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.http.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.*;
021import org.apache.juneau.httppart.*;
022import org.apache.juneau.oapi.*;
023
024/**
025 * REST request form-data annotation.
026 *
027 * <p>
028 * Identifies a POJO to be used as a form-data entry on an HTTP request.
029 *
030 * <p>
031 * Can be used in the following locations:
032 * <ul>
033 *    <li>Arguments and argument-types of server-side <ja>@RestOp</ja>-annotated methods.
034 *    <li>Arguments and argument-types of client-side <ja>@RemoteResource</ja>-annotated interfaces.
035 *    <li>Methods and return types of server-side and client-side <ja>@Request</ja>-annotated interfaces.
036 * </ul>
037 *
038 * <h5 class='topic'>Arguments and argument-types of server-side @RestOp-annotated methods</h5>
039 * <p>
040 * Annotation that can be applied to a parameter of a <ja>@RestOp</ja>-annotated method to identify it as a form-data parameter.
041 *
042 * <h5 class='section'>Example:</h5>
043 * <p class='bjava'>
044 *    <ja>@RestPost</ja>
045 *    <jk>public void</jk> doPost(
046 *          <ja>@FormData</ja>(<js>"p1"</js>) <jk>int</jk> <jv>p1</jv>,
047 *          <ja>@FormData</ja>(<js>"p2"</js>) String <jv>p2</jv>,
048 *          <ja>@FormData</ja>(<js>"p3"</js>) UUID <jv>p3</jv>
049 *       ) {...}
050 * </p>
051 *
052 * <p>
053 * This is functionally equivalent to the following code...
054 * <p class='bjava'>
055 *    <ja>@RestPost</ja>
056 *    <jk>public void</jk> doPost(RestRequest <jv>req</jv>) {
057 *       <jk>int</jk> <jv>p1</jv> = <jv>req</jv>.getFormParam(<js>"p1"</js>).as(<jk>int</jk>.<jk>class</jk>).orElse(0);
058 *       String <jv>p2</jv> = <jv>req</jv>.getFormParam(<js>"p2"</js>).asString().orElse(<jk>null</jk>);
059 *       UUID <jv>p3</jv> = <jv>req</jv>.getFormParam(<js>"p3"</js>).as(UUID.<jk>class</jk>).orElse(<jk>null</jk>);
060 *       ...
061 *    }
062 * </p>
063 *
064 * <h5 class='section'>See Also:</h5><ul>
065 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrs.Swagger">Swagger</a>
066 *    <li class='extlink'><a class='doclink' href='https://swagger.io/specification/v2#parameterObject'>Swagger Parameter Object</a>
067 * </ul>
068 *
069 * <h5 class='topic'>Important note concerning FORM posts</h5>
070 * <p>
071 * This annotation should not be combined with the {@link Content @Content} annotation or <c>RestRequest.getContent()</c> method
072 * for <c>application/x-www-form-urlencoded POST</c> posts, since it will trigger the underlying servlet
073 * API to parse the body content as key-value pairs resulting in empty content.
074 *
075 * <p>
076 * The {@link Query @Query} annotation can be used to retrieve a URL parameter in the URL string without triggering the
077 * servlet to drain the body content.
078 *
079 * <h5 class='topic'>Arguments and argument-types of client-side @RemoteResource-annotated interfaces</h5>
080 * <p>
081 * Annotation applied to Java method arguments of interface proxies to denote that they are FORM post parameters on the
082 * request.
083 *
084 * <h5 class='section'>See Also:</h5><ul>
085 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrc.FormData">@FormData</a>
086 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrc.Request">@Request</a>
087 * </ul>
088 *
089 * <h5 class='topic'>Methods and return types of server-side and client-side @Request-annotated interfaces</h5>
090 * <p>
091 * <h5 class='section'>See Also:</h5><ul>
092 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrc.Request">@Request</a>
093 * </ul>
094 *
095 * <div class='warn'>
096 *    This annotation should not be combined with the {@link Content @Content} annotation or <c>RestRequest#getContent()</c> method
097 *    for <c>application/x-www-form-urlencoded POST</c> posts, since it will trigger the underlying servlet
098 *    API to parse the body content as key-value pairs resulting in empty content.
099 *    <br>The {@link Query @Query} annotation can be used to retrieve a URL parameter in the URL string without triggering the
100 *    servlet to drain the body content.
101 * </div>
102 * <div class='warn'>
103 *    If using this annotation on a Spring bean, note that you are likely to encounter issues when using on parameterized
104 *    types such as <code>List&lt;MyBean&gt;</code>.  This is due to the fact that Spring uses CGLIB to recompile classes
105 *    at runtime, and CGLIB was written before generics were introduced into Java and is a virtually-unsupported library.
106 *    Therefore, parameterized types will often be stripped from class definitions and replaced with unparameterized types
107 * (e.g. <code>List</code>).  Under these circumstances, you are likely to get <code>ClassCastExceptions</code>
108 * when trying to access generalized <code>JsonMaps</code> as beans.  The best solution to this issue is to either
109 * specify the parameter as a bean array (e.g. <code>MyBean[]</code>) or declare the method as final so that CGLIB
110 * will not try to recompile it.
111 * </div>
112 *
113 * <h5 class='section'>See Also:</h5><ul>
114
115 * </ul>
116 */
117@Documented
118@Target({PARAMETER,METHOD,TYPE,FIELD})
119@Retention(RUNTIME)
120@Inherited
121@Repeatable(FormDataAnnotation.Array.class)
122@ContextApply(FormDataAnnotation.Applier.class)
123public @interface FormData {
124
125   /**
126    * Default value for this parameter.
127    *
128    * @return The annotation value.
