防止重复提交

指定对某些请求进行重复提交校验。避免同一客户在指定时间内重复提交同样的请求(参数一样)。

采用的方式：注解+拦截器+REDIS

1.自定义注解

@Inherited
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RepeatSubmit
{
    int intervalTime() default 3;  // 多长时间内同一客户重复提交同样的请求算重复提交 单位秒  1-9之间
}

2.创建拦截器

2.1找到被注解RepeatSubmit注解的请求

package com.ruoyi.framework.interceptor;

import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import com.alibaba.fastjson.JSONObject;
import com.ruoyi.common.annotation.RepeatSubmit;
import com.ruoyi.common.core.domain.AjaxResult;
import com.ruoyi.common.utils.ServletUtils;

/**
 * 防止重复提交拦截器
 *
 * @author ruoyi
 */
@Component
public abstract class RepeatSubmitInterceptor extends HandlerInterceptorAdapter
{

    /**
     * 间隔时间，单位:秒 默认3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
     */
    public int intervalTime = 3;

    @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);//是否被@RepeatSubmit注解
            if (annotation != null)
            {
                int i = annotation.intervalTime();  //获取注解RepeatSubmit的参数intervalTime
                if(i > 0 && i < 10){ //intervalTime我这里控制在0到9之间
                    intervalTime = i;
                }
                if(i >= 10){
                    intervalTime = 9;//intervalTime我这里控制在0到9之间
                }
                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 request
     * @return
     * @throws Exception
     */
    public abstract boolean isRepeatSubmit(HttpServletRequest request);
}

2.2判断是否是同一请求

package com.ruoyi.framework.interceptor.impl;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import javax.servlet.http.HttpServletRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSONObject;
import com.ruoyi.common.constant.Constants;
import com.ruoyi.common.core.redis.RedisCache;
import com.ruoyi.common.filter.RepeatedlyRequestWrapper;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.common.utils.http.HttpHelper;
import com.ruoyi.framework.interceptor.RepeatSubmitInterceptor;

/**
 * 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 ruoyi
 */
@Component
public class SameUrlDataInterceptor extends RepeatSubmitInterceptor
{
    public final String REPEAT_PARAMS = "repeatParams";

    public final String REPEAT_TIME = "repeatTime";

    // 令牌自定义标识
    @Value("${token.header}")
    private String header;

    @Autowired
    private RedisCache redisCache;


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

    @SuppressWarnings("unchecked")
    @Override
    public boolean isRepeatSubmit(HttpServletRequest request)
    {
        String nowParams = "";
        if (request instanceof RepeatedlyRequestWrapper)
        {
            RepeatedlyRequestWrapper repeatedlyRequest = (RepeatedlyRequestWrapper) request;
            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();

        // 唯一值（没有消息头则使用请求地址）
        String submitKey = request.getHeader(header);
        if (StringUtils.isEmpty(submitKey))
        {
            submitKey = url;
        }

        // 唯一标识（指定key + 消息头）
        String cache_repeat_key = Constants.REPEAT_SUBMIT_KEY + submitKey;

        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;
    }
}

3.配置拦截器

package com.ruoyi.framework.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import com.ruoyi.common.config.RuoYiConfig;
import com.ruoyi.common.constant.Constants;
import com.ruoyi.framework.interceptor.RepeatSubmitInterceptor;

/**
 * 通用配置
 * 
 * @author ruoyi
 */
@Configuration
public class ResourcesConfig implements WebMvcConfigurer
{
    @Autowired
    private RepeatSubmitInterceptor repeatSubmitInterceptor;

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry)
    {
        /** 本地文件上传路径 */
        registry.addResourceHandler(Constants.RESOURCE_PREFIX + "/**").addResourceLocations("file:" + RuoYiConfig.getProfile() + "/");

        /** swagger配置 */
        registry.addResourceHandler("swagger-ui.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
    }

    /**
     * 自定义拦截规则
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        registry.addInterceptor(repeatSubmitInterceptor).addPathPatterns("/**");
    }

    /**
     * 跨域配置
     */
    @Bean
    public CorsFilter corsFilter()
    {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        // 设置访问源地址
        config.addAllowedOrigin("*");
        // 设置访问源请求头
        config.addAllowedHeader("*");
        // 设置访问源请求方法
        config.addAllowedMethod("*");
        // 对接口配置跨域设置
        source.registerCorsConfiguration("/**", config);
        return new CorsFilter(source);
    }
}

4.使用

    //在controller的方法上加上@RepeatSubmit注解，这个方法就会去做重复提交校验
　　 @PostMapping ("/addOrder")
    @RepeatSubmit(intervalTime = 9)
    public AjaxResult addOrder(@RequestBody DistinctOrderParamNew distinctOrderParamNew) throws ParseException, OutOfStockException {
            AjaxResult ta =  ljOrderAddNewService.addOrder(distinctOrderParamNew);
            return ta;
    }
}