/*
* ============================================================================
* GNU Lesser General Public License
* ============================================================================
*
* Beanlet - JSE Application Container.
* Copyright (C) 2006 Leon van Zantvoort
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*
* Leon van Zantvoort
* 243 Acalanes Drive #11
* Sunnyvale, CA 94086
* USA
*
* zantvoort@users.sourceforge.net
* http://beanlet.org
*/
package org.beanlet.demo;
import java.util.logging.Logger;
import org.beanlet.AroundInvoke;
import org.beanlet.Inject;
import org.beanlet.InvocationContext;
import org.beanlet.PostConstruct;
import org.beanlet.PreDestroy;
/**
* <p>This interceptor demonstrates basic interceptor functionality. Interceptor
* instances are always bound to a single beanlet instance. They can wrap
* lifecycle- and/or business methods.</p>
*
* <p>Similar to beanlets, interceptors support dependency injection.</p>
*
* @author Leon van Zantvoort
*/
public final class DemoInterceptor {
/**
* This logger instance is automatically injected by the container.
*/
@Inject
private Logger logger;
/**
* This method interceptors the beanlet's post-construct method. This method
* is invoked by the container if the underlying beanlet instance is to be
* initialized. The post-construct method of the underlying beanlet instance
* is called by invoking {@code ctx.proceed}. Any exceptions thrown by the
* that post-construct method are automatically thrown by this
* {@code proceed} invocation.
*
* @param ctx provides access to the invocation context currently active.
*/
@PostConstruct
public void init(InvocationContext ctx) throws Exception {
logger.info("Demo interceptor says: before-init");
try {
ctx.proceed();
} finally {
logger.info("Demo interceptor says: after-init");
}
}
/**
* This method intercepts business methods for which it is configured.
* If such business methods are invoked - either by container, or
* application - the container wraps this method around the call. The actual
* business method is invoked as result of calling {@code ctx.proceed}. This
* {@code proceed} method returns the result of the business method call, or
* returns {@code null} in case of a {@code void} method. If the business
* method throws an exception, it is propagated throuhh the {@code proceed}
* method.
*
* @param ctx provides access to the invocation context currently active.
*/
@AroundInvoke
public Object wrapMethod(InvocationContext ctx) throws Exception {
logger.info("Demo interceptor says: before");
try {
return ctx.proceed();
} finally {
logger.info("Demo interceptor says: after");
}
}
/**
* This method interceptors the beanlet's pre-destroy method. This method
* is invoked by the container if the underlying beanlet instance is to be
* destroyed. The pre-destroy method of the underlying beanlet instance is
* called by invoking {@code ctx.proceed}. Any exceptions thrown by the
* that pre-destroy method are automatically thrown by this {@code proceed}
* invocation.
*
* @param ctx provides access to the invocation context currently active.
*/
@PreDestroy
public void destroy(InvocationContext ctx) throws Exception {
logger.info("Demo interceptor says: before-destroy");
try {
ctx.proceed();
} finally {
logger.info("Demo interceptor says: after-destroy");
}
}
}