Interceptor(拦截器)

1. Interceptor类

package cn.wolfcode.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

public class DemoInterceptor implements HandlerInterceptor {
    //前置拦截器
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //在访问控制器之前拦截
        System.out.println("在访问控制器之前拦截");
        return true;
    }
    //试图解析器
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        //试图解析完拦截
    }
    //后置拦截器
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        //访问完控制器之后拦截
        System.out.println("访问完控制器之后拦截");

    }
}

1. SpringBoot配置

package cn.wolfcode;

import cn.wolfcode.filterdemo.FilterDemo;
import cn.wolfcode.interceptor.DemoInterceptor;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@SpringBootApplication
public class AppStart implements WebMvcConfigurer {
    /**
     * 配置过滤器
     * @return
     */
    @Bean
    public FilterDemo filterDemo(){
        return new FilterDemo();
    }

    /**
     * 配置拦截器
     * 配置类实现 WebMvcConfigurer接口
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //注册TestInterceptor拦截器
        InterceptorRegistration registration = registry.addInterceptor(new DemoInterceptor());
        registration.addPathPatterns("/**");                      //所有路径都被拦截
        registration.excludePathPatterns(                         //添加不拦截路径

        );
    }


    public static void main(String[] args) {
        SpringApplication.run(AppStart.class,args);
    }
}