001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.rest.annotation;
014
015import static java.lang.annotation.ElementType.*;
016import static java.lang.annotation.RetentionPolicy.*;
017
018import java.lang.annotation.*;
019
020import jakarta.servlet.http.*;
021
022import org.apache.juneau.http.response.*;
023
024/**
025 * Identifies a method that is called immediately after the <c>HttpServlet.service(HttpServletRequest, HttpServletResponse)</c>
026 * method is called.
027 *
028 * <p>
029 * Note that you only have access to the raw request and response objects at this point.
030 *
031 * <p>
032 * The list of valid parameter types are as follows:
033 * <ul>
034 *    <li>Servlet request/response objects:
035 *       <ul>
036 *          <li>{@link HttpServletRequest}
037 *          <li>{@link HttpServletResponse}
038 *       </ul>
039 * </ul>
040 *
041 * <h5 class='figure'>Example:</h5>
042 * <p class='bjava'>
043 *    <ja>@Rest</ja>(...)
044 *    <jk>public class</jk> MyResource <jk>extends</jk> BasicRestServlet {
045 *
046 *       <jc>// Add a request attribute to all incoming requests.</jc>
047 *       <ja>@RestStartCall</ja>
048 *       <jk>public void</jk> onStartCall(HttpServletRequest <jv>req</jv>) {
049 *          <jv>req</jv>.setAttribute(<js>"foobar"</js>, <jk>new</jk> FooBar());
050 *       }
051 *    }
052 * </p>
053 *
054 * <h5 class='section'>Notes:</h5><ul>
055 *    <li class='note'>
056 *       The method should return <jk>void</jk> although if it does return any value, the value will be ignored.
057 *    <li class='note'>
058 *       The method should be <jk>public</jk> although other visibilities are valid if the security manager allows it.
059 *    <li class='note'>
060 *       Static methods can be used.
061 *    <li class='note'>
062 *       Multiple start-call methods can be defined on a class.
063 *       <br>Start call methods on parent classes are invoked before start-call methods on child classes.
064 *       <br>The order of start-call method invocations within a class is alphabetical, then by parameter count, then by parameter types.
065 *    <li class='note'>
066 *       The method can throw any exception.
067 *       <br>{@link BasicHttpException BasicHttpExceptions} can be thrown to cause a particular HTTP error status code.
068 *       <br>All other exceptions cause an HTTP 500 error status code.
069 *    <li class='note'>
070 *       Note that if you override a parent method, you probably need to call <code><jk>super</jk>.parentMethod(...)</code>.
071 *       <br>The method is still considered part of the parent class for ordering purposes even though it's
072 *       overridden by the child class.
073 * </ul>
074 *
075 * <h5 class='section'>See Also:</h5><ul>
076 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrs.LifecycleHooks">Lifecycle Hooks</a>
077 * </ul>
078 */
079@Target({METHOD,TYPE})
080@Retention(RUNTIME)
081@Inherited
082@Repeatable(RestStartCallAnnotation.Array.class)
083public @interface RestStartCall {
084
085   /**
086    * Dynamically apply this annotation to the specified methods.
087    *
088    * <h5 class='section'>See Also:</h5><ul>
089    *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
090    * </ul>
091    *
092    * @return The annotation value.
093    */
094   String[] on() default {};
095}