标签：根据 bre createdb sch scope pos rod public cto
HandlerMethodArgumentResolver 是什么？
就是用于解析参数的一个接口，springMVC（4.1）会直接调用这个接口的方法，对参数进行一定的解析。比如会在
InvocableHandlerMethod.getMethodArgumentValues（）中调用，并解析方法参数。
具体如图：
然后就会根据这个resolver的规则进行参数的解析。
如何实现？
下面我们可以自定义一个resolver并实现：
具体实现：
1.@CurrentUser
@Target({ElementType.PARAMETER}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface CurrentUser { /** * 当前用户在request中的名字 * * @return */ String value() default "user"; }
2.CurrentUserMethodArgumentResolver
package com.spring.custom_anno; import org.springframework.core.MethodParameter; import org.springframework.stereotype.Component; import org.springframework.web.bind.support.WebDataBinderFactory; import org.springframework.web.context.request.NativeWebRequest; import org.springframework.web.method.support.HandlerMethodArgumentResolver; import org.springframework.web.method.support.ModelAndViewContainer; @Component public class CurrentUserMethodArgumentResolver implements HandlerMethodArgumentResolver { public CurrentUserMethodArgumentResolver() { } @Override public boolean supportsParameter(MethodParameter parameter) { if (parameter.getParameterType().isAssignableFrom(UserBean.class) && parameter.hasParameterAnnotation(CurrentUser.class)) { return true; } return false; } @Override public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception { CurrentUser currentUserAnnotation = parameter.getParameterAnnotation(CurrentUser.class); //从Session 获取用户 Object object = webRequest.getAttribute(currentUserAnnotation.value(), NativeWebRequest.SCOPE_SESSION); //从 accessToken获得用户信息 if (object == null) { String token = webRequest.getHeader("Authorization"); if (token == null) { token = webRequest.getParameter("accessToken"); } //为了测试先写死用户名 //TODO: 取真实用户 return new UserBean(1L,"admin"); } return object; } }
3.UserBean
import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; import java.io.Serializable; @Data @NoArgsConstructor @AllArgsConstructor public class UserBean implements Serializable { private Long id; private String username; }
4.Controller
import org.springframework.web.bind.annotation.*; @RestController public class TestController { @RequestMapping(value = "/testCurrentUser", method = RequestMethod.POST, produces = "application/json", consumes = "application/json") public void test(@CurrentUser UserBean userBean) { String createdBy = userBean.getUsername(); System.out.println(createdBy); } }
5.配置
1.（在XML中自定义传统项目做法，注意 自动扫描一定要放在resolver配置的下面才能生效。。实践过）
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 基本包扫描 --> <context:component-scan base-package="com.spring" /> <!-- 注册HandlerMapper、HandlerAdapter两个映射类,负责将请求映射到类和方法中 --> <mvc:annotation-driven> <mvc:argument-resolvers> <bean class="com.spring.custom_anno.CurrentUserMethodArgumentResolver"/> </mvc:argument-resolvers> </mvc:annotation-driven> <mvc:annotation-driven /> <!-- 访问静态资源,如js, css文件等 --> <mvc:default-servlet-handler /> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/views/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
2.（springboot）
只需要在CurrentUserMethodArgumentResolver 类上加上@Component就行了。
SpringMVC_HandlerMethodArgumentResolver 实践
标签：根据 bre createdb sch scope pos rod public cto
原文地址：https://www.cnblogs.com/chenscript/p/11651400.html
