Springboot项目使用拦截器方法详解

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