java项目springboot后端怎么防止前端重复提交表单-通过注解实现-redis版

前端提交表单按钮如果不小心按了两次或者多次，那么表单数据就被重复插入数据库，尤其是网络延时的情况下，多次点击提交按钮是常有的事，那么后端怎么来避免这个问题呢，最好的办法就是通过注解+拦截器验证重复的表单

1、添加注解接口

@Inherited
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RepeatSubmit
{

}

2、添加RepeatSubmitInterceptor防止重复提交拦截器，验证是否重复提交由子类实现具体的防重复提交的规则

/**
 * 防止重复提交拦截器
 *
 * @author driver-IT
 */
@Component
public abstract class RepeatSubmitInterceptor extends HandlerInterceptorAdapter
{
    @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))
                {
                    AjaxResult ajaxResult = AjaxResult.error("不允许重复提交，请稍后再试");
                    ServletUtils.renderString(response, JSONObject.toJSONString(ajaxResult));
                    return false;
                }
            }
            return true;
        }
        else
        {
            return super.preHandle(request, response, handler);
        }
    }

    /**
     * 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 httpServletRequest
     * @return
     * @throws Exception
     */
    public abstract boolean isRepeatSubmit(HttpServletRequest request);
}

3、添加子类实现具体的防重复提交的规则

/**
 * 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。
 * 
 * @author driver-IT
 */
@Component
public class SameUrlDataInterceptor extends RepeatSubmitInterceptor
{
    public final String REPEAT_PARAMS = "repeatParams";

    public final String REPEAT_TIME = "repeatTime";

    public final String CACHE_REPEAT_KEY = "repeatData";

    @Autowired
    private RedisCache redisCache;

    /**
     * 间隔时间，单位:秒 默认10秒
     * 
     * 两次相同参数的请求，如果间隔时间大于该参数，系统不会认定为重复提交的数据
     */
    private int intervalTime = 10;

    public void setIntervalTime(int intervalTime)
    {
        this.intervalTime = intervalTime;
    }

    @SuppressWarnings("unchecked")
    @Override
    public boolean isRepeatSubmit(HttpServletRequest request)
    {
        RepeatedlyRequestWrapper repeatedlyRequest = (RepeatedlyRequestWrapper) request;
        String nowParams = HttpHelper.getBodyString(repeatedlyRequest);

        // body参数为空，获取Parameter的数据
        if (StringUtils.isEmpty(nowParams))
        {
            nowParams = JSONObject.toJSONString(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cache的key值）
        String url = request.getRequestURI();

        Object sessionObj = redisCache.getCacheObject(CACHE_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))
                {
                    return true;
                }
            }
        }
        Map<String, Object> cacheMap = new HashMap<String, Object>();
        cacheMap.put(url, nowDataMap);
        redisCache.setCacheObject(CACHE_REPEAT_KEY, cacheMap, intervalTime, TimeUnit.SECONDS);
        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)
    {
        long time1 = (Long) nowMap.get(REPEAT_TIME);
        long time2 = (Long) preMap.get(REPEAT_TIME);
        if ((time1 - time2) < (this.intervalTime * 1000))
        {
            return true;
        }
        return false;
    }

4、找到你要防止重复提交的接口controller中添加这个注解，搞定收工，亲测有效

/**
     * 新增设备
     */
    @RepeatSubmit
    @ApiOperation("新增设备")
    @ApiImplicitParam(name = "device", value = "新增设备信息", dataType = "Device")
    @PreAuthorize("@ss.hasPermi('dev:device:add')")
    @PostMapping
    public AjaxResult add(@RequestBody Device device)
    {
        if (device == null || device.getDeptId() == null) {
            return AjaxResult.error("请选择部门");
        }
        LoginUser loginUser = tokenService.getLoginUser(ServletUtils.getRequest());
        if (!deptService.hasChildOrSelfByDeptId(device.getDeptId(), loginUser.getUser().getDeptId())) {
            return new AjaxResult(409, "不允许跨区域操作");
        }
        return toAjax(deviceService.insertDevice(device));
    }