Spring 注解面面通之 @CookieValue

本文主要是介绍Spring 注解面面通之 @CookieValue，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

@CookieValue用于将请求的Cookie数据映射到控制器处理方法的参数中。

注解解析

① value：

绑定的参数名称，参数值为String类型。

② name：

绑定的参数名称，参数值为String类型。name和value可以同时使用，但两者的值需一致，否则会出现错误。

attribute 'name' and its alias 'value' are present with values of [XXX] and [XXX], but only one is permitted

③ required：

Cookie中是否必须包含指定的值，默认值为true.

required为true时，如果Cookie中缺少指定的值，则会抛出异常.

required为false时，如果Cookie中缺少指定的值，则会返回null.

④ defaultValue：

用作绑定失败时的默认值，若Cookie中缺少指定的值，使用此值作为默认值.

设置defaultValue时，会将required隐式的设置为false.

注解示例

1) 建Controller，用来演示@CookieValue使用方法。

package com.arhorchin.securitit.webannotations;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;import com.arhorchin.securitit.extend.initializer.CustomerApplicationContextInitializer;/*** @author Securitit.* @note 演示@CookieValue使用方法.*/
@Controller
@RequestMapping("/WebAnnotations")
public class CookieValueController {/*** logger.*/private Logger logger = LoggerFactory.getLogger(CustomerApplicationContextInitializer.class);/*** 跳转页面.*/@RequestMapping(value = "/CookieValue.html",method = RequestMethod.GET)public ModelAndView cookieValueHtml(HttpServletRequest req, HttpServletResponse res, ModelMap modelMap)throws Exception {req.getSession(true);return new ModelAndView("webannotations/CookieValue", modelMap);}/*** 从Cookie中获取JSESSIONID.*/@ResponseBody@RequestMapping(value = "/CookieValue.do",method = RequestMethod.GET)public String CookieValue(@CookieValue(value = "JSESSIONID") String jsessionId) throws Exception {logger.info("Current JSESSIONID is " + jsessionId);return "Current JSESSIONID is " + jsessionId;}/*** 从Cookie中获取DEFSESSIONID，DEFSESSIONID在Cookie中不存在，*  由于required设置为true，此时会抛出异常.*/@ResponseBody@RequestMapping(value = "/CookieValueRequiredTrue.do",method = RequestMethod.GET)public String CookieValueRequiredTrue(@CookieValue(value = "DEFSESSIONID",required = true) String jsessionId) throws Exception {logger.info("Current DEFSESSIONID is " + jsessionId);return "Current DEFSESSIONID is " + jsessionId;}/*** 从Cookie中获取DEFSESSIONID，DEFSESSIONID在Cookie中不存在，*  由于required设置为false，此时返回null.*/@ResponseBody@RequestMapping(value = "/CookieValueRequiredFalse.do",method = RequestMethod.GET)public String CookieValueRequiredFalse(@CookieValue(value = "DEFSESSIONID",required = false) String jsessionId) throws Exception {logger.info("Current DEFSESSIONID is " + jsessionId);return "Current DEFSESSIONID is " + jsessionId;}/*** 从Cookie中获取DEFSESSIONID，DEFSESSIONID在Cookie中不存在，*  由于设置了defaultValue，required隐式的设置为false，则返回默认值.*/@ResponseBody@RequestMapping(value = "/CookieValueDefault.do",method = RequestMethod.GET)public String cookieValueDefaultRequiredTest(@CookieValue(value = "DEFSESSIONID",defaultValue = "Securitit's CookieValue Test.") String jsessionId) throws Exception {logger.info("Current DEFSESSIONID is " + jsessionId);return "Current DEFSESSIONID is " + jsessionId;}}

2) 建html，用来演示CookieValueController示例。

<!doctype html>
<html lang="en"><head><meta charset="UTF-8"><meta name="Generator" content="EditPlus®"><meta name="Author" content=""><meta name="Keywords" content=""><meta name="Description" content=""><title>@CookieValue 测试页面</title></head><body><a href="http://localhost:9199/spring-annotations/WebAnnotations/CookieValue.do" target="_blank">点击链接，获取Cookie中的JSESSIONID.</a><br /><br /><a href="http://localhost:9199/spring-annotations/WebAnnotations/CookieValueRequiredTrue.do" target="_blank">点击链接，@CookieValue的required属性为true，抛出异常.</a><br /><br /><a href="http://localhost:9199/spring-annotations/WebAnnotations/CookieValueRequiredFalse.do" target="_blank">点击链接，@CookieValue的required属性为false，返回null.</a><br /><br /><a href="http://localhost:9199/spring-annotations/WebAnnotations/CookieValueDefault.do" target="_blank">点击链接，@CookieValue的defaultValue属性设置默认值，required隐式的设置为false.</a></body>
</html>