springBoot 登录拦截器

1、首选创建一个继承HandlerInterceptor的拦截器

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
/**
 * 拦截器
 */
public class MyInterceptor implements HandlerInterceptor{
    //在请求处理之前进行调用（Controller方法调用之前
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        HttpSession session = httpServletRequest.getSession();
        String user = (String) session.getAttribute("user"); //获取登录的session信息
        if(user!=null){
            return true;
        }
        else{
httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login/index");  //未登录自动跳转界面
            return false;
        }
    }

    //请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

        System.out.println("postHandle被调用\n");
    }

    //在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("afterCompletion被调用\n");
    }
}

　　2、继承WebMvcConfigureAdapter类，覆盖其addInterceptors接口,注册自定义的拦截器：

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    /**
     * 注册拦截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
　　　　//addPathPattern后跟拦截地址，excludePathPatterns后跟排除拦截地址
　　　　registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**").excludePathPatterns("/login/index").excludePathPatterns("/login/login"); 
    } 
}

　　

这样我们就可以在用户请求到达controller层实现登录拦截了，所有用户请求都会被拦截，在prehandle方法进行登录判断，返回true则验证通过，否则失败