全球速递！Springboot利用Redis实现接口幂等性拦截

2022-06-24 06:05:08 来源 : 软件开发网

前言

(资料图片)

正文

实战开始

核心三件套

工具类三件套

REDIS配置类

前言

近期一个老项目出现了接口幂等性校验问题，前端加了按钮置灰，

依然被人拉着接口参数一顿输出，还是重复调用了接口，小陈及时赶到现场，通过复制粘贴，完成了后端接口幂等性调用校验。

以前写过一篇关于接口简单限流防止重复调用的，但是跟该篇还是不一样的，该篇的角度是接口和参数整体一致才当做重复。

简单限流：Springboot使用redis实现接口Api限流的实例

该篇内容：

实现接口调用的幂等性校验

方案：自定义注解+redis+拦截器+MD5 实现

草图，意会（用户标识不是必要，看业务场景是针对个人还是只针对接口&参数）：

话不多说，开始实战。

PS：前排提醒，如果你还不知道怎么springboot整合redis，可以先去看下redis使用系列的一、二。

SpringBoot中对应2.0.x版本的Redis配置详解

SpringBoot整合Redis之编写RedisConfig

正文

自定义注解怎么玩的：

①标记哪个接口需要进行幂等性拦截

②每个接口可以要求幂等性范围时间不一样，举例：可以2秒内，可以3秒内，时间自己传

③ 一旦触发了，提示语可以不同，举例：VIP的接口，普通用户的接口，提示语不一样（开玩笑）

效果：

实战开始核心三件套

注解、拦截器、拦截器配置

① RepeatDaMie.java

import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * @Author: JCccc * @Date: 2022-6-13 9:04 * @Description:  自定义注解,防止重复提交 */@Target({ElementType.METHOD})@Retention(RetentionPolicy.RUNTIME)public @interface RepeatDaMie {    /**     * 时间ms限制     */    public int second() default 1;    /**     * 提示消息     */    public String describe() default "重复提交了,兄弟";}

②ApiRepeatInterceptor.java

import com.example.repeatdemo.annotation.RepeatDaMie;import com.example.repeatdemo.util.ContextUtil;import com.example.repeatdemo.util.Md5Encrypt;import com.example.repeatdemo.util.RedisUtils;import com.example.repeatdemo.wrapper.CustomHttpServletRequestWrapper;import com.fasterxml.jackson.databind.ObjectMapper;import org.slf4j.Logger;import org.slf4j.LoggerFactory;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.io.IOException;import java.util.Objects;/** * @Author: JCccc * @Date: 2022-6-15 9:11 * @Description: 接口幂等性校验拦截器 */@Componentpublic class ApiRepeatInterceptor implements HandlerInterceptor {    private final Logger log = LoggerFactory.getLogger(this.getClass());    private static final String POST="POST";    private static final String GET="GET";    @Override    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {        try {            if (handler instanceof HandlerMethod) {                HandlerMethod handlerMethod = (HandlerMethod) handler;                // 获取RepeatDaMie注解                RepeatDaMie repeatDaMie = handlerMethod.getMethodAnnotation(RepeatDaMie.class);                if (null==repeatDaMie) {                    return true;                }                //限制的时间范围                int seconds = repeatDaMie.second();                //这个用户唯一标识，可以自己细微调整，是userId还是token还是sessionId还是不需要                String userUniqueKey = request.getHeader("userUniqueKey");                String method = request.getMethod();                String apiParams = "";                if (GET.equals(method)){                    log.info("GET请求来了");                    apiParams = new ObjectMapper().writeValueAsString(request.getParameterMap());                }else if (POST.equals(method)){                    log.info("POST请求来了");                    CustomHttpServletRequestWrapper wrapper = (CustomHttpServletRequestWrapper) request;                    apiParams = wrapper.getBody();                }               log.info("当前参数是：{}",apiParams);                // 存储key                String keyRepeatDaMie = Md5Encrypt.md5(userUniqueKey+request.getServletPath()+apiParams) ;                RedisUtils redisUtils = ContextUtil.getBean(RedisUtils.class);                if (Objects.nonNull(redisUtils.get(keyRepeatDaMie))){                   log.info("重复请求了，重复请求了，拦截了");                   returnData(response,repeatDaMie.describe());                   return false;               }else {                    redisUtils.setWithTime(keyRepeatDaMie, true,seconds);               }            }            return true;        } catch (Exception e) {            log.warn("请求过于频繁请稍后再试");            e.printStackTrace();        }        return true;    }    public void returnData(HttpServletResponse response,String msg) throws IOException {        response.setCharacterEncoding("UTF-8");        response.setContentType("application/json; charset=utf-8");        ObjectMapper objectMapper = new ObjectMapper();        //这里传提示语可以改成自己项目的返回数据封装的类        response.getWriter().println(objectMapper.writeValueAsString(msg));        return;    }}

