Result对象 + 统一异常处理

1. 错误异常码设计

1.1 统一异常码接口定义

/**
 * 统一异常码接口定义
 *
 * @author 王洪玉
 * @date 2018/11/11
 */

public interface ExceptionEnum {

    /**
     * 获取异常编码
     *
     * @return 异常码
     */
    Integer getCode();

    /**
     * 获取异常信息
     *
     * @return 异常信息
     */
    String getMessage();
}

1.2. 通用异常错误码Enum

/**
 * 全局异常错误码
 */
public enum ResultMsgEnum implements ExceptionEnum {

    // 请求成功
    SUCCESS(200,"成功"),
    // 服务器内部错误
    ERROR(500,"失败");

    private int code;
    private String message;

    ResultMsgEnum(int value, String text) {
        this.code = value;
        this.message = text;
    }

    @Override
    public Integer getCode() {
        return code;
    }

    @Override
    public String getMessage() {
        return message;
    }
}

1.3. 业务异常错误码Enum

/**
 * CMS系统错误异常码 5001**
 */
public enum CmsErrorCodeEnum implements ExceptionEnum {
    // 文章错误
    Article_NOT_EXIST(500100,"该文章不存在");


    CmsErrorCodeEnum(Integer code, String message) {
        this.code = code;
        this.message = message;
    }

    private Integer code;
    private String message;

    @Override
    public Integer getCode() {
        return code;
    }

    @Override
    public String getMessage() {
        return message;
    }
}

2. Result对象设计

/**
 * 通用返回result
 */
@Data
public class ZingResult<T> implements Serializable {

    private int code;
    private String msg;
    private T data;


    private ZingResult() {
        this.code = ResultMsgEnum.SUCCESS.getCode();
        this.msg = ResultMsgEnum.SUCCESS.getMessage();
    }

    private ZingResult(T data) {
        this.code = ResultMsgEnum.SUCCESS.getCode();
        this.msg = ResultMsgEnum.SUCCESS.getMessage();
        this.data = data;
    }


    private ZingResult(ExceptionEnum exceptionEnum) {
        this.code = exceptionEnum.getCode();
        this.msg = exceptionEnum.getMessage();
    }

    public static ZingResult success() {
        return new ZingResult();
    }

    public static <T> ZingResult<T> success(T data) {
        return new ZingResult<>(data);
    }

    public static <T> ZingResult<T> error(ExceptionEnum exceptionEnum) {
        return new ZingResult<>(exceptionEnum);
    }

}

3. 统一异常处理

3.1 异常父类

/**
 * 异常父类
 *
 * @author 王洪玉
 * @date 2018/11/11
 */

@Getter
public class ZingException extends RuntimeException {

    private Integer code;
    private String message;

    public ZingException(ExceptionEnum exceptionEnum){
        super(exceptionEnum.getMessage());
        this.code = exceptionEnum.getCode();
        this.message = exceptionEnum.getMessage();
    }
}

3.2 业务异常类

/**
 * 业务自定义异常类
 */
@Getter
public class BusinessException extends ZingException {
    private ExceptionEnum exceptionEnum;

    public BusinessException(ExceptionEnum exceptionEnum) {
        super(exceptionEnum);
        this.exceptionEnum = exceptionEnum;
    }
}

3.3 异常拦截处理

@Slf4j
@ResponseBody
@ControllerAdvice
public class GlobalExceptionHandler {


    /**
     * 拦截未知错误异常
     *
     * @param request 请求
     * @param e       未知异常
     * @return 通用返回格式
     */
    @ExceptionHandler(Exception.class)
    public ZingResult cmsException(HttpServletRequest request, Exception e) {
        log.error("请求的url为{}出现系统异常,异常信息为:", request.getRequestURI(), e);
        return ZingResult.error(ResultMsgEnum.ERROR);
    }


    /**
     * 拦截CMS业务异常
     *
     * @param request 请求
     * @param e       业务异常
     * @return 通用返回格式
     */
    @ExceptionHandler(CmsBusinessException.class)
    public ZingResult cmsBusinessException(HttpServletRequest request, CmsBusinessException e) {
        log.error("请求的url为{}出现业务异常,异常信息为:", request.getRequestURI(), e);
        return ZingResult.error(e.getExceptionEnum());
    }
}

4. 使用示例

if(CollectionUtils.isEmpty(articleList)){
    throw new CmsBusinessException(CmsErrorCodeEnum.ARTICLE_NOT_EXIST);
}