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.json.annotation;
014
015import static java.lang.annotation.ElementType.*;
016import static java.lang.annotation.RetentionPolicy.*;
017
018import java.lang.annotation.*;
019
020import org.apache.juneau.annotation.*;
021
022/**
023 * Annotation for specifying various JSON options for the JSON serializers and parsers.
024 *
025 * <p>
026 * Can be used in the following locations:
027 * <ul>
028 *    <li>Marshalled classes/methods/fields.
029 *    <li><ja>@Rest</ja>-annotated classes and <ja>@RestOp</ja>-annotated methods when an {@link #on()} value is specified.
030 * </ul>
031 *
032 * <p>
033 * Can be used for the following:
034 * <ul class='spaced-list'>
035 *    <li>
036 *       Wrap bean instances inside wrapper object (e.g. <c>{'wrapperAttr':bean}</c>).
037 * </ul>
038 *
039 * <h5 class='section'>See Also:</h5><ul>
040 *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.JsonDetails">JSON Details</a>
041
042 * </ul>
043 */
044@Documented
045@Target({TYPE,METHOD,FIELD})
046@Retention(RUNTIME)
047@Inherited
048@Repeatable(JsonAnnotation.Array.class)
049@ContextApply(JsonAnnotation.Apply.class)
050public @interface Json {
051
052   /**
053    * Dynamically apply this annotation to the specified classes/methods/fields.
054    *
055    * <p>
056    * Used in conjunction with {@link org.apache.juneau.BeanContext.Builder#applyAnnotations(Class...)} to dynamically apply an annotation to an existing class/method/field.
057    * It is ignored when the annotation is applied directly to classes/methods/fields.
058    *
059    * <h5 class='section'>Valid patterns:</h5>
060    * <ul class='spaced-list'>
061    *  <li>Classes:
062    *       <ul>
063    *          <li>Fully qualified:
064    *             <ul>
065    *                <li><js>"com.foo.MyClass"</js>
066    *             </ul>
067    *          <li>Fully qualified inner class:
068    *             <ul>
069    *                <li><js>"com.foo.MyClass$Inner1$Inner2"</js>
070    *             </ul>
071    *          <li>Simple:
072    *             <ul>
073    *                <li><js>"MyClass"</js>
074    *             </ul>
075    *          <li>Simple inner:
076    *             <ul>
077    *                <li><js>"MyClass$Inner1$Inner2"</js>
078    *                <li><js>"Inner1$Inner2"</js>
079    *                <li><js>"Inner2"</js>
080    *             </ul>
081    *       </ul>
082    *    <li>Methods:
083    *       <ul>
084    *          <li>Fully qualified with args:
085    *             <ul>
086    *                <li><js>"com.foo.MyClass.myMethod(String,int)"</js>
087    *                <li><js>"com.foo.MyClass.myMethod(java.lang.String,int)"</js>
088    *                <li><js>"com.foo.MyClass.myMethod()"</js>
089    *             </ul>
090    *          <li>Fully qualified:
091    *             <ul>
092    *                <li><js>"com.foo.MyClass.myMethod"</js>
093    *             </ul>
094    *          <li>Simple with args:
095    *             <ul>
096    *                <li><js>"MyClass.myMethod(String,int)"</js>
097    *                <li><js>"MyClass.myMethod(java.lang.String,int)"</js>
098    *                <li><js>"MyClass.myMethod()"</js>
099    *             </ul>
100    *          <li>Simple:
101    *             <ul>
102    *                <li><js>"MyClass.myMethod"</js>
103    *             </ul>
104    *          <li>Simple inner class:
105    *             <ul>
106    *                <li><js>"MyClass$Inner1$Inner2.myMethod"</js>
107    *                <li><js>"Inner1$Inner2.myMethod"</js>
108    *                <li><js>"Inner2.myMethod"</js>
109    *             </ul>
110    *       </ul>
111    *    <li>Fields:
112    *       <ul>
113    *          <li>Fully qualified:
114    *             <ul>
115    *                <li><js>"com.foo.MyClass.myField"</js>
116    *             </ul>
117    *          <li>Simple:
118    *             <ul>
119    *                <li><js>"MyClass.myField"</js>
120    *             </ul>
121    *          <li>Simple inner class:
122    *             <ul>
123    *                <li><js>"MyClass$Inner1$Inner2.myField"</js>
124    *                <li><js>"Inner1$Inner2.myField"</js>
125    *                <li><js>"Inner2.myField"</js>
126    *             </ul>
127    *       </ul>
128    *    <li>A comma-delimited list of anything on this list.
129    * </ul>
130    *
131    * <h5 class='section'>See Also:</h5><ul>
132    *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
133    * </ul>
134    *
135    * @return The annotation value.
136    */
137   String[] on() default {};
138
139   /**
140    * Dynamically apply this annotation to the specified classes.
141    *
142    * <p>
143    * Identical to {@link #on()} except allows you to specify class objects instead of a strings.
144    *
145    * <h5 class='section'>See Also:</h5><ul>
146    *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
147    * </ul>
148    *
149    * @return The annotation value.
150    */
151   Class<?>[] onClass() default {};
152
153   /**
154    * Wraps beans in a JSON object with the specified attribute name.
155    *
156    * <p>
157    * Applies only to {@link ElementType#TYPE}.
158    *
159    * <p>
160    * This annotation can be applied to beans as well as other objects serialized to other types (e.g. strings).
161    *
162    * <h5 class='figure'>Example:</h5>
163    * <p class='bjava'>
164    *    <ja>@Json</ja>(wrapperAttr=<js>"myWrapper"</js>)
165    *    <jk>public class</jk> MyBean {
166    *       <jk>public int</jk> <jf>f1</jf> = 123;
167    *    }
168    * </p>
169    *
170    * <p>
171    * Without the <ja>@Json</ja> annotations, serializing this bean as JSON would have produced the following...
172    * <p class='bjson'>
173    *    {
174    *       f1: 123
175    *    }
176    * </p>
177    *
178    * <p>
179    * With the annotations, serializing this bean as JSON produces the following...
180    * <p class='bjson'>
181    *    {
182    *       myWrapper: {
183    *          f1: 123
184    *       }
185    *    }
186    * </p>
187    *
188    * @return The annotation value.
189    */
190   String wrapperAttr() default "";
191}