javax.interceptor.Interceptor Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of javax.interceptor-api Show documentation
Project GlassFish Interceptor API
There is a newer version: 1.2.2
Show newest version
/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2013 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package javax.interceptor;

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Specifies that a class is an interceptor.
 * 
 *  * @Interceptor
 * public class ValidationInterceptor { ... }
 * 
 * 
 * This annotation is optional if the
 * {@link javax.interceptor.Interceptors Interceptors} annotation or 
 * the EJB deployment descriptor are used to associate the 
 * interceptor with the target class. It is required when an
 * {@linkplain javax.interceptor.InterceptorBinding interceptor binding}
 * is used.
 * 
 * @see javax.interceptor.Interceptors
 *
 * @since Interceptors 1.1
 */
@Retention(RUNTIME)
@Target(TYPE)
@Documented
public @interface Interceptor {
    /**
     * Priorities that define the order in which interceptors are
     * invoked.  These values should be used with the
     * {@link javax.annotations.Priority Priority} annotation.
     * 

     * Interceptors defined by platform specifications should have 
     * priority values in the range PLATFORM_BEFORE 
     * up until LIBRARY_BEFORE, or starting at
     * PLATFORM_AFTER.  
     * 
Interceptors defined by extension libraries
     * should have priority values in the range LIBRARY_BEFORE
     * up until APPLICATION, or
     * LIBRARY_AFTER up until 
     * PLATFORM_AFTER.  
     * 
Interceptors defined by applications should have priority values in the range 
     * APPLICATION up until
     * LIBRARY_AFTER.  
     * 
     *
     * An interceptor that must be invoked before or
     * after another defined interceptor can choose any appropriate
     * value.
     *
     * Interceptors with smaller priority values are called first. If more than 
     * one interceptor has the same priority, the relative order of these interceptor 
     * is undefined.
     *
     * For example, an extension library might define an interceptor
     * like this:
     *
     *      * @Priority(Interceptor.Priority.LIBRARY_BEFORE+10)
     * @Interceptor
     * public class ValidationInterceptor { ... }
     * 
     *
     * @since Interceptors 1.2
     */
    public static class Priority {
	private Priority() { }	// don't allow instances

	/**
	 * Start of range for early interceptors defined by
	 * platform specifications.
	 */
	public static final int PLATFORM_BEFORE = 0;

	/**
	 * Start of range for early interceptors defined by
	 * extension libraries.
	 */
	public static final int LIBRARY_BEFORE = 1000;

	/**
	 * Start of range for interceptors defined by
	 * applications.
	 */
	public static final int APPLICATION = 2000;

	/**
	 * Start of range for late interceptors defined by
	 * extension libraries.
	 */
	public static final int LIBRARY_AFTER = 3000;

	/**
	 * Start of range for late interceptors defined by
	 * platform specifications.
	 */
	public static final int PLATFORM_AFTER = 4000;
    }
}