Springboot中使用Interceptor(拦截器)

1.创建自定义的拦截器并实现HandlerInterceptor接口

package com.demo.common.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class MyInterceptor implements HandlerInterceptor{
    
    Logger logger = LoggerFactory.getLogger(MyInterceptor.class);
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        logger.info("preHandle :" +request.getContextPath());
        HttpSession session = request.getSession();
        if (session.getAttribute("user") != null)
            return true;
        // 跳转登录
        String url = request.getContextPath() + "/login";
        response.sendRedirect(url);
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
   
    }
}

2.创建一个java类继承WebMvcConfiguraeAdapter并重写addInterceptor方法（该类用来添加配置拦截器在该类中添加配置拦截器，以及配置过滤）

package com.demo.common.interceptor;

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

@Configuration
public class AddInterceptor extends WebMvcConfigurerAdapter{
    
    public void addInterceptors(InterceptorRegistry registry){
        registry.addInterceptor(new MyInterceptor())
        .addPathPatterns("/**")
        .excludePathPatterns("/login")
        .excludePathPatterns("/loginPost");
    }
}