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<String, String>} 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}