Restful Api 的拦截

向右看齐 2022-03-20 06:58 182阅读 0赞

### 文章目录 ###

*  过滤器 Filter（javaee提供）
 *   *  定义时间拦截器
     *  请求方法
     *  运行测试
     *  第三方拦截器的使用
 *  拦截器 Interceptor(spring 框架本身提供)
 *   *  自定义拦截器
     *  配置拦截器
     *  测试1
     *  测试2 服务抛出异常
     *  测试三 服务抛出运行时异常
 *  切片 Aspect
 *   *  aop介绍
     *  加入aop依赖
     *  自定义切片
     *  测试
 *  总结

# 过滤器 Filter（javaee提供） #

## 定义时间拦截器 ##

![在这里插入图片描述][20190211132924344.png]

/**
     * @Package com.whale.web.filter
     * @Description: 时间拦截器
     * @date 2019/2/11 13:18
     */
    @Component//使拦截器生效
    public class TimeFilter implements Filter {
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.println("TimeFilter init");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            System.out.println("TimeFilter start");
            long start = new Date().getTime();
            filterChain.doFilter(servletRequest,servletResponse);
            long end = new Date().getTime();
            System.out.println("TimeFilter耗时(毫秒) : " +(end-start));
            System.out.println("TimeFilter finish");
        }
    
        @Override
        public void destroy() {
            System.out.println("TimeFilter destroy");
        }
    }

## 请求方法 ##

/**
         * @param idxx
         * @return
         */
        @GetMapping("{id:\\d++}")
        @JsonView(User.UserSimpleView.class)
        public User getInfo4( @PathVariable(name = "id") String idxx){
            System.out.println("=================");
    
            //throw new UserNotExistException(idxx);
            //System.out.println(idxx);
            System.out.println("进入getInfo服务");
            User u = new User();
            u.setUsername("tom");
            return u;
        }

## 运行测试 ##

拦截器在运行的时候就已经初始化

访问 [http://127.0.0.1:8080/user/1][http_127.0.0.1_8080_user_1]

控制台如下  
![在这里插入图片描述][2019021113315290.png]

## 第三方拦截器的使用 ##

以前我们使用拦截器时只需要在web.xml里面定义好  
在spring boot 中需要再拦截器上加@Component注解

那如何使用第三方注解呢(不能使用注解了)

*  注释掉TimeFilter的@Component注解  
    ![在这里插入图片描述][20190211165113591.png]
 *  创建配置类  
    ![在这里插入图片描述][20190211170015531.png]

@Configuration
    public class WebConfig implements Serializable {
        @Bean
        public FilterRegistrationBean timeFilter(){
            FilterRegistrationBean registrationBean = new FilterRegistrationBean();
    
            TimeFilter timeFilter = new TimeFilter();
            registrationBean.setFilter(timeFilter);
    
            //设置过滤路径
            List<String> urls = new ArrayList<>();
            urls.add("/*");
            registrationBean.setUrlPatterns(urls);
    
            return registrationBean;
    
        }
    }

*  测试ok

# 拦截器 Interceptor(spring 框架本身提供) #

## 自定义拦截器 ##

![在这里插入图片描述][20190211220029485.png]

@Component
    public class TimeInterceptor implements HandlerInterceptor {
    
        @Override
        public  boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
            System.out.println("preHandle");
            request.setAttribute("startTime",new Date().getTime());
            return true;
        }
    
        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,ModelAndView modelAndView) throws Exception {
            System.out.println("postHandle");
            Long startTime = (Long) request.getAttribute("startTime");
            System.out.println("time interceptor 耗时："+(new Date().getTime()-startTime));
        }
    
    
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,Exception ex) throws Exception {
            System.out.println("afterCompletion");
            Long startTime = (Long) request.getAttribute("startTime");
            System.out.println("time interceptor 耗时："+(new Date().getTime()-startTime));
            System.out.println("ex is" +ex);
        }
    }

## 配置拦截器 ##

![在这里插入图片描述][201902112213025.png]

@SuppressWarnings("deprecation")
    @Configuration
    public class WebConfig extends WebMvcConfigurerAdapter {
    
        @Autowired
        private TimeInterceptor timeInterceptor;
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            registry.addInterceptor(timeInterceptor);
        }
    }

## 测试1 ##

访问 [http://127.0.0.1:8080/user/1][http_127.0.0.1_8080_user_1]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70]

## 测试2 服务抛出异常 ##

/**
         * @param idxx
         * @return
         */
        @GetMapping("{id:\\d++}")
        @JsonView(User.UserSimpleView.class)
        public User getInfo4( @PathVariable(name = "id") String idxx){
            System.out.println("=================");
    
            throw new UserNotExistException(idxx);
            //System.out.println(idxx);
            //System.out.println("进入getInfo服务");
            //User u = new User();
            //u.setUsername("tom");
            //return u;
        }

