RepeatSubmit作用

同一个用户的统一操作， 在规定的时间内 只能做一次相同数据的请求，防止重复提交，超时重试等一些问题

RepeatSubmit使用注意事项

查询和删除是天然的幂等操作，故一般不建议使用。在有更新和写入的操作时，建议使用，例如订单提交，修改订单状态。
幂等性: 多次执行的结果和一次执行成功的结果对资源的作用是相同的，这里的资源一般指的是数据库的数据。

使用

interval 间隔时间 默认单位是ms message 为默认返回信息

@RepeatSubmit(interval = 10000,message = "不能重复提交")

解决方案

程序控制和资源(数据)控制

ruoyi 脚手架的实现

使用 拦截器 + 过滤器 实现的

1. 拦截器 : 对 带有RepeatSubmit 接口进行重复性校验，将 ( key标识 + 请求url + base64（用户请求数据）) 作为key，时间戳 + 请求数据 组成map 作为value， 当然了 key 可以自行进行修改 。
2. 过滤器: 对请求进行过滤，将请求转化为可重复读取inputStream的request。

具体代码如下（本人已修改）:

package com.example.interceptor;

import java.lang.annotation.*;

/**
 * 自定义注解防止表单重复提交
 * 建议查询和删除不要使用此注解。
 * @author ruoyi
 *
 */
@Inherited
@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，请稍候再试";
}

1. 定义拦截器

package com.example.interceptor;


import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * 防止重复提交拦截器
 *
 * @author ruoyi
 */
@Component
@Slf4j
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))
                {

                    log.info("重复提交了!!!可自行定义返回格式");
                    // 重复提交了
//                    AjaxResult ajaxResult = AjaxResult.error(annotation.message());
//                    ServletUtils.renderString(response, JSON.toJSONString(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 请求信息
     * @param annotation 防重复注解参数
     * @return 结果
     * @throws Exception
     */
    public abstract boolean isRepeatSubmit(HttpServletRequest request, RepeatSubmit annotation);
}

2. 具体实现机制
   可自定义key

package com.example.interceptor.impl;

import com.alibaba.fastjson2.JSON;

import com.example.interceptor.RepeatSubmit;
import com.example.interceptor.RepeatSubmitInterceptor;
import com.example.interceptor.RepeatedlyRequestWrapper;
import com.example.util.redis.RedisCache;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import sun.misc.BASE64Encoder;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * 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
 */
@Slf4j
@Component
public class SameUrlDataInterceptor extends RepeatSubmitInterceptor
{
    public final String REPEAT_PARAMS = "repeatParams";

    public final String REPEAT_TIME = "repeatTime";

    /**
     * 防重提交 redis key
     */
    public final String REPEAT_SUBMIT_KEY = "repeat_submit:";

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

    @Autowired
    private RedisCache redisCache;

    @SuppressWarnings("unchecked")
    @Override
    public boolean isRepeatSubmit(HttpServletRequest request, RepeatSubmit annotation)
    {

        BASE64Encoder encoder = new BASE64Encoder();
        String nowParams = "";
        if (request instanceof RepeatedlyRequestWrapper)
        {
            // 注意 一定要使用过滤器 将 request 转换为 RepeatedlyRequestWrapper 不然无法获取请求参数
            RepeatedlyRequestWrapper repeatedlyRequest = (RepeatedlyRequestWrapper) request;
            nowParams = getBodyString(repeatedlyRequest);
        }

        // body参数为空，获取Parameter的数据  nowParams
        if ("".equals(nowParams.trim()))
        {
            nowParams = JSON.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();

        String str = request.getHeader(header);
        // 唯一值（没有消息头则使用请求地址）
        String submitKey =  str == null ? "" : str.trim();

        // 可以获取 不同的 IP地址 或者 mac地址 进行 主机识别  加上此注解的 通过id查询可能会受影响 所以建议查询和删除不要使用此注解即可。
        // 使用 BASE64 对 submitKey 和 请求数据 加密
        String dataEncryption = encoder.encode((submitKey+nowParams).getBytes(StandardCharsets.UTF_8));
        // 唯一标识（指定key + url + 请求数据 ）
        String cacheRepeatKey = REPEAT_SUBMIT_KEY + url + dataEncryption;


        Object sessionObj = redisCache.getCacheObject(cacheRepeatKey);
        // 判断 redis 中 有无重复的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);
                // 比较 请求参数    判断间隔时间 是否有效
                if (compareParams(nowDataMap, preDataMap) && compareTime(nowDataMap, preDataMap, annotation.interval()))
                {
                    return true;
                }
            }
        }
        Map<String, Object> cacheMap = new HashMap<String, Object>();
        cacheMap.put(url, nowDataMap);
        redisCache.setCacheObject(cacheRepeatKey, cacheMap, annotation.interval(), TimeUnit.MILLISECONDS);
        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;
    }

    public String getBodyString(ServletRequest request)
    {
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = null;
        try (InputStream inputStream = request.getInputStream())
        {
            reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
            String line = "";
            while ((line = reader.readLine()) != null)
            {
                sb.append(line);
            }
        }
        catch (IOException e)
        {
            log.warn("getBodyString出现问题！");
        }
        finally
        {
            if (reader != null)
            {
                try
                {
                    reader.close();
                }
                catch (IOException e)
                {
                    log.error("关闭文件错误");
                }
            }
        }
        return sb.toString();
    }
}

