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<String, String>} 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}