500错误

{"messsage":"user not exists ! ","id":"1"}

控制台  
![在这里插入图片描述][2019021122202680.png]  
这次没有打印出postHandle，ex 仍然为空

这是因为异常UserNotExistException被 controller异常处理器吞掉了  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 1]

## 测试三 服务抛出运行时异常 ##

/**
         * @param idxx
         * @return
         */
        @GetMapping("{id:\\d++}")
        @JsonView(User.UserSimpleView.class)
        public User getInfo4( @PathVariable(name = "id") String idxx){
            System.out.println("=================");
    
            //throw new UserNotExistException(idxx);
            throw  new RuntimeException("user is not exists");
            //System.out.println(idxx);
            //System.out.println("进入getInfo服务");
            //User u = new User();
            //u.setUsername("tom");
            //return u;
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 2]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 3]

拦截器会拦截所有控制器

# 切片 Aspect #

拦截器不能拿到拦截方法参数中的值

如果需要知道拦截方法中的参数，就需要切片

## aop介绍 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 4]

## 加入aop依赖 ##

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
                
            </dependency>

## 自定义切片 ##

![在这里插入图片描述][20190212000437527.png]

@Aspect
    @Component
    public class TimeAspect{
    
        //@Before() 相当于 拦截器的 preHandle
        //@After()
        //@AfterThrowing 抛出异常时调用
    
        //@Around()      切入点 覆盖了上面三种 我们一般用这个
    
        //第一个*  可以是任何返回值
        //第二个*  类中的任何一个方法
        //(..)    方法中的任意参数
    
        //参考aop表达式语法
        // https://docs.spring.io/spring/docs/4.3.22.RELEASE/spring-framework-reference/htmlsingle/#aop-pointcuts-examples
        @Around("execution(* com.whale.web.controller.UserController.*(..))")
        public Object handleControllerMethod(ProceedingJoinPoint pjp) throws Throwable {
            System.out.println("time aspect start ");
    
            Object[] args = pjp.getArgs();
            for (Object arg : args) {
                System.out.println("arg is " + arg);
            }
            long start = new Date().getTime();
    
            Object object = pjp.proceed(); //切入点方法的返回值
    
            System.out.println("time aspect 耗时： "+ (new Date().getTime()-start));
    
            System.out.println("time aspect end ");
    
    
            return object;
        }
    }

## 测试 ##

/**
         * @param idxx
         * @return
         */
        @GetMapping("{id:\\d++}")
        @JsonView(User.UserSimpleView.class)
        public User getInfo4( @PathVariable(name = "id") String idxx){
            System.out.println("=================");
    
            //throw new UserNotExistException(idxx);
            //throw  new RuntimeException("user is not exists");
            System.out.println(idxx);
            System.out.println("进入getInfo服务");
            User u = new User();
            u.setUsername("tom");
            return u;
        }

访问 [http://127.0.0.1:8080/user/1][http_127.0.0.1_8080_user_1]  
控制台如下  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 5]

# 总结 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 6]

[20190211132924344.png]: /images/20220320/5ef4df3965db4315852bf3acae1d8dc0.png
[http_127.0.0.1_8080_user_1]: http://127.0.0.1:8080/user/1
[2019021113315290.png]: /images/20220320/4cd96243e74f4fae90a1c77523c74f6a.png
[20190211165113591.png]: /images/20220320/1811b2f786884a4496f8762c90f6ba19.png
[20190211170015531.png]: /images/20220320/0df5498cb6c14b6fbca90f8faba2b5bb.png
[20190211220029485.png]: /images/20220320/163672c270e24fdc9c5b2fa8b9577b4c.png
[201902112213025.png]: /images/20220320/c89cfd76cf9d4670b31833b033873280.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70]: /images/20220320/fdfbd42482f94023967808b8a231c43b.png
[2019021122202680.png]: /images/20220320/f102ad0582f4472a93252bd1f268c114.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 1]: /images/20220320/4e947e47419e4fa4ae819063ba5beba2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 2]: /images/20220320/60f9a3387bd84c7592053fa006222579.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 3]: /images/20220320/e410bacd466c43c2879f2fa840f8a856.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 4]: /images/20220320/5f519aa77817481bb6181e712d99e99d.png
[20190212000437527.png]: /images/20220320/9387c712868b4badbda3970662c445a6.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 5]: /images/20220320/a1a1c4f42df249f8874f3c34d8263f42.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3VvdGFpbA_size_16_color_FFFFFF_t_70 6]: /images/20220320/00efe3d25ef24d3db88c8aaff06c3c0c.png