统一返回结果类以及常量类

public class Constants {

    // 成功状态码
    public static final Integer SUCCESS_CODE = 200;
    // 失败状态码
    public static final Integer FAILURE_CODE = 404;
    // Token过期状态码
    public static final Integer TOKEN_EXPIRED = 401;

    // 成功消息
    public static final String SUCCESS_MESSAGE = "ok";
    // 失败消息
    public static final String FAILURE_MESSAGE = "fail";

    // 未授权消息
    public static final String UNAUTHORIZED_MESSAGE = "未授权";
    // 禁止访问消息
    public static final String FORBIDDEN_MESSAGE = "禁止访问";
    // 未找到资源消息
    public static final String NOT_FOUND_MESSAGE = "未找到资源";
    // 方法不允许消息
    public static final String METHOD_NOT_ALLOWED_MESSAGE = "方法不允许";
    // 不可接受的内容消息
    public static final String NOT_ACCEPTABLE_MESSAGE = "不可接受的内容";
    // 资源冲突消息
    public static final String CONFLICT_MESSAGE = "资源冲突";
    // 资源已不存在消息
    public static final String GONE_MESSAGE = "资源已不存在";
    // 请求无法处理消息
    public static final String UNPROCESSABLE_ENTITY_MESSAGE = "请求无法处理";
    // 服务器内部错误消息
    public static final String INTERNAL_SERVER_ERROR_MESSAGE = "服务器内部错误";
    // 功能未实现消息
    public static final String NOT_IMPLEMENTED_MESSAGE = "功能未实现";
    // 网关错误消息
    public static final String BAD_GATEWAY_MESSAGE = "网关错误";
    // 服务不可用消息
    public static final String SERVICE_UNAVAILABLE_MESSAGE = "服务不可用";
    // 网关超时消息
    public static final String GATEWAY_TIMEOUT_MESSAGE = "网关超时";
}

public class Result<T> {
    private String message;
    private Integer code;
    private T data;

    // 默认构造函数
    public Result() {
    }

    // 修改构造函数参数顺序，data放在中间
    public Result(Integer code, T data, String message) {
        this.code = code;
        this.data = data;
        this.message = message;
    }

    // Getter和Setter方法
    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

    public static <T> Result<T> ok(T data) {
        return new Result<T>(Constants.SUCCESS_CODE, data, Constants.SUCCESS_MESSAGE);
    }

    // 修改返回方法参数顺序，如果有data则放在中间
    public static <T> Result<T> ok(Integer code, T data, String message) {
        return new Result<T>(code, data, message);
    }

    public static <T> Result<T> fail() {
        return new Result<T>(Constants.FAILURE_CODE, null, Constants.FAILURE_MESSAGE);
    }

    public static <T> Result<T> fail(String message) {
        return new Result<T>(Constants.FAILURE_CODE, null, message);
    }

    public static <T> Result<T> fail(Integer code, String message) {
        return new Result<T>(code, null, message);
    }

    public static <T> Result<T> fail(Integer code, String message, T data) {
        return new Result<T>(code, data, message);
    }
}