③ WebConfig.java

import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;/** * @Author: JCccc * @Date: 2022-6-15 9:24 * @Description: */@Configurationpublic class WebConfig implements WebMvcConfigurer {    @Override    public void addInterceptors(InterceptorRegistry registry) {        registry.addInterceptor(new ApiRepeatInterceptor()).addPathPatterns("/**");    }}

工具类三件套

①ContextUtil.java

import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;import org.springframework.stereotype.Component;/** * @Author: JCccc * @Date: 2022-6-15 9:24 * @Description: */@Componentpublic final class ContextUtil implements ApplicationContextAware {    protected static ApplicationContext applicationContext ;    @Override    public void setApplicationContext(ApplicationContext arg0) throws BeansException {        if (applicationContext == null) {            applicationContext = arg0;        }    }    public static Object getBean(String name) {        //name表示其他要注入的注解name名        return applicationContext.getBean(name);    }    /**     * 拿到ApplicationContext对象实例后就可以手动获取Bean的注入实例对象     */    public static  T getBean(Class clazz) {        return applicationContext.getBean(clazz);    }}

②Md5Encrypt.java

import java.io.UnsupportedEncodingException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;/** * @Author: JCccc * @CreateTime: 2018-10-30 * @Description: */public class Md5Encrypt {    private static final char[] DIGITS = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a",            "b", "c", "d", "e", "f"};    /**     * 对字符串进行MD5加密     *     * @param text 明文     * @return 密文     */    public static String md5(String text) {        MessageDigest msgDigest = null;        try {            msgDigest = MessageDigest.getInstance("MD5");        } catch (NoSuchAlgorithmException e) {            throw new IllegalStateException("System doesn"t support MD5 algorithm.");        }        try {            // 注意该接口是按照指定编码形式签名            msgDigest.update(text.getBytes("UTF-8"));        } catch (UnsupportedEncodingException e) {            throw new IllegalStateException("System doesn"t support your  EncodingException.");        }        byte[] bytes = msgDigest.digest();        String md5Str = new String(encodeHex(bytes));        return md5Str;    }    private static char[] encodeHex(byte[] data) {        int l = data.length;        char[] out = new char[l << 1];        // two characters form the hex value.        for (int i = 0, j = 0; i < l; i++) {            out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];            out[j++] = DIGITS[0x0F & data[i]];        }        return out;    }}

③RedisUtils.java

import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.redis.core.*;import org.springframework.stereotype.Component;import java.io.Serializable;import java.util.List;import java.util.Set;import java.util.concurrent.TimeUnit;@Componentpublic class RedisUtils {    @Autowired    private RedisTemplate redisTemplate;    /**     * 写入String型 [ 键，值]     *     * @param key     * @param value     * @return     */    public boolean set(final String key, Object value) {        boolean result = false;        try {            ValueOperations operations = redisTemplate.opsForValue();            operations.set(key, value);            result = true;        } catch (Exception e) {            e.printStackTrace();        }        return result;    }    /**     * 写入String型,顺便带有过期时间 [ 键，值]     *     * @param key     * @param value     * @return     */    public boolean setWithTime(final String key, Object value,int seconds) {        boolean result = false;        try {            ValueOperations operations = redisTemplate.opsForValue();            operations.set(key, value,seconds, TimeUnit.SECONDS);            result = true;        } catch (Exception e) {            e.printStackTrace();        }        return result;    }    /**     * 批量删除对应的value     *     * @param keys     */    public void remove(final String... keys) {        for (String key : keys) {            remove(key);        }    }    /**     * 批量删除key     *     * @param pattern     */    public void removePattern(final String pattern) {        Set keys = redisTemplate.keys(pattern);        if (keys.size() > 0)            redisTemplate.delete(keys);    }    /**     * 删除对应的value     *     * @param key     */    public void remove(final String key) {        if (exists(key)) {            redisTemplate.delete(key);        }    }    /**     * 判断缓存中是否有对应的value     *     * @param key     * @return     */    public boolean exists(final String key) {        return redisTemplate.hasKey(key);    }    /**     * 读取缓存     *     * @param key     * @return     */    public Object get(final String key) {        Object result = null;        ValueOperations operations = redisTemplate.opsForValue();        result = operations.get(key);        return result;    }    /**     * 哈希 添加     * hash 一个键值(key->value)对集合     *     * @param key     * @param hashKey     * @param value     */    public void hmSet(String key, Object hashKey, Object value) {        HashOperations hash = redisTemplate.opsForHash();        hash.put(key, hashKey, value);    }    /**     * Hash获取数据     *     * @param key     * @param hashKey     * @return     */    public Object hmGet(String key, Object hashKey) {        HashOperations hash = redisTemplate.opsForHash();        return hash.get(key, hashKey);    }    /**     * 列表添加     * list:lpush key value1     *     * @param k     * @param v     */    public void lPush(String k, Object v) {        ListOperations list = redisTemplate.opsForList();        list.rightPush(k, v);    }    /**     * 列表List获取     * lrange： key 0 10 (读取的个数 从0开始 读取到下标为10 的数据)     *     * @param k     * @param l     * @param l1     * @return     */    public List