SpringMVC(七):@RequestHeader注解

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RequestHeader源码中方法和RequestParam相似，使用方式相似，针对请求头进行过滤 

/*
 * Copyright 2002-2014 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;

/**
 * Annotation which indicates that a method parameter should be bound to a web request header.
 * Supported for annotated handler methods in Servlet and Portlet environments.
 *
 * 
If the method parameter is {@link java.util.Map Map<String, String>} or
 * {@link org.springframework.util.MultiValueMap MultiValueMap<String, String>},
 * or {@link org.springframework.http.HttpHeaders HttpHeaders} then the map is
 * populated with all header names and values.
 *
 * @author Juergen Hoeller
 * @since 3.0
 * @see RequestMapping
 * @see RequestParam
 * @see CookieValue
 * @see org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
 * @see org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestHeader {

	/**
	 * The name of the request header to bind to.
	 */
	String value() default "";

	/**
	 * Whether the header is required.
	 * 
Default is {@code true}, leading to an exception thrown in case
	 * of the header missing in the request. Switch this to {@code false}
	 * if you prefer a {@code null} in case of the header missing.
	 * 
Alternatively, provide a {@link #defaultValue}, which implicitly sets
	 * this flag to {@code false}.
	 */
	boolean required() default true;

	/**
	 * The default value to use as a fallback. Supplying a default value implicitly
	 * sets {@link #required} to {@code false}.
	 */
	String defaultValue() default ValueConstants.DEFAULT_NONE;

}

 

package com.levelcoder.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 
 * 描述:@RequestHeader注解
 *
 * 作者：LevelCoder
 *
 * 邮箱：[email protected]
 *
 * 日期:2017年6月6日 上午11:17:48
 *
 * 版本:V1.0.0
 */

@Controller
public class RequestHeaderController {

	/**
	 * 请求头包含若干个属性,服务器可根据这些属性获取客户端的信息
	 * @return
	 */
	@RequestMapping(value="/requestHeader")
	public String requestHeader(@RequestHeader("User-Agent") String ua){
		System.out.println("User-Agent:"+ua);
		return null;
	}
	
}

 

测试页面index

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







	
@RequestHeader 注解
	
	value
	required
	defaultValue
	

测试结果

 

附录常用RequestHeader解说

参数	说明
Accept	浏览器可以接收的内容类型
Accept-Encoding	浏览器可以处理的编码方式
Accept-Language	浏览器接收的语言
Cache-Control	指示缓存系统应该怎样处理缓存
Connection	告诉服务器这个user agent想要使用怎样的连接方式
Host	被访服务器的域名或IP地址
If-Modified-Since	如果请求的部分在指定时间之后被修改则请求成功，未被修改则返回304代码
If-None-Match	与服务器回应的Etag比较判断是否改变
Referer	先前网页的地址，当前请求网页紧随其后,即来路
Upgrade-Insecure-Requests	请求服务器更新至另外一个协议
User-Agent	User-Agent的内容包含发出请求的用户信息

 

 

 

转载于:https://my.oschina.net/LevelCoder/blog/916278