Java springboot之拦截器

• 拦截器  LoginHandlerInterceptor.java

package com.example.demo1.component;

import org.springframework.web.servlet.HandlerInterceptor;

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


public class LoginHandlerInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object loginSession = request.getSession().getAttribute("user");
        if (loginSession == null) {
            // 未登录
            request.setAttribute("msg", "未登录被拦截");
            // 重定向get请求到登录页面
            request.getRequestDispatcher("/user/login").forward(request, response);
            return false;
        } else {
            // 已登录
            return true;
        }
    }
}

• 注册拦截器

package com.example.demo1.config;

import com.example.demo1.component.LoginHandlerInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;


@Configuration
public class LoginConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 注册TestInterceptor拦截器
        InterceptorRegistration registration = registry.addInterceptor(new LoginHandlerInterceptor());
        // 所有路径都被拦截
        registration.addPathPatterns("/**");
        // 添加不拦截路径
        registration.excludePathPatterns("/user/login");
    }
}