alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Struts example source code file (ObjectProfiler.java)

This example Struts source code file (ObjectProfiler.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 - Struts tags/keywords

class, illegalaccessexception, illegalargumentexception, invocationhandler, invocationhandler, object, object, objectprofiler, reflection, string, string, target, throwable, timerinvocationhandler, timerinvocationhandler

The Struts ObjectProfiler.java source code

/*
 * Copyright (c) 2002-2003, Atlassian Software Systems Pty Ltd All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *     * Neither the name of Atlassian Software Systems Pty Ltd nor the names of
 * its contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.opensymphony.xwork2.util.profiling;

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

/**
 * @author <a href="mailto:scott@atlassian.com">Scott Farquhar
 */
public class ObjectProfiler
{

    /**
     * Given a class, and an interface that it implements, return a proxied version of the class that implements
     * the interface.
     * <p>
     * The usual use of this is to profile methods from Factory objects:
     * <pre>
     * public PersistenceManager getPersistenceManager()
     * {
     *   return new DefaultPersistenceManager();
     * }
     *
     * instead write:
     * public PersistenceManager getPersistenceManager()
     * {
     *   return ObjectProfiler.getProfiledObject(PersistenceManager.class, new DefaultPersistenceManager());
     * }
     * </pre>
     * <p>
     * A side effect of this is that you will no longer be able to downcast to DefaultPersistenceManager.  This is probably a *good* thing.
     *
     * @param interfaceClazz    The interface to implement.
     * @param o                 The object to proxy
     * @return                  A proxied object, or the input object if the interfaceClazz wasn't an interface.
     */
    public static Object getProfiledObject(Class interfaceClazz, Object o)
    {
        //if we are not active - then do nothing
        if (!UtilTimerStack.isActive())
            return o;

        //this should always be true - you shouldn't be passing something that isn't an interface
        if (interfaceClazz.isInterface())
        {
            InvocationHandler timerHandler = new TimerInvocationHandler(o);
            return Proxy.newProxyInstance(interfaceClazz.getClassLoader(),
                    new Class[]{interfaceClazz}, timerHandler);
        }
        else
        {
            return o;
        }
    }

    /**
     * A profiled call {@link Method#invoke(java.lang.Object, java.lang.Object[])}. If {@link UtilTimerStack#isActive() }
     * returns false, then no profiling is performed.
     */
    public static Object profiledInvoke(Method target, Object value, Object[] args) throws IllegalAccessException, InvocationTargetException
    {
        //if we are not active - then do nothing
        if (!UtilTimerStack.isActive())
            return target.invoke(value, args);

        String logLine = new String(getTrimmedClassName(target) + "." + target.getName() + "()");

        UtilTimerStack.push(logLine);
        try
        {
            Object returnValue = target.invoke(value, args);

            //if the return value is an interface then we should also proxy it!
            if (returnValue != null && target.getReturnType().isInterface())
            {
//                System.out.println("Return type " + returnValue.getClass().getName() + " is being proxied " + target.getReturnType().getName() + " " + logLine);
                InvocationHandler timerHandler = new TimerInvocationHandler(returnValue);
                return Proxy.newProxyInstance(returnValue.getClass().getClassLoader(),
                        new Class[]{target.getReturnType()}, timerHandler);
            }
            else
            {
                return returnValue;
            }
        }
        finally
        {
            UtilTimerStack.pop(logLine);
        }
    }

    /**
     * Given a method, get the Method name, with no package information.
     */
    public static String getTrimmedClassName(Method method)
    {
        String classname = method.getDeclaringClass().getName();
        return classname.substring(classname.lastIndexOf('.') + 1);
    }

}

class TimerInvocationHandler implements InvocationHandler
{
    protected Object target;

    public TimerInvocationHandler(Object target)
    {
        if (target == null)
            throw new IllegalArgumentException("Target Object passed to timer cannot be null");
        this.target = target;
    }

    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
    {
        return ObjectProfiler.profiledInvoke(method, target, args);
    }

}

Other Struts examples (source code examples)

Here is a short list of links related to this Struts ObjectProfiler.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.