介绍
在项目中，如果需要在 Header 中获取请求头，一般使用 RequestHeader 注解。代码案例如下：
@RequestMapping("/normalHeaders") public Map<String, Object> normalHeaders(@RequestHeader("user-id")Long userId, @RequestHeader("tenant-id")Long tenantId, @RequestHeader("user-name")String userName){ Map<String, Object> map = new HashMap<>(); map.put("userId", userId); map.put("tenantId", tenantId); map.put("userName", userName); return map; }
请求curl
curl -X POST \ http://127.0.0.1:8080/normalHeaders \ -H 'tenant-id: 12' \ -H 'user-id: 1' \ -H 'user-name: buger'
使用 RequestHeader 注解获取请求头，如果获取一两个到不会写很多重复代码，但是如果需要获取很多个请求时，代码会变得重复。
下面介绍一种新的解决方案；不但减少了很多重复的代码，而且使得代码变得跟简洁。
pom.xml 文件引入依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.olive</groupId> <artifactId>springmvc-headers</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springmvc-headers</name> <url>http://maven.apache.org</url> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.5.14</version> <relativePath /> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> </project>
解析请求头，并包装
实现 HandlerMethodArgumentResolver 类；解析请求头，包装成 HeadersWrapperDTO 类
package com.olive.config; import com.olive.dto.HeadersWrapperDTO; import org.springframework.core.MethodParameter; import org.springframework.util.StringUtils; 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; public class RequestHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver { @Override public boolean supportsParameter(MethodParameter parameter) { return parameter.getParameterType().isAssignableFrom(HeadersWrapperDTO.class); } @Override public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception { String userId = webRequest.getHeader("user-id"); String tenantId = webRequest.getHeader("tenant-id"); String userName = webRequest.getHeader("user-name"); HeadersWrapperDTO headersWrapperDTO = new HeadersWrapperDTO(); if(StringUtils.hasText(userId)){ headersWrapperDTO.setUserId(Long.parseLong(userId)); } if(StringUtils.hasText(tenantId)){ headersWrapperDTO.setTenantId(Long.parseLong(tenantId)); } headersWrapperDTO.setUserName(userName); return headersWrapperDTO; } }
HeadersWrapperDTO POJO类
package com.olive.dto; import lombok.Data; import java.io.Serializable; @Data public class HeadersWrapperDTO implements Serializable { private Long userId; private Long tenantId; private String userName; }
注册 RequestHandlerMethodArgumentResolver 到 Controller 参数解析器里，即添加自己的参数解析器
package com.olive.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.method.support.HandlerMethodArgumentResolver; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; import java.util.List; @Configuration public class MethodArgumentResolverConfig { @Bean public WebMvcConfigurer getWebMvcConfigurer() { return new WebMvcConfigurer() { @Override public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) { resolvers.add(new RequestHandlerMethodArgumentResolver()); } }; } }
测试
编码 Springboot 启动引导类
package com.olive; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class Application { public static void main(String[] args) { SpringApplication.run(Application.class); } }
编写测试 Controller
package com.olive.controller; import java.util.HashMap; import java.util.Map; import com.olive.dto.HeadersWrapperDTO; import org.springframework.web.bind.annotation.RequestHeader; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class TestController { @RequestMapping("/normalHeaders") public Map<String, Object> normalHeaders(@RequestHeader("user-id")Long userId, @RequestHeader("tenant-id")Long tenantId, @RequestHeader("user-name")String userName){ Map<String, Object> map = new HashMap<>(); map.put("userId", userId); map.put("tenantId", tenantId); map.put("userName", userName); return map; } @RequestMapping("/wrapperHeaders") public Map<String, Object> wrapperHeaders(HeadersWrapperDTO headers){ Map<String, Object> map = new HashMap<>(); map.put("userId", headers.getUserId()); map.put("tenantId", headers.getTenantId()); map.put("userName", headers.getUserName()); return map; } }
测试curl
curl -X POST \ http://127.0.0.1:8080/wrapperHeaders \ -H 'tenant-id: 12' \ -H 'user-id: 1' \ -H 'user-name: buger'
通过 RequestHandlerMethodArgumentResolver 可以对请求头进行解析并封装到 HeadersWrapperDTO 类中，这样减少了在 Controller 使用大量的 RequestHeader 注解获取请求头。
