SpringBoot2 添加应用拦截器

项目参考：详细参见：《Spring Boot 2精髓：从构建小系统到架构分布式大系统》 第三章 3.6.1节 拦截器

MyWebMvcConfigurer

package com.archibladwitwicke.springboot2.chapter03.configurer;

import com.archibladwitwicke.springboot2.chapter03.intercept.AdminLoginIntercept;
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 MyWebMvcConfigurer implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 添加一个拦截器，连接以/admin为前缀的 url路径
        registry.addInterceptor(new AdminLoginIntercept()).addPathPatterns("/admin/**");
    }
}

　　

TestAdminController

package com.archibladwitwicke.springboot2.chapter03.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping("/admin")
public class TestAdminController {

    @RequestMapping("/hello")
    @ResponseBody
    public String say() {
        return "this is a admin page.";
    }
}

　　

AdminLoginIntecept

package com.archibladwitwicke.springboot2.chapter03.intercept;

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

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

public class AdminLoginIntercept implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 如果已经登录返回true。
        // 如果没有登录没有登录，可以使用 reponse.send() 跳转页面。后面要跟return false,否则无法结束;

        // 为了测试，打印一句话
        System.out.println("访问了admin下url路径。");

        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 {

    }
}