SpringBoot之HandlerInterceptor拦截器的使用详解

前言

平常项目开发过程中，会遇到登录拦截，权限校验，参数处理，防重复提交等问题，那拦截器就能帮我们统一处理这些问题。

一、实现方式

1.1 自定义拦截器

自定义拦截器，即拦截器的实现类，一般有两种自定义方式：

定义一个类，实现org.springframework.web.servlet.HandlerInterceptor接口。

定义一个类，继承已实现了HandlerInterceptor接口的类，例如org.springframework.web.servlet.handler.HandlerInterceptorAdapter抽象类。

1.2 添加Interceptor拦截器到WebMvcConfigurer配置器中

自定义配置器，然后实现WebMvcConfigurer配置器。

以前一般继承org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter类，不过SrpingBoot 2.0以上WebMvcConfigurerAdapter类就过时了。有以下2中替代方法：

直接实现org.springframework.web.servlet.config.annotation.WebMvcConfigurer接口。（推荐）

继承org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport类。但是继承WebMvcConfigurationSupport会让SpringBoot对mvc的自动配置失效。不过目前大多数项目是前后端分离，并没有对静态资源有自动配置的需求，所以继承WebMvcConfigurationSupport也未尝不可。

二、HandlerInterceptor 方法介绍

preHandle：预处理，在业务处理器处理请求之前被调用，可以进行登录拦截，编码处理、安全控制、权限校验等处理；

default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {return true;}

postHandle：后处理，在业务处理器处理请求执行完成后，生成视图之前被调用。即调用了Service并返回ModelAndView，但未进行页面渲染，可以修改ModelAndView，这个比较少用。

default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,@Nullable ModelAndView modelAndView) throws Exception {}

afterCompletion：返回处理，在DispatcherServlet完全处理完请求后被调用，可用于清理资源等。已经渲染了页面。

default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,@Nullable Exception ex) throws Exception {}

三、拦截器（Interceptor）实现

3.1 实现HandlerInterceptor

此拦截器演示了通过注解形式，对用户权限进行拦截校验。

package com.nobody.interceptor;import com.nobody.annotation.UserAuthenticate;import com.nobody.context.UserContext;import com.nobody.context.UserContextManager;import com.nobody.exception.RestAPIError;import com.nobody.exception.RestException;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import org.springframework.web.method.HandlerMethod;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * @Description * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Slf4j@Componentpublic class UserPermissionInterceptor implements HandlerInterceptor { private UserContextManager userContextManager; @Autowired public void setContextManager(UserContextManager userContextManager) { this.userContextManager = userContextManager; } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) { log.info('>>> UserPermissionInterceptor preHandle -- '); if (handler instanceof HandlerMethod) { HandlerMethod handlerMethod = (HandlerMethod) handler; // 获取用户权限校验注解(优先获取方法，无则再从类获取) UserAuthenticate userAuthenticate = handlerMethod.getMethod().getAnnotation(UserAuthenticate.class); if (null == userAuthenticate) {userAuthenticate = handlerMethod.getMethod().getDeclaringClass() .getAnnotation(UserAuthenticate.class); } if (userAuthenticate != null && userAuthenticate.permission()) {// 获取用户信息UserContext userContext = userContextManager.getUserContext(request);// 权限校验if (userAuthenticate.type() != userContext.getType()) { // 如若不抛出异常，也可返回false throw new RestException(RestAPIError.AUTH_ERROR);} } } return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) { log.info('>>> UserPermissionInterceptor postHandle -- '); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { log.info('>>> UserPermissionInterceptor afterCompletion -- '); }}

3.2 继承HandlerInterceptorAdapter

package com.nobody.interceptor;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.stereotype.Component;import lombok.extern.slf4j.Slf4j;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;/** * @Description * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Slf4j@Componentpublic class UserPermissionInterceptorAdapter extends HandlerInterceptorAdapter { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) { log.info('>>> UserPermissionInterceptorAdapter preHandle -- '); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) { log.info('>>> UserPermissionInterceptorAdapter postHandle -- '); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { log.info('>>> UserPermissionInterceptorAdapter afterCompletion -- '); }}

