package com.langjialing.helloworld.config.response;

/**
 * @author 郎家岭伯爵
 * @time 2023/3/31 14:07
 */

import lombok.AllArgsConstructor;
import lombok.Getter;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
 * @author pdai
 */
@Getter
@AllArgsConstructor
public enum ResponseStatus {

    SUCCESS("200", "success"),
    FAIL("500", "failed"),

    HTTP_STATUS_200("200", "ok"),
    HTTP_STATUS_400("400", "request error"),
    HTTP_STATUS_401("401", "no authentication"),
    HTTP_STATUS_403("403", "no authorities"),
    HTTP_STATUS_500("500", "server error");

    public static final List<ResponseStatus> HTTP_STATUS_ALL = Collections.unmodifiableList(
            Arrays.asList(HTTP_STATUS_200, HTTP_STATUS_400, HTTP_STATUS_401, HTTP_STATUS_403, HTTP_STATUS_500
            ));

    /**
     * response code
     */
    private final String responseCode;

    /**
     * description.
     */
    private final String description;

}

package com.langjialing.helloworld.config.response;

import lombok.Builder;
import lombok.Data;

import java.io.Serializable;

/**
 * @author 郎家岭伯爵
 * @time 2023/3/31 14:09
 */
@Data
@Builder
public class ResponseResult<T> {

    /**
     * response timestamp.
     */
    private long timestamp;

    /**
     * response code, 200 -> OK.
     */
    private String status;

    /**
     * response message.
     */
    private String message;

    /**
     * response data.
     */
    private T data;

    /**
     * response success result wrapper.
     *
     * @param <T> type of data class
     * @return response result
     */
    public static <T> ResponseResult<T> success() {
        return success(null);
    }

    /**
     * response success result wrapper.
     *
     * @param data response data
     * @param <T>  type of data class
     * @return response result
     */
    public static <T> ResponseResult<T> success(T data) {
        return ResponseResult.<T>builder().data(data)
                .message(ResponseStatus.SUCCESS.getDescription())
                .status(ResponseStatus.SUCCESS.getResponseCode())
                .timestamp(System.currentTimeMillis())
                .build();
    }

    /**
     * response error result wrapper.
     *
     * @param message error message
     * @param <T>     type of data class
     * @return response result
     */
    public static <T extends Serializable> ResponseResult<T> fail(String message) {
        return fail(null, message);
    }

    /**
     * response error result wrapper.
     *
     * @param data    response data
     * @param message error message
     * @param <T>     type of data class
     * @return response result
     */
    public static <T> ResponseResult<T> fail(T data, String message) {
        return ResponseResult.<T>builder().data(data)
                .message(message)
                .status(ResponseStatus.FAIL.getResponseCode())
                .timestamp(System.currentTimeMillis())
                .build();
    }

}

package com.langjialing.helloworld.controller;

import com.langjialing.helloworld.config.response.ResponseResult;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections4.map.LRUMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author 郎家岭伯爵
 * @time 2023/3/22 9:30
 */
@RestController
@Slf4j
public class UserController {

    /**
     * 最大容量 100 个，根据 LRU 算法淘汰数据的 Map 集合
     */
    private LRUMap<String, Integer> reqCache = new LRUMap<>(100);

    @GetMapping("/add")
    public ResponseResult<String> addUser(@RequestParam String userId){

        // 非空判断(忽略)...
        synchronized (this.getClass()) {
            // 重复请求判断
            if (reqCache.containsKey(userId)) {
                // 重复请求
                log.info("请勿重复提交：{}", userId);
                return ResponseResult.fail("400","执行失败！");
            }
            // 存储请求 ID
            reqCache.put(userId, 1);
        }
        // 业务代码...
        log.info("成功添加用户:{}", userId);
//        return "执行成功！";
        return ResponseResult.success("执行成功！");
    }
}