概述

使用场景：表单提交
作用： 防止用户在同一时刻连续点击提交，造成垃圾数据的生成
原理：根据url地址和上一次连接地址是否相同，如果相同，在10秒内不会重复提交

实现步骤

1、定义一个拦截器

/*** 防止重复提交拦截器** @author ruoyi*/
@Component
public abstract class RepeatSubmitInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {if (handler instanceof HandlerMethod) {HandlerMethod handlerMethod = (HandlerMethod) handler;Method method = handlerMethod.getMethod();RepeatSubmit annotation = method.getAnnotation(RepeatSubmit.class);if (annotation != null) {if (this.isRepeatSubmit(request, annotation)) {WebUtils.renderString(response, FastJsonUtil.toJSON(R.error(608, annotation.message())));return false;}}return true;} else {return true;}}/*** 验证是否重复提交由子类实现具体的防重复提交的规则** @param request    请求对象* @param annotation 防复注解* @return 结果*/public abstract boolean isRepeatSubmit(HttpServletRequest request, RepeatSubmit annotation) throws Exception;
}

2、实现者

/*** 判断请求url和数据是否和上一次相同，* 如果和上次相同，则是重复提交表单。 有效时间为10秒内。**/
@Component
public class SameUrlDataInterceptor extends RepeatSubmitInterceptor {public final String REPEAT_PARAMS = "repeatParams";public final String REPEAT_TIME = "repeatTime";public final String SESSION_REPEAT_KEY = "repeatData";@Overridepublic boolean isRepeatSubmit(HttpServletRequest request, RepeatSubmit annotation) throws Exception {// 本次参数及系统时间String nowParams = FastJsonUtil.toJSON(request.getParameterMap());Map<String, Object> nowDataMap = new HashMap<String, Object>();nowDataMap.put(REPEAT_PARAMS, nowParams);nowDataMap.put(REPEAT_TIME, System.currentTimeMillis());// 请求地址（作为存放session的key值）String url = request.getRequestURI();HttpSession session = request.getSession();Object sessionObj = session.getAttribute(SESSION_REPEAT_KEY);if (sessionObj != null) {Map<String, Object> sessionMap = (Map<String, Object>) sessionObj;if (sessionMap.containsKey(url)) {Map<String, Object> preDataMap = (Map<String, Object>) sessionMap.get(url);if (compareParams(nowDataMap, preDataMap) && compareTime(nowDataMap, preDataMap, annotation.interval())) {return true;}}}Map<String, Object> sessionMap = new HashMap<String, Object>();sessionMap.put(url, nowDataMap);session.setAttribute(SESSION_REPEAT_KEY, sessionMap);return false;}/*** 判断参数是否相同*/private boolean compareParams(Map<String, Object> nowMap, Map<String, Object> preMap) {String nowParams = (String) nowMap.get(REPEAT_PARAMS);String preParams = (String) preMap.get(REPEAT_PARAMS);return nowParams.equals(preParams);}/*** 判断两次间隔时间*/private boolean compareTime(Map<String, Object> nowMap, Map<String, Object> preMap, int interval) {long time1 = (Long) nowMap.get(REPEAT_TIME);long time2 = (Long) preMap.get(REPEAT_TIME);if ((time1 - time2) < interval) {return true;}return false;}
}

3、定义注解

/*** 自定义注解防止表单重复提交**/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RepeatSubmit {/*** 间隔时间(ms)，小于此时间视为重复提交*/public int interval() default 5000;/*** 提示消息*/public String message() default "不允许重复提交，请稍后再试";
}

4、注册拦截器

@Configuration
public class WebMvcConfiguration implements WebMvcConfigurer {@Autowiredprivate RepeatSubmitInterceptor repeatSubmitInterceptor;@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(repeatSubmitInterceptor).addPathPatterns("/api/**");}
}

5、使用

@RestController
public class RegController {@PostMapping("/api/reguser")@RepeatSubmitpublic String regUser(){return "success";}
}