SpingBoot 拦截器的实现（登录拦截简单实现）

Posted 2021-07-18 yuwenS.

SpringBoot拦截器的配置

拦截器

1. 拦截器是springmvc中的一种，需要实现HandlerInterceptor接口
2. 拦截器是拦截用户发起的请求，而后对请求进行做判断处理
3. 拦截器是全局的，可以对多个Controller做拦截，一个项目有0个或多个拦截器。它们在一起拦截用户的请求，拦截器长用在：用户登录处理、权限检查、记录日志

拦截器的具体实现

用户登录拦截的简单实现

1. 拦截器规则的配置MyInterceptor 去实现HandlerInterceptor 接口

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //编写拦截器规则
        //从session中获取用户信息
        User user = (User) request.getSession().getAttribute("user");
        if (user == null){
            response.sendRedirect(request.getContextPath()+"/user/toLogin"); //如果没有登录则跳转去登录
            return false;
        }else{
            return true;
        }
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("执行postHandle方法！！！");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("执行afterCompletion！！！");
    }
}

2. 注入拦截器规则和要拦截路径的配置类InterceptorConfig实现WebMvcConfigurer接口

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        String[] addPathPatterns = {"/user/**"}; //要拦截的路径
        String[] excludePathPatterns = {"/user/login","/user/toLogin","/user/viewOrdinary"}; //不拦截的路劲
        registry.addInterceptor(new MyInterceptor()) //将登入验证拦截注入
                .addPathPatterns(addPathPatterns) //添加拦截路径
                .excludePathPatterns(excludePathPatterns); //添加不拦截的路径
    }
}

3. User实现类

public class User {
    private Integer id;
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

4. UserController类

@RestController
@RequestMapping("/user")
public class UserController {
    //登录
    @RequestMapping("/login")
    public String login(HttpServletRequest request){
        User user = new User();
        user.setId(10001);
        user.setName("小夏");
        request.getSession().setAttribute("user",user);
        return "login success";
    }
    //查看内容 需登入才能查看
    @RequestMapping("/viewContent")
    public String viewContent(){
        return "This is Content";
    }
    //未登录时去发起要登录才能进行的请求跳转到这
    @RequestMapping("/toLogin")
    public String toLogin(){
        return "permission denied ！！！ please login in";
    }
    //查看普通内容 未登入也能查看
    @RequestMapping("/viewOrdinary")
    public String viewOrdinary(){
        return "This is normal content";
    }
}

简单测试

登录过后才能操作的请求

直接能操作的请求

登录请求

登录成功后再次查看viewContent

通过测试可看出简单登录拦截器已经实现