/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.bind.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.core.annotation.AliasFor;

Annotation which indicates that a method parameter should be bound to a URI template variable. Supported for RequestMapping annotated handler methods. 
If the method parameter is Map<String, String> then the map is populated with all path variable names and values. 
Author:
Arjen Poutsma, Juergen Hoeller
See Also:
RequestMapping
RequestMappingHandlerAdapter
Since:
3.0/**
 * Annotation which indicates that a method parameter should be bound to a URI template
 * variable. Supported for {@link RequestMapping} annotated handler methods.
 *
 * <p>If the method parameter is {@link java.util.Map Map&lt;String, String&gt;}
 * then the map is populated with all path variable names and values.
 *
 * @author Arjen Poutsma
 * @author Juergen Hoeller
 * @since 3.0
 * @see RequestMapping
 * @see org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface PathVariable {

	
Alias for name. /**
	 * Alias for {@link #name}.
	 */
	@AliasFor("name")
	String value() default "";

	
The name of the path variable to bind to.
Since:
4.3.3/**
	 * The name of the path variable to bind to.
	 * @since 4.3.3
	 */
	@AliasFor("value")
	String name() default "";

	
Whether the path variable is required.
Defaults to true, leading to an exception being thrown if the path variable is missing in the incoming request. Switch this to false if you prefer a null or Java 8 java.util.Optional in this case. e.g. on a ModelAttribute method which serves for different requests. 
Since:
4.3.3/**
	 * Whether the path variable is required.
	 * <p>Defaults to {@code true}, leading to an exception being thrown if the path
	 * variable is missing in the incoming request. Switch this to {@code false} if
	 * you prefer a {@code null} or Java 8 {@code java.util.Optional} in this case.
	 * e.g. on a {@code ModelAttribute} method which serves for different requests.
	 * @since 4.3.3
	 */
	boolean required() default true;

}