Spring拦截器（Interceptor）的使用

一.注册拦截器，定义一个类实现HandlerInterceptor接口，重写里面的三个方法，具体代码实现如下：

package com.luoluo.interceptor;

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

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

/**
 * @BelongsProject: spring-demo01
 * @BelongsPackage: com.luoluo.interceptor
 * @Author: lijialuo
 * @CreateTime: 2023-11-19  14:34
 * @Description: TODO 拦截器Demo注册
 * @Version: 1.0
 */

@Component //交给IOC容器管理
public class DemoInterceptor implements HandlerInterceptor {
    @Override//目标资源方法运行前运行；返回true，放行；返回false，不放行
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...");
        return true;
    }

    @Override//目标资源方法运行后运行
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle...");
    }

    @Override//视图渲染完毕后，最后运行
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}
二.定义一个配置类，实现WebMvcConfigurer接口，用于配置拦截器信息；具体代码实现如下：

package com.luoluo.config;

import com.luoluo.interceptor.DemoInterceptor;
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.WebMvcConfigurer;

/**
 * @BelongsProject: spring-demo01
 * @BelongsPackage: com.luoluo.config
 * @Author: lijialuo
 * @CreateTime: 2023-11-19  14:59
 * @Description: TODO
 * @Version: 1.0
 */
@Configuration //配置类注解
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private DemoInterceptor demoInterceptor;
    //注册拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //调用registry里面的addInterceptor添加拦截器,addPathPatterns配置需要拦截的资源
        registry.addInterceptor(demoInterceptor).addPathPatterns("/**");
    }
}