SpringBoot拦截器实现登录拦截的示例代码

package com.qcby.interceptor;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
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 {
 
    @Autowired
    private HttpSession httpSession;
    //Controller逻辑执行之前
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle....");
        String uri = request.getRequestURI();
        System.out.println("当前路径"+uri);
 
        /**
         * HandlerMethod=>Controller中标注@RequestMapping的方法
         *  需要配置静态资源不拦截时，添加这块逻辑  => 前后端分离项目
         */
        if (!(handler instanceof HandlerMethod)) {
            return true;
        }
        if (httpSession.getAttribute("username") == null) {
            // 未登录跳转到登录界面
            throw  new RuntimeException("no login!");
        } else {
            return true;
        }
    }
 
    //Controller逻辑执行完毕但是视图解析器还未进行解析之前
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle....");
    }
 
    //Controller逻辑和视图解析器执行完毕
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("afterCompletion....");
    }
}

package com.qcby.config;
 
import com.qcby.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Bean;
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 WebMvcConfig implements WebMvcConfigurer {
 
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginInterceptor())
                .addPathPatterns("/**")
                // 那些路径不拦截
                .excludePathPatterns("/user/login","/error");
    }
 
    @Bean
    public LoginInterceptor loginInterceptor(){
        return new LoginInterceptor();
    }
}

@RestController
@RequestMapping("user")
public class UserController {
@Autowired
    private UserService userService;
    @Autowired
    private HttpSession session;
    @ApiOperation("用户登录接口")
    @RequestMapping(value="login",method = {RequestMethod.GET,RequestMethod.POST})
    public Map<String,Object>login(User user){
        Map<String,Object> map=new HashMap<>();
        map.put("code",0);
        if(StringUtils.isEmpty(user.getUsername())||StringUtils.isEmpty(user.getPassword())){
            map.put("msg","用户或密码为空！");
            return map;
        }
        QueryWrapper<User> queryWrapper=new QueryWrapper<>();
        queryWrapper.eq("username",user.getUsername())
                .eq("password",user.getPassword());
        User user1=userService.getOne(queryWrapper);
        if(user1!=null){
            map.put("cod",1);
            map.put("data",user1);
            session.setAttribute("username",user1.getUsername());
        }else {
            map.put("msg","用户名或密码错误!");
        }
        return map;
    }
}