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.
030 *
031 * <p>If the method parameter is {@link java.util.Map Map&lt;String, String&gt;}
032 * then the map is populated with all path variable names and values.
033 *
034 * @author Arjen Poutsma
035 * @author Juergen Hoeller
036 * @since 3.0
037 * @see RequestMapping
038 * @see org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
039 */
040@Target(ElementType.PARAMETER)
041@Retention(RetentionPolicy.RUNTIME)
042@Documented
043public @interface PathVariable {
044
045        /**
046         * Alias for {@link #name}.
047         */
048        @AliasFor("name")
049        String value() default "";
050
051        /**
052         * The name of the path variable to bind to.
053         * @since 4.3.3
054         */
055        @AliasFor("value")
056        String name() default "";
057
058        /**
059         * Whether the path variable is required.
060         * <p>Defaults to {@code true}, leading to an exception being thrown if the path
061         * variable is missing in the incoming request. Switch this to {@code false} if
062         * you prefer a {@code null} or Java 8 {@code java.util.Optional} in this case.
063         * e.g. on a {@code ModelAttribute} method which serves for different requests.
064         * @since 4.3.3
065         */
066        boolean required() default true;
067
068}