四、配置器（WebMvcConfigurer）实现

4.1 实现WebMvcConfigurer（推荐）

package com.nobody.config;import com.nobody.context.UserContextResolver;import com.nobody.interceptor.UserPermissionInterceptor;import com.nobody.interceptor.UserPermissionInterceptorAdapter;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.web.method.support.HandlerMethodArgumentResolver;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;import java.util.List;/** * @Description * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Configurationpublic class WebAppConfigurer implements WebMvcConfigurer { private UserPermissionInterceptor userPermissionInterceptor; private UserPermissionInterceptorAdapter userPermissionInterceptorAdapter; private UserContextResolver userContextResolver; @Autowired public void setUserPermissionInterceptor(UserPermissionInterceptor userPermissionInterceptor) { this.userPermissionInterceptor = userPermissionInterceptor; } @Autowired public void setUserPermissionInterceptorAdapter( UserPermissionInterceptorAdapter userPermissionInterceptorAdapter) { this.userPermissionInterceptorAdapter = userPermissionInterceptorAdapter; } @Autowired public void setUserContextResolver(UserContextResolver userContextResolver) { this.userContextResolver = userContextResolver; } @Override public void addInterceptors(InterceptorRegistry registry) { // 可以添加多个拦截器，一般只添加一个 // addPathPatterns('/**') 表示对所有请求都拦截 // .excludePathPatterns('/base/index') 表示排除对/base/index请求的拦截 // 多个拦截器可以设置order顺序，值越小，preHandle越先执行，postHandle和afterCompletion越后执行 // order默认的值是0，如果只添加一个拦截器，可以不显示设置order的值 registry.addInterceptor(userPermissionInterceptor).addPathPatterns('/**').excludePathPatterns('/base/index').order(0); // registry.addInterceptor(userPermissionInterceptorAdapter).addPathPatterns('/**') // .excludePathPatterns('/base/index').order(1); } @Override public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) { resolvers.add(userContextResolver); }}

4.2 继承WebMvcConfigurationSupport

package com.nobody.config;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;import com.nobody.interceptor.UserPermissionInterceptor;import com.nobody.interceptor.UserPermissionInterceptorAdapter;/** * @Description * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Configurationpublic class WebAppConfigurerSupport extends WebMvcConfigurationSupport { @Autowired private UserPermissionInterceptor userPermissionInterceptor; // @Autowired // private UserPermissionInterceptorAdapter userPermissionInterceptorAdapter; @Override public void addInterceptors(InterceptorRegistry registry) { // 可以添加多个拦截器，一般只添加一个 // addPathPatterns('/**') 表示对所有请求都拦截 // .excludePathPatterns('/base/index') 表示排除对/base/index请求的拦截 registry.addInterceptor(userPermissionInterceptor).addPathPatterns('/**').excludePathPatterns('/base/index'); // registry.addInterceptor(userPermissionInterceptorAdapter).addPathPatterns('/**') // .excludePathPatterns('/base/index'); }}

五、其他主要辅助类

5.1 用户上下文类

package com.nobody.context;import com.nobody.enums.AuthenticationTypeEnum;import lombok.Getter;import lombok.Setter;import lombok.ToString;/** * @Description 用户上下文 * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Getter@Setter@ToStringpublic class UserContext { // 用户名称 private String name; // 用户ID private String userId; // 用户类型 private AuthenticationTypeEnum type;}

5.2 校验访问权限注解

package com.nobody.context;import com.nobody.enums.AuthenticationTypeEnum;import lombok.Getter;import lombok.Setter;import lombok.ToString;/** * @Description 用户上下文 * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Getter@Setter@ToStringpublic class UserContext { // 用户名称 private String name; // 用户ID private String userId; // 用户类型 private AuthenticationTypeEnum type;}

