Springboot项目使用拦截器方法详解

冷不防 2022-12-05 02:20 89阅读 0赞

#### 1. 创建一个拦截器并实现HandlerInterceptor接口 ####

package com.leiyuan.bs.interceptor;
    
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    // 拦截器
    public class MyHandlerInterceptor implements HandlerInterceptor {
      /**
       * 拦截（Controller方法调用之前）
       *
       * @param request request
       * @param response response
       * @param o    o
       * @return 通过与否
       * @throws Exception 异常处理
       */
      @Override
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object
          o) throws Exception {
        // TODO 我这里是通过用户是否登陆进行拦截，我的用户信息存储在session中，名称为userSession，大家可以自行实现
        if (request.getSession().getAttribute("userSession") == null) {
          // 拦截至登陆页面
          request.getRequestDispatcher("/user/toLogin").forward(request, response);
          // false为不通过
          return false;
        }
        // true为通过
        return true;
      }
    
      // 此方法为处理请求之后调用（调用过controller方法之后，跳转视图之前）
      @Override
      public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o,
                  ModelAndView modelAndView) throws Exception {
    
      }
    
      // 此方法为整个请求结束之后进行调用
      @Override
      public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,
                    Object o, Exception e) throws Exception {
    
      }
    }

##### 2. 创建一个配置类MyHandlerInterceptorConfig并继承WebMvcConfigurerAdapter类重写addInterceptors(InterceptorRegistry registry)方法 #####

package com.leiyuan.bs;
    
    import com.leiyuan.bs.interceptor.MyHandlerInterceptor;
    import org.springframework.stereotype.Component;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
    // 拦截器配置类
    @Component
    public class MyHandlerInterceptorConfig extends WebMvcConfigurerAdapter {
      @Override
      public void addInterceptors(InterceptorRegistry registry) {
      	/**
         * 这里的addPathPatterns("/**")为配置需要拦截的方法“/**”代表所有，而后excludePathPatterns("/user/toLogin")等方法为排除哪些方法不进行		 拦截
         */
        registry.addInterceptor(new MyHandlerInterceptor()).addPathPatterns("/**").excludePathPatterns("/user/toLogin").excludePathPatterns
            ("/user/login").excludePathPatterns("/user/toNewUser").excludePathPatterns("/user/newUser");
        super.addInterceptors(registry);
      }
    }

#### 3. 启动项目即可看到效果了 ####