
    }
}

---

4) Optionally: Set breakpoint in ResourceMethodInvocationHandlerFactory

Just to understand how the selection of ResourceMethodInvocationHandlerProvider in org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory works.

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

As you can see, the most important thing is to bind your CustomResourceInvocationHandlerProvider.class to the ResourceMethodInvocationHandlerProvider.class. After doing this, HK2 knows about your Provider and also about your Handler!

Hope, I could help.