5.3 用户上下文操作类

package com.nobody.context;import com.nobody.enums.AuthenticationTypeEnum;import com.nobody.exception.RestAPIError;import com.nobody.exception.RestException;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import org.springframework.util.StringUtils;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.util.Objects;import java.util.UUID;/** * @Description 用户上下文操作类 * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Componentpublic class UserContextManager { private static final String COOKIE_KEY = '__userToken'; // @Autowired // private RedisService redisService; /** * 获取用户上下文信息 * * @param request * @return */ public UserContext getUserContext(HttpServletRequest request) { String userToken = getUserToken(request, COOKIE_KEY); if (!StringUtils.isEmpty(userToken)) { // 从缓存或者第三方获取用户信息 // String userContextStr = redisService.getString(userToken); // if (!StringUtils.isEmpty(userContextStr)) { // return JSON.parseObject(userContextStr, UserContext.class); // } // 因为演示，没集成Redis，故简单new对象 UserContext userContext = new UserContext(); userContext.setName('Mr.nobody'); userContext.setUserId('0000001'); userContext.setType(AuthenticationTypeEnum.ADMIN); return userContext; } throw new RestException(RestAPIError.AUTH_ERROR); } public String getUserToken(HttpServletRequest request, String cookieKey) { Cookie[] cookies = request.getCookies(); if (null != cookies) { for (Cookie cookie : cookies) {if (Objects.equals(cookie.getName(), cookieKey)) { return cookie.getValue();} } } return null; } /** * 保存用户上下文信息 * * @param response * @param userContextStr */ public void saveUserContext(HttpServletResponse response, String userContextStr) { // 用户token实际根据自己业务进行生成，此处简单用UUID String userToken = UUID.randomUUID().toString(); // 设置cookie Cookie cookie = new Cookie(COOKIE_KEY, userToken); cookie.setPath('/'); response.addCookie(cookie); // redis缓存 // redisService.setString(userToken, userContextStr, 3600); }}

5.4 方法参数解析器类

package com.nobody.context;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;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;import javax.servlet.http.HttpServletRequest;/** * @Description 对有UserContext参数的接口，进行拦截注入用户信息 * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@Component@Slf4jpublic class UserContextResolver implements HandlerMethodArgumentResolver { @Autowired private UserContextManager userContextManager; @Override public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) { log.info('>>> resolveArgument -- begin...'); HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class); // 从缓存获取用户信息赋值到接口参数中 return userContextManager.getUserContext(request); } /** * 只对UserContext参数进行拦截赋值 * * @param methodParameter * @return */ @Override public boolean supportsParameter(MethodParameter methodParameter) { if (methodParameter.getParameterType().equals(UserContext.class)) { return true; } return false; }}

六、测试验证

package com.nobody.controller;import com.alibaba.fastjson.JSON;import com.nobody.annotation.UserAuthenticate;import com.nobody.context.UserContext;import com.nobody.context.UserContextManager;import com.nobody.enums.AuthenticationTypeEnum;import com.nobody.pojo.model.GeneralResult;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;/** * @Description * @Author Mr.nobody * @Date 2020/10/25 * @Version 1.0 */@RestController@RequestMapping('user')public class UserController { @Autowired private UserContextManager userContextManager; @GetMapping('login') public GeneralResult<UserContext> doLogin(HttpServletResponse response) { UserContext userContext = new UserContext(); userContext.setUserId('0000001'); userContext.setName('Mr.nobody'); userContext.setType(AuthenticationTypeEnum.ADMIN); userContextManager.saveUserContext(response, JSON.toJSONString(userContext)); return GeneralResult.genSuccessResult(userContext); } @GetMapping('personal') @UserAuthenticate(permission = true, type = AuthenticationTypeEnum.ADMIN) public GeneralResult<UserContext> getPersonInfo(UserContext userContext) { return GeneralResult.genSuccessResult(userContext); }}

启动服务后，在浏览器先调用personal接口，因为没有登录，所以会报错没有权限：

控制台输出：

启动服务后，在浏览器先访问login接口进行登录，再访问personal接口，验证通过，正确返回用户信息：

七、Github项目

项目工程可从Github获取，https://github.com/LucioChn/springboot-common.git

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