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Spring Boot Web上下文工具类详解：获取Request、Response和参数

news 2025/11/5 8:00:14

Spring Boot Web上下文工具类详解：获取Request、Response和参数

工具类概述

这个CommonServletUtil工具类提供了在Spring Boot应用中便捷地获取Web上下文相关对象的方法，包括HttpServletRequest、HttpServletResponse以及从多种来源获取参数值。

功能特点

多来源参数获取：从请求参数、请求头、Cookie和属性中获取值
Web上下文检测：判断当前是否处于Web环境中
异常处理：对非Web上下文情况进行友好错误提示
便捷访问：静态方法直接调用，无需注入

完整代码

package com.mnsn.framework.boot.utils;import cn.hutool.core.util.ObjectUtil;
import com.mnsn.framework.commons.exception.CheckedException;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.Generated;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;/*** Servlet工具类* 提供Web上下文相关操作的工具方法* * @author mnsn* @version 1.0* @date 2024-01-15*/
public class CommonServletUtil {@Generatedprivate static final Logger log = LoggerFactory.getLogger(CommonServletUtil.class);private CommonServletUtil() {// 工具类，防止实例化}/*** 从请求中获取参数值* 按照以下顺序查找：请求参数 -> 请求头 -> Cookie -> 请求属性** @param paramName 参数名* @return 参数值，如果未找到返回null*/public static String getParamFromRequest(String paramName) {HttpServletRequest request = getRequest();String paramValue = request.getParameter(paramName);// 1. 从请求参数中获取if (ObjectUtil.isEmpty(paramValue)) {paramValue = request.getHeader(paramName);}// 2. 从请求头中获取if (ObjectUtil.isEmpty(paramValue)) {Cookie[] cookies = request.getCookies();if (ObjectUtil.isNotEmpty(cookies)) {// 3. 从Cookie中获取for (Cookie cookie : cookies) {String cookieName = cookie.getName();if (cookieName.equals(paramName)) {return cookie.getValue();}}}}// 4. 从请求属性中获取if (ObjectUtil.isEmpty(paramValue)) {paramValue = String.valueOf(request.getAttribute(paramName));}return paramValue;}/*** 获取当前请求的HttpServletRequest对象** @return HttpServletRequest对象* @throws CheckedException 非Web上下文时抛出异常*/public static HttpServletRequest getRequest() {ServletRequestAttributes servletRequestAttributes;try {servletRequestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();} catch (Exception var2) {log.error(">>> 非Web上下文无法获取Request：", var2);throw new CheckedException("非Web上下文无法获取Request");}if (servletRequestAttributes == null) {throw new CheckedException("非Web上下文无法获取Request");} else {return servletRequestAttributes.getRequest();}}/*** 获取当前请求的HttpServletResponse对象** @return HttpServletResponse对象* @throws CheckedException 非Web上下文时抛出异常*/public static HttpServletResponse getResponse() {ServletRequestAttributes servletRequestAttributes;try {servletRequestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();} catch (Exception var2) {log.error(">>> 非Web上下文无法获取Response：", var2);throw new CheckedException("非Web上下文无法获取Response");}if (servletRequestAttributes == null) {throw new CheckedException("非Web上下文无法获取Response");} else {return servletRequestAttributes.getResponse();}}/*** 判断当前是否处于Web上下文中** @return true-在Web上下文中, false-不在Web上下文中*/public static boolean isWeb() {return RequestContextHolder.getRequestAttributes() != null;}
}

Maven依赖配置

<?xml version="1.0" encoding="UTF-8"?>
<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><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>3.0.0</version><relativePath/></parent><groupId>com.mnsn.framework</groupId><artifactId>common-utils</artifactId><version>1.0.0</version><properties><maven.compiler.source>17</maven.compiler.source><maven.compiler.target>17</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><hutool.version>5.8.11</hutool.version></properties><dependencies><!-- Spring Boot Web --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!-- Hutool工具包 --><dependency><groupId>cn.hutool</groupId><artifactId>hutool-core</artifactId><version>${hutool.version}</version></dependency><!-- Lombok --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><!-- 测试 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><configuration><excludes><exclude><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></exclude></excludes></configuration></plugin></plugins></build>
</project>

使用示例

1. 在Controller中使用

@RestController
@RequestMapping("/api/user")
public class UserController {@GetMapping("/info")public ResponseEntity<UserInfo> getUserInfo() {// 获取请求参数String userId = CommonServletUtil.getParamFromRequest("userId");String token = CommonServletUtil.getParamFromRequest("token");// 获取Request对象HttpServletRequest request = CommonServletUtil.getRequest();String userAgent = request.getHeader("User-Agent");UserInfo userInfo = userService.getUserInfo(userId, token);return ResponseEntity.ok(userInfo);}@PostMapping("/update")public ResponseEntity<String> updateUser(@RequestBody User user) {// 获取Response对象设置CookieHttpServletResponse response = CommonServletUtil.getResponse();Cookie cookie = new Cookie("lastUpdate", String.valueOf(System.currentTimeMillis()));response.addCookie(cookie);userService.updateUser(user);return ResponseEntity.ok("更新成功");}
}

2. 在Service中使用

@Service
public class UserService {public UserInfo getUserInfo(String userId, String token) {// 检查是否在Web上下文中if (CommonServletUtil.isWeb()) {String clientIp = CommonServletUtil.getRequest().getRemoteAddr();log.info("客户端IP: {}", clientIp);}// 业务逻辑...return userInfo;}
}

3. 在拦截器中使用

@Component
public class AuthInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {// 使用工具类获取tokenString token = CommonServletUtil.getParamFromRequest("Authorization");if (StringUtils.isEmpty(token)) {throw new UnauthorizedException("未授权访问");}// 验证token逻辑...return true;}
}

方法详解

getParamFromRequest(String paramName)

这个方法按照以下优先级从请求中获取参数值：

请求参数：request.getParameter(paramName)
请求头：request.getHeader(paramName)
Cookie：遍历所有Cookie查找匹配的名称
请求属性：request.getAttribute(paramName)

getRequest() 和 getResponse()

这两个方法通过Spring的RequestContextHolder获取当前线程绑定的请求和响应对象，如果不在Web上下文中会抛出CheckedException。

isWeb()

用于判断当前是否处于Web环境中，在异步任务或定时任务中特别有用。

注意事项

线程安全性：工具类中的方法都是静态的且无状态，可以在多线程环境中安全使用
Web上下文：在非Web环境（如单元测试、定时任务）中调用getRequest()/getResponse()会抛出异常
性能考虑：频繁调用getRequest()可能影响性能，建议在需要时缓存引用
空值处理：getParamFromRequest()方法在找不到参数时返回null，调用方需要处理空值情况

单元测试

@SpringBootTest
class CommonServletUtilTest {@Testvoid testIsWebInWebContext() {assertTrue(CommonServletUtil.isWeb());}@Testvoid testGetRequest() {HttpServletRequest request = CommonServletUtil.getRequest();assertNotNull(request);}@Testvoid testGetParamFromRequest() {// 需要通过Mock HttpServletRequest来测试// 具体实现略...}
}