public interface CommonConstants {

    /**
     * 成功标记
     */
    Integer SUCCESS = 0;
    /**
     * 失败标记
     */
    Integer FAIL = 1;

}

public class R<T> implements Serializable {

    private static final long serialVersionUID = 1L;

    @Getter
    @Setter
    @ApiModelProperty(value = "返回操作码 0成功 1失败")
    private int code;

    @Getter
    @Setter
    @ApiModelProperty(value = "操作提示")
    private String msg;

    @Getter
    @Setter
    @ApiModelProperty(value = "返回数据")
    private T data;

    public static <T> R<T> ok() {
        return restResult(null, CommonConstants.SUCCESS, null);
    }

    public static <T> R<T> ok(T data) {
        return restResult(data, CommonConstants.SUCCESS, null);
    }

    public static <T> R<T> ok(T data, String msg) {
        return restResult(data, CommonConstants.SUCCESS, msg);
    }

    public static <T> R<T> failed() {
        return restResult(null, CommonConstants.FAIL, null);
    }

    public static <T> R<T> failed(String msg) {
        return restResult(null, CommonConstants.FAIL, msg);
    }

    public static <T> R<T> failed(T data) {
        return restResult(data, CommonConstants.FAIL, null);
    }

    public static <T> R<T> failed(T data, String msg) {
        return restResult(data, CommonConstants.FAIL, msg);
    }

    private static <T> R<T> restResult(T data, int code, String msg) {
        R<T> apiResult = new R<>();
        apiResult.setCode(code);
        apiResult.setData(data);
        apiResult.setMsg(msg);
        return apiResult;
    }
}