001/*
002 * Copyright 2002-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.bind.annotation;
018
019import java.lang.annotation.Documented;
020import java.lang.annotation.ElementType;
021import java.lang.annotation.Retention;
022import java.lang.annotation.RetentionPolicy;
023import java.lang.annotation.Target;
024
025import org.springframework.core.annotation.AliasFor;
026
027/**
028 * Annotation which indicates that a method parameter should be bound to a URI template
029 * variable. Supported for {@link RequestMapping} annotated handler methods in Servlet
030 * environments.
031 *
032 * <p>If the method parameter is {@link java.util.Map Map&lt;String, String&gt;}
033 * then the map is populated with all path variable names and values.
034 *
035 * @author Arjen Poutsma
036 * @author Juergen Hoeller
037 * @since 3.0
038 * @see RequestMapping
039 * @see org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
040 */
041@Target(ElementType.PARAMETER)
042@Retention(RetentionPolicy.RUNTIME)
043@Documented
044public @interface PathVariable {
045
046        /**
047         * Alias for {@link #name}.
048         */
049        @AliasFor("name")
050        String value() default "";
051
052        /**
053         * The name of the path variable to bind to.
054         * @since 4.3.3
055         */
056        @AliasFor("value")
057        String name() default "";
058
059        /**
060         * Whether the path variable is required.
061         * <p>Defaults to {@code true}, leading to an exception being thrown if the path
062         * variable is missing in the incoming request. Switch this to {@code false} if
063         * you prefer a {@code null} or Java 8 {@code java.util.Optional} in this case.
064         * e.g. on a {@code ModelAttribute} method which serves for different requests.
065         * @since 4.3.3
066         */
067        boolean required() default true;
068
069}