使用 spring boot 攔截器只需要兩個類，一個攔截器類，一個攔截器註冊類，示例程式碼如下：

建立使用者登入校驗攔截器LoginInterceptor:

package com.example.demo.intercepter;

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

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

public class LoginInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {

        HttpSession session = request.getSession();
        //使用者已登入
        if
 
 (session.getAttribute("user") != null) {
            return true;
        } else {//使用者未登入，直接跳轉登入頁面
            response.sendRedirect("/login");
            return false;
        }

    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws
 
 Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

建立攔截器註冊類WebConfigurer:

package com.example.demo.intercepter;

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 WebConfigurer extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //新增自定義攔截器和攔截路徑，此處對所有請求進行攔截，除了登入介面和登入介面
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("/**")
                .excludePathPatterns("/login", "/user/login");
    }
}

說明：addPathPatterns方法用於新增攔截路徑，excludePathPatterns方法用於新增不需要攔截的路徑，兩個方法的引數都是不定長陣列，可以同時新增多個路徑。

其他使用到的業務相關類
使用者控制類UserController

package com.example.demo.controller;

import com.example.demo.model.User;
import com.example.demo.repository.BaseRepository;
import com.example.demo.repository.UserRepository;
import com.example.demo.util.Result;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @PostMapping("/login")
    @ResponseBody
    public Result login(HttpSession session, User user) {
        //模擬登入
        if ("admin".equals(user.getUserName()) && "123456".equals(user.getPassword())){
            session.setAttribute("user", user);
            return new Result(Result.SUCCESS, "登入成功！");
        }
        return new Result(Result.FAILED, "登入失敗，請核對使用者名稱密碼後重試！");
    }

    @PostMapping("/logout")
    public String logout(HttpSession session) {
        session.removeAttribute("user");
        return "/login";
    }
}

首頁跳轉類IndexController:

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.HashMap;
import java.util.Map;

@Controller
public class IndexController {

    @RequestMapping("/index")
    public String index(){
        return "index";
    }

    @RequestMapping("/login")
    public String login(){
        return "login";
    }
}