利用Spring拦截器实现防止表单重复提交

一、主要流程

1.自定义拦截器，拦截所有请求；

2.拦截器中获取放重复提交自定义注解；

3.根据url+参数来判断是否为重复提交；

4.重复则拦截否则放行。

---

二、代码实现

1. 注解

@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";
}

2. 防重复提交抽象拦截器

/**
 * 防止重复提交拦截器
 *
 * @author ruoyi
 */
@Component
public abstract class RepeatSubmitInterceptor implements HandlerInterceptor
{
    @Override
    public 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))
                {
                    AjaxResult ajaxResult = AjaxResult.error(annotation.message());
                    ServletUtils.renderString(response, JSON.marshal(ajaxResult));
                    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;
}

3. 防重复拦截器实现类

/**
 * 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。
 * 此处是单体项目，所以用的session来存，若非单体则可利用token+redis来实现相同效果
 * 
 */
@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";

    @SuppressWarnings("unchecked")
    @Override
    public boolean isRepeatSubmit(HttpServletRequest request, RepeatSubmit annotation) throws Exception
    {
        // 本次参数及系统时间
        String nowParams = JSON.marshal(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;
    }
}