import com.yunling.sys.config.exception.ParamValidateException;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Component;
import org.springframework.util.ObjectUtils;
import javax.annotation.Resource;
import java.util.concurrent.TimeUnit;
/**
 * Redis工具類(lèi)
 *
 * @author 譚永強(qiáng)
 * @date 2023-08-15
 */
@Component
public class RedisUtils {
    @Resource
    private RedisTemplate<String, Object> redisTemplate;
    /**
     * 寫(xiě)入緩存
     *
     * @param key   建
     * @param value 值
     * @return 成功/失敗
     */
    public boolean set(final String key, Object value) {
        boolean result = false;
        try {
            ValueOperations<String, Object> operations = redisTemplate.opsForValue();
            operations.set(key, value);
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
    /**
     * 寫(xiě)入緩存設(shè)置時(shí)效時(shí)間
     *
     * @param key   鍵
     * @param value 值
     * @return 成功/失敗
     */
    public boolean set(final String key, Object value, Long expireTime) {
        boolean result = false;
        try {
            ValueOperations<String, Object> operations = redisTemplate.opsForValue();
            operations.set(key, value);
            redisTemplate.expire(key, expireTime, TimeUnit.SECONDS);
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
    /**
     * 判斷緩存中是否有對(duì)應(yīng)的value
     *
     * @param key 鍵
     * @return 成功/失敗
     */
    public boolean exists(final String key) {
        return Boolean.TRUE.equals(redisTemplate.hasKey(key));
    }
    /**
     * 讀取緩存
     *
     * @param key 鍵
     * @return 成功/失敗
     */
    public Object get(final String key) {
        return redisTemplate.opsForValue().get(key);
    }
    /**
     * 刪除對(duì)應(yīng)的value
     *
     * @param key 鍵
     * @return 成功/失敗
     */
    public boolean remove(final String key) {
        if (exists(key)) {
            return Boolean.TRUE.equals(redisTemplate.delete(key));
        }
        return false;
    }
    /**
     * 遞增
     *
     * @param key   鍵
     * @param delta 要增加幾(大于0)
     * @return 結(jié)果
     */
    public Long incr(String key, long delta) {
        if (ObjectUtils.isEmpty(key)) {
            throw new ParamValidateException("key值不能為空");
        }
        if (delta < 0) {
            throw new ParamValidateException("遞增因子必須大于0");
        }
        return redisTemplate.opsForValue().increment(key, delta);
    }
    /**
     * 遞減
     *
     * @param key   鍵
     * @param delta 要減少幾(小于0)
     * @return 結(jié)果
     */
    public Long decr(String key, long delta) {
        if (ObjectUtils.isEmpty(key)) {
            throw new ParamValidateException("key值不能為空");
        }
        if (delta < 0) {
            throw new ParamValidateException("遞減因子必須大于0");
        }
        return redisTemplate.opsForValue().increment(key, -delta);
    }
}

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
 * 自動(dòng)冪等
 * 該注解加在需要冪等的方法上，即可自動(dòng)上線(xiàn)方法的冪等。
 *
 * @author 譚永強(qiáng)
 * @date 2023-08-15
 */
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AutoIdempotent {
    /**
     * 限定時(shí)間(秒)
     * 限制多少秒內(nèi)，每個(gè)用戶(hù)只能請(qǐng)求一次該接口。
     */
    long seconds() default 1;
}

import com.alibaba.fastjson.JSON;
import com.alibaba.nacos.common.utils.MD5Utils;
import com.yunling.sys.annotate.AutoIdempotent;
import com.yunling.sys.common.RedisUtils;
import com.yunling.sys.common.ResultData;
import com.yunling.sys.common.ReturnCode;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.util.ObjectUtils;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Objects;
/**
 * 自動(dòng)冪等攔截器
 *
 * @author 譚永強(qiáng)
 * @date 2023-08-15
 */
@Component
public class AutoIdempotentInterceptor extends HandlerInterceptorAdapter {
    @Resource
    private RedisUtils redisUtils;
    /**
     * @param request  請(qǐng)求
     * @param response 響應(yīng)
     * @param handler  處理
     * @return 結(jié)果
     * @throws Exception 異常
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //判斷請(qǐng)求是否為方法的請(qǐng)求
        if (!(handler instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod method = (HandlerMethod) handler;
        //獲取方法中是否有冪等性注解
        AutoIdempotent anno = method.getMethodAnnotation(AutoIdempotent.class);
        //若注解為空則直接返回
        if (Objects.isNull(anno)) {
            return true;
        }
        //限定時(shí)間
        long seconds = anno.seconds();
        //token
        String token = request.getHeader(HttpHeaders.AUTHORIZATION);
        if (Objects.isNull(token)) {
            ResultData<String> resultData = ResultData.fail(ReturnCode.ACCESS_DENIED.getCode(), "token不能為空");
            write(response, JSON.toJSONString(resultData));
            return false;
        }
        //此處轉(zhuǎn)MD5的原因就是token長(zhǎng)度太長(zhǎng)了，轉(zhuǎn)成md5短一些，此操作并不是必須的
        String md5 = MD5Utils.md5Hex(token, StandardCharsets.UTF_8.toString());
        //使用token+method+uri作為key值，此處需要通過(guò)key值確定請(qǐng)求的唯一性，也可以使用其他的組合，只要保證唯一性即可
        String key = md5 + ":" + request.getMethod() + ":" + request.getRequestURI();
        Object requestCountObj = redisUtils.get(key);
        if (!ObjectUtils.isEmpty(requestCountObj)) {
            //不為空，說(shuō)明不是第一次請(qǐng)求，直接報(bào)錯(cuò)
            ResultData<String> resultData = ResultData.fail(ReturnCode.RC206.getCode(), "請(qǐng)求已提交，請(qǐng)勿重復(fù)請(qǐng)求");
            write(response, JSON.toJSONString(resultData));
            return false;
        }
        //若為空則為第一次請(qǐng)求
        return redisUtils.set(key, 1, seconds);
    }
    /**
     * 返回結(jié)果到前端
     *
     * @param response 響應(yīng)
     * @param body     結(jié)果
     * @throws IOException 異常
     */
    private void write(HttpServletResponse response, String body) throws IOException {
        response.setContentType(MediaType.APPLICATION_JSON_VALUE);
        ServletOutputStream os = response.getOutputStream();
        os.write(body.getBytes());
        os.flush();
        os.close();
    }
}

package com.yunling.sys.config;
import com.yunling.sys.config.interceptor.AutoIdempotentInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import javax.annotation.Resource;
/**
 * 將攔截器注入到容器中
 *
 * @author 譚永強(qiáng)
 * @date 2023-08-15
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Resource
    private AutoIdempotentInterceptor autoIdempotentInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(autoIdempotentInterceptor);
    }
}

@RestController
@RequestMapping("user")
public class SysUserController {
    /**
     * 用戶(hù)新增
     *
     * @param user 用戶(hù)信息
     */
    @AutoIdempotent(seconds = 60)
    @PostMapping("add")
    public void add(@RequestBody SysUser user) {
       //業(yè)務(wù)代碼.....
    }
}