3. 可重复读取inputStream的request

package com.example.interceptor;



import lombok.extern.slf4j.Slf4j;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.StandardCharsets;

/**
 * 构建可重复读取inputStream的request
 * 
 * @author ruoyi
 */
@Slf4j
public class RepeatedlyRequestWrapper extends HttpServletRequestWrapper
{
    private final byte[] body;

    public RepeatedlyRequestWrapper(HttpServletRequest request, ServletResponse response) throws IOException
    {
        super(request);
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");

        body = getBodyString(request).getBytes(StandardCharsets.UTF_8);
    }

    @Override
    public BufferedReader getReader() throws IOException
    {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
    public ServletInputStream getInputStream() throws IOException
    {
        final ByteArrayInputStream bais = new ByteArrayInputStream(body);
        return new ServletInputStream()
        {
            @Override
            public int read() throws IOException
            {
                return bais.read();
            }

            @Override
            public int available() throws IOException
            {
                return body.length;
            }

            @Override
            public boolean isFinished()
            {
                return false;
            }

            @Override
            public boolean isReady()
            {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener)
            {

            }
        };
    }

    public String getBodyString(ServletRequest request)
    {
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = null;
        try (InputStream inputStream = request.getInputStream())
        {
            reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
            String line = "";
            while ((line = reader.readLine()) != null)
            {
                sb.append(line);
            }
        }
        catch (IOException e)
        {
            log.warn("getBodyString出现问题！");
        }
        finally
        {
            if (reader != null)
            {
                try
                {
                    reader.close();
                }
                catch (IOException e)
                {
                    log.error("关闭文件错误");
                }
            }
        }
        return sb.toString();
    }
}

4. 将拦截器注册进入系统配置中

package com.example.interceptor;

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.WebMvcConfigurer;



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

    /**
     * 自定义拦截规则
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        // 把重复校验添加到系统配置中
        // 重复校验拦截所有请求   自行判断是否重复校验 有注解则校验 没有则不校验
        registry.addInterceptor(repeatSubmitInterceptor).addPathPatterns("/**");
    }

    /**
     * 跨域配置
     */
    @Bean
    public CorsFilter corsFilter()
    {
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        // 设置访问源地址
        config.addAllowedOriginPattern("*");
        // 设置访问源请求头
        config.addAllowedHeader("*");
        // 设置访问源请求方法
        config.addAllowedMethod("*");
        // 有效期 1800秒
        config.setMaxAge(1800L);
        // 添加映射路径，拦截一切请求
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", config);
        // 返回新的CorsFilter
        return new CorsFilter(source);
    }
}

5. 定义过滤器

package com.example.filter;

import com.example.interceptor.RepeatedlyRequestWrapper;
import org.springframework.http.MediaType;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * Repeatable 过滤器
 * 
 * @author ruoyi
 */
public class RepeatableFilter implements Filter
{

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException
    {
        ServletRequest requestWrapper = null;
        if (request instanceof HttpServletRequest
                && startsWithIgnoreCase(request.getContentType(), MediaType.APPLICATION_JSON_VALUE))
        {
            requestWrapper = new RepeatedlyRequestWrapper((HttpServletRequest) request, response);
        }
        if (null == requestWrapper)
        {
            chain.doFilter(request, response);
        }
        else
        {
            chain.doFilter(requestWrapper, response);
        }
    }


    public static boolean startsWithIgnoreCase(CharSequence str, CharSequence prefix) {
        return startsWith(str, prefix);
    }

    private static boolean startsWith(CharSequence str, CharSequence prefix) {
        if (str != null && prefix != null) {
            int preLen = prefix.length();
            return preLen <= str.length() && regionMatches(str, prefix, preLen);
        } else {
            return str == prefix;
        }
    }

    static boolean regionMatches(CharSequence cs, CharSequence substring, int length) {
        if (cs instanceof String && substring instanceof String) {
            return ((String)cs).regionMatches(true, 0, (String)substring, 0, length);
        } else {
            int index1 = 0;
            int index2 = 0;
            int tmpLen = length;
            int srcLen = cs.length();
            int otherLen = substring.length();
            if (length >= 0) {
                if (srcLen >= length && otherLen >= length) {
                    while(tmpLen-- > 0) {
                        char c1 = cs.charAt(index1++);
                        char c2 = substring.charAt(index2++);
                        if (c1 != c2) {

                            char u1 = Character.toUpperCase(c1);
                            char u2 = Character.toUpperCase(c2);
                            if (u1 != u2 && Character.toLowerCase(u1) != Character.toLowerCase(u2)) {
                                return false;
                            }
                        }
                    }

                    return true;
                } else {
                    return false;
                }
            } else {
                return false;
            }
        }
    }
}

6. 将过滤器注册进入系统中

package com.example.filter;


import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


/**
 * Filter配置
 *
 * @author ruoyi
 */
@Configuration
public class FilterConfig
{
    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Bean
    public FilterRegistrationBean someFilterRegistration()
    {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new RepeatableFilter());
        registration.addUrlPatterns("/*");
        registration.setName("repeatableFilter");
        registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE);
        return registration;
    }
}