Jetty example source code file (LifeCycleCallback.java)

This example Jetty source code file (LifeCycleCallback.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Jetty tags/keywords

class, class, exception, illegalargumentexception, lifecyclecallback, lifecyclecallback, method, method, nosuchmethodexception, object, object, package, reflection, string

The Jetty LifeCycleCallback.java source code

//========================================================================
//$Id: LifeCycleCallback.java 1540 2007-01-19 12:24:10Z janb $
//Copyright 2006 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at 
//http://www.apache.org/licenses/LICENSE-2.0
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
//limitations under the License.
//========================================================================

package org.mortbay.jetty.plus.annotation;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

import org.mortbay.util.IntrospectionUtil;
import org.mortbay.util.Loader;



/**
 * LifeCycleCallback
 *
 *
 */
public abstract class LifeCycleCallback
{
    public static final Object[] __EMPTY_ARGS = new Object[] {};
    private Method _target;
    private Class _targetClass;
    
    
    public LifeCycleCallback()
    {
    }


    /**
     * @return the _targetClass
     */
    public Class getTargetClass()
    {
        return _targetClass;
    }


    /**
     * @param name the class to set
     */
    public void setTargetClass(Class clazz)
    {
        _targetClass = clazz;
    }
    
    
    /**
     * @return the target
     */
    public Method getTarget()
    {
        return _target;
    }

    /**
     * @param target the target to set
     */
    public void setTarget(Method target)
    {
        this._target = target;
    }
    
    
    

    public void setTarget (Class clazz, String methodName)
    {
        try
        {
            Method method = IntrospectionUtil.findMethod(clazz, methodName, null, true, true);
            validate(clazz, method);
            _target = method;
            _targetClass = clazz;
        }
        catch (NoSuchMethodException e)
        {
            throw new IllegalArgumentException ("Method "+methodName+" not found on class "+clazz.getName());
        }
    }


    
    
    public void callback (Object instance)
    throws Exception
    {
        if (getTarget() != null)
        {
            boolean accessibility = getTarget().isAccessible();
            getTarget().setAccessible(true);
            getTarget().invoke(instance, __EMPTY_ARGS);
            getTarget().setAccessible(accessibility);
        }
    }

    

    /**
     * Find a method of the given name either directly in the given
     * class, or inherited.
     * 
     * @param pack the package of the class under inspection
     * @param clazz the class under inspection
     * @param methodName the method to find 
     * @param checkInheritance false on first entry, true if a superclass is being introspected
     * @return
     */
    public Method findMethod (Package pack, Class clazz, String methodName, boolean checkInheritance)
    {
        if (clazz == null)
            return null;

        try
        {
            Method method = clazz.getDeclaredMethod(methodName, null);
            if (checkInheritance)
            {
                int modifiers = method.getModifiers();
                if (Modifier.isProtected(modifiers) || Modifier.isPublic(modifiers) || (!Modifier.isPrivate(modifiers)&&(pack.equals(clazz.getPackage()))))
                    return method;
                else
                    return findMethod(clazz.getPackage(), clazz.getSuperclass(), methodName, true);
            }
            return method;
        }
        catch (NoSuchMethodException e)
        {
            return findMethod(clazz.getPackage(), clazz.getSuperclass(), methodName, true);
        }
    }

    public boolean equals (Object o)
    {
        if (o==null)
            return false;
        if (!(o instanceof LifeCycleCallback))
            return false;
        LifeCycleCallback callback = (LifeCycleCallback)o;
        
        if (callback.getTargetClass()==null)
        {
            if (getTargetClass() != null)
                return false;
        }
        else if(!callback.getTargetClass().equals(getTargetClass()))
           return false;
        if (callback.getTarget()==null)
        {
            if (getTarget() != null)
                return false;
        }
        else if (!callback.getTarget().equals(getTarget()))
            return false;
        
        return true;
    }
    
    public abstract void validate (Class clazz, Method m);
}