129    */
130   String def() default "";
131
132   /**
133    * FORM parameter name.
134    *
135    * <p>
136    * The name of the parameter (required).
137    *
138    * <p>
139    * The value should be either a valid form parameter name, or <js>"*"</js> to represent multiple name/value pairs
140    *
141    * <p>
142    * A blank value (the default) has the following behavior:
143    * <ul class='spaced-list'>
144    *    <li>
145    *       If the data type is <c>NameValuePairs</c>, <c>Map</c>, or a bean,
146    *       then it's the equivalent to <js>"*"</js> which will cause the value to be serialized as name/value pairs.
147    *
148    *       <h5 class='figure'>Examples:</h5>
149    *       <p class='bjava'>
150    *    <jc>// When used on a REST method</jc>
151    *    <ja>@RestPost</ja>(<js>"/addPet"</js>)
152    *    <jk>public void</jk> addPet(<ja>@FormData</ja> JsonMap <jv>allFormDataParameters</jv>) {...}
153    *       </p>
154    *       <p class='bjava'>
155    *    <jc>// When used on a remote method parameter</jc>
156    *    <ja>@RemoteResource</ja>(path=<js>"/myproxy"</js>)
157    *    <jk>public interface</jk> MyProxy {
158    *
159    *       <jc>// Equivalent to @FormData("*")</jc>
160    *       <ja>@RemotePost</ja>(<js>"/mymethod"</js>)
161    *       String myProxyMethod1(<ja>@FormData</ja> Map&lt;String,Object&gt; <jv>allFormDataParameters</jv>);
162    *    }
163    *       </p>
164    *       <p class='bjava'>
165    *    <jc>// When used on a request bean method</jc>
166    *    <jk>public interface</jk> MyRequest {
167    *
168    *       <jc>// Equivalent to @FormData("*")</jc>
169    *       <ja>@FormData</ja>
170    *       Map&lt;String,Object&gt; getFoo();
171    *    }
172    *       </p>
173    *    </li>
174    *    <li>
175    *       If used on a request bean method, uses the bean property name.
176    *
177    *       <h5 class='figure'>Example:</h5>
178    *       <p class='bjava'>
179    *    <jk>public interface</jk> MyRequest {
180    *
181    *       <jc>// Equivalent to @FormData("foo")</jc>
182    *       <ja>@FormData</ja>
183    *       String getFoo();
184    *    }
185    *       </p>
186    *    </li>
187    * </ul>
188    *
189    * <h5 class='section'>Notes:</h5><ul>
190    *    <li class='note'>
191    *       The format is plain-text.
192    * </ul>
193    *
194    * @return The annotation value.
195    */
196   String name() default "";
197
198   /**
199    * Dynamically apply this annotation to the specified classes.
200    *
201    * <h5 class='section'>See Also:</h5><ul>
202    *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
203    * </ul>
204    *
205    * @return The annotation value.
206    */
207   String[] on() default {};
208
209   /**
210    * Dynamically apply this annotation to the specified classes.
211    *
212    * <p>
213    * Identical to {@link #on()} except allows you to specify class objects instead of a strings.
214    *
215    * <h5 class='section'>See Also:</h5><ul>
216    *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
217    * </ul>
218    *
219    * @return The annotation value.
220    */
221   Class<?>[] onClass() default {};
222
223   /**
224    * Specifies the {@link HttpPartParser} class used for parsing strings to values.
225    *
226    * <p>
227    * Overrides for this part the part parser defined on the REST resource which by default is {@link OpenApiParser}.
228    *
229    * @return The annotation value.
230    */
231   Class<? extends HttpPartParser> parser() default HttpPartParser.Void.class;
232
233   /**
234    * <mk>schema</mk> field of the <a class='doclink' href='https://swagger.io/specification/v2#parameterObject'>Swagger Parameter Object</a>.
235    *
236    * <p>
237    * The schema defining the type used for parameter.
238    *
239    * <p>
240    * The {@link Schema @Schema} annotation can also be used standalone on the parameter or type.
241    * Values specified on this field override values specified on the type, and values specified on child types override values
242    * specified on parent types.
243    *
244    * <h5 class='section'>Used for:</h5>
245    * <ul class='spaced-list'>
246    *    <li>
247    *       Server-side schema-based parsing and parsing validation.
248    *    <li>
249    *       Server-side generated Swagger documentation.
250    *    <li>
251    *       Client-side schema-based serializing and serializing validation.
252    * </ul>
253    *
254    * @return The annotation value.
255    */
256   Schema schema() default @Schema;
257
258   /**
259    * Specifies the {@link HttpPartSerializer} class used for serializing values to strings.
260    *
261    * <p>
262    * Overrides for this part the part serializer defined on the REST client which by default is {@link OpenApiSerializer}.
263    *
264    * @return The annotation value.
265    */
266   Class<? extends HttpPartSerializer> serializer() default HttpPartSerializer.Void.class;
267
268   /**
269    * A synonym for {@link #name()}.
270    *
271    * <p>
272    * Allows you to use shortened notation if you're only specifying the name.
273    *
274    * <p>
275    * The following are completely equivalent ways of defining a form post entry:
276    * <p class='bjava'>
277    *    <jk>public</jk> Order placeOrder(<ja>@FormData</ja>(name=<js>"petId"</js>) <jk>long</jk> <jv>petId</jv>) {...}
278    * </p>
279    * <p class='bjava'>
280    *    <jk>public</jk> Order placeOrder(<ja>@FormData</ja>(<js>"petId"</js>) <jk>long</jk> <jv>petId</jv>) {...}
281    * </p>
282    *
283    * @return The annotation value.
284    */
285   String value() default "";
286}