Spring boot拦截器的实现

Spring boot自带HandlerInterceptor，可通过继承它来实现拦截功能，其的功能跟过滤器类似，但是提供更精细的的控制能力。

1.注册拦截器

 @Configuration
 public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
     @Bean   //把我们的拦截器注入为bean
     public HandlerInterceptor getMyInterceptor(){
         return new Interceptor();
     }     @Override
     public void addInterceptors(InterceptorRegistry registry) {
         // addPathPatterns 用于添加拦截规则, 这里假设拦截 /url 后面的全部链接
         // excludePathPatterns 用户排除拦截
         registry.addInterceptor(getMyInterceptor()).addPathPatterns("/**");
         super.addInterceptors(registry);
     }
 }

2.创建拦截器，写要过滤的请求等

 public class Interceptor implements HandlerInterceptor {     private Logger logger = LoggerFactory.getLogger(URLInterceptor.class);     public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
             throws Exception {
         // TODO Auto-generated method stub     }     public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
             throws Exception {
         // TODO Auto-generated method stub     }     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
         String flag = null;
         flag = request.getParameter("auth");
         if(StringUtils.isEmpty(flag) || !flag.equals("php")){
             logger.error("error-auth:{}", flag);
             return false;
         } else {
             logger.info("通过校验！");
             return true;
         }
     }
 }

3.取消拦截

上面是拦截所有接口，如果想某个接口取消拦截，怎么办？

新建一个类

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface UnAuthority {}

4.在不需要拦截的方法上面添加新增的注解,如下

@UnAuthority
@RequestMapping("/hello")
    public String hello(){
        return "Hello World";
    }

5.修改拦截器的preHandle方法,如下

public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {        // 检测请求的方法是否有UnAuthority注解，有注解不拦截，直接放行，返回true。
        HandlerMethod handlerMethod = (HandlerMethod)arg2;
        Method method = handlerMethod.getMethod();
        UnAuthority unAuthority = method.getAnnotation(UnAuthority.class);
        if(unAuthority != null ){
            return true;
        }         String flag = null;
         flag = request.getParameter("auth");
         if(StringUtils.isEmpty(flag) || !flag.equals("php")){
             logger.error("error-auth:{}", flag);
             return false;
         } else {
             logger.info("通过校验！");
             return true;
         }
     }

6.不需要auth参数访问/hello接口，成功。

新增了无需拦截的注解后,就可以根据业务需求哪些是需要拦截,哪些是不需要拦截

参考：https://blog.csdn.net/wsbgmofo/article/details/79151947