public static String encode(String str) throws UnsupportedEncodingException, NoSuchAlgorithmException {
		// 确定计算方法
		MessageDigest md5 = MessageDigest.getInstance("MD5");
		BASE64Encoder base64Encoder = new BASE64Encoder();
		// 加密字符串
		String newstr = base64Encoder.encode(md5.digest(str.getBytes("utf-8")));
		return newstr;
	}

/**
 * 统一返回实体
 * @author maxu
 */
@Data
public class CommonReturnType {

	// 表明对应请求的处理结果 success 或者 fail
	private String status;
	// 如果 status = suceess 返回前端需要的请求信息
	// 如果 status = fail 返回通用的错误码格式
	private Object data;

	public static CommonReturnType create(Object result) {
		return  CommonReturnType.create(result,"success");
	}
	
	public static CommonReturnType create(Object result,String status) {
		CommonReturnType type = new CommonReturnType();
		type.setData(result);
		type.setStatus(status);
		return type;
	}
}

public class BaseController {
	@ExceptionHandler(Exception.class)
    // 重新设置code
	@ResponseStatus(HttpStatus.OK)
	@ResponseBody
	public Object handlerException(HttpServletRequest request, Exception ex) {

		Map responseData = new HashMap();
		if (ex instanceof BusinessException) {
			BusinessException businessException = (BusinessException) ex;
			responseData.put("errCode", businessException.getErrorCode());
			responseData.put("errMsg", businessException.getErrorMsg());
		} else {
			responseData.put("errCode", EmBusinessError.UNKNOWN_ERROR.getErrorCode());
			responseData.put("errMsg", EmBusinessError.UNKNOWN_ERROR.getErrorMsg());
		}
		return CommonReturnType.create(responseData, "fail");
	}

}

/**
 * @author maxu
 */
@Configuration
@EnableSwagger2
public class SwaggerConfig {
	@Bean
	public Docket createRestApi() {
		return new Docket(DocumentationType.SWAGGER_2)
				.apiInfo(apiInfo())
				.select()
				.apis(RequestHandlerSelectors.basePackage("com.miaoshaproject.controller"))
				.paths(PathSelectors.any())
				.build();
	}


	private ApiInfo apiInfo() {
		return new ApiInfoBuilder()
				.title("秒杀模块API")
				.description("更多文章请关注https://github.com/flymecode/miaosha")
				.termsOfServiceUrl("https://github.com/flymecode/miaosha")
				.version("V.1.1.0")
				.build();
	}

}

	public CommonReturnType createItem(@RequestParam(name = "title") String title,
	                                   @RequestParam(name = "description") String description,
	                                   @RequestParam(name = "price") BigDecimal price,
	                                   @RequestParam(name = "stock") Integer stock,
	                                   @RequestParam(name = "imgUrl") String imgUrl) throws BusinessException {

		ItemModel itemModel = new ItemModel();
		itemModel.setTitle(title);
		itemModel.setDescription(description);
		itemModel.setPrice(price);
		itemModel.setStock(stock);
		itemModel.setImgUrl(imgUrl);

		ItemModel itemForReuturn = itemService.createItem(itemModel);
		ItemVO itemVO = convertVOFromModel(itemForReuturn);
		return CommonReturnType.create(itemVO);
	}

// 定义一个异常的同意结口
public interface CommonError {
	int getErrorCode();

	String getErrorMsg();

	CommonError setErrorMsg(String errorMsg);

}

// 实现CommonError接口
public class BusinessException extends Exception implements CommonError {
	
	private CommonError commonError;

	//直接接受
	public BusinessException(CommonError commonError) {
		super();
		this.commonError = commonError;
	}

	public BusinessException(CommonError commonError,String errMsg) {
		super();
		this.commonError.setErrorMsg(errMsg);
		this.commonError = commonError;
	}
	@Override
	public int getErrorCode() {
		return commonError.getErrorCode();
	}

	@Override
	public String getErrorMsg() {
		return commonError.getErrorMsg();
	}

	@Override
	public CommonError setErrorMsg(String errorMsg) {
		this.commonError.setErrorMsg(errorMsg);
		return this;
	}
}

// 错误类型定义
public enum EmBusinessError implements CommonError {
	// 通用错误类型0001
	PARAMETER_VALDITION_ERROR(00001,"参数不合法"),
        // 1000x开头定义用户相关信息
	USER_NOT_EXSIT(10001,"用户不存在"),
	UNKNOWN_ERROR(20000,"未知错误"),
	STOCK_NOT_ENOUGH(30001,"库存不足"),
	USER_LOGIN_FAIL(20001,"用户或密码不正确"),
	USER_NOT_LOGIN(20002,"用户未登录") ;
	private int errorCode;
	private String errorMsg;

	EmBusinessError(int errorCode, String errorMsg) {
		this.errorCode = errorCode;
		this.errorMsg = errorMsg;
	}

	@Override
	public int getErrorCode() {
		return this.errorCode;
	}

	@Override
	public String getErrorMsg() {
		return this.errorMsg;
	}

	@Override
	public CommonError setErrorMsg(String errorMsg) {
		this.errorMsg = errorMsg;
		return this;
	}
}