C# 实体原则的重构
在阅读了一本书和一篇在线文章中有关SOLID代码的内容后,我想重构一个现有的类,使其能够“SOLID”兼容 但我想我迷路了,尤其是在依赖项注入方面:当我想实例化类的一个对象时,我需要“注入”所有依赖项,但依赖项本身有依赖项。。这就是我开始迷路的地方 想法是这样的:我想创建一个类(在我的例子中,是一个简单的AmazonS3包装类)来di简单的上传和获取URL操作 如何正确使用接口和依赖项注入?出了什么问题? 这个班应该是什么样子 这是我的密码:C# 实体原则的重构,c#,solid-principles,C#,Solid Principles,在阅读了一本书和一篇在线文章中有关SOLID代码的内容后,我想重构一个现有的类,使其能够“SOLID”兼容 但我想我迷路了,尤其是在依赖项注入方面:当我想实例化类的一个对象时,我需要“注入”所有依赖项,但依赖项本身有依赖项。。这就是我开始迷路的地方 想法是这样的:我想创建一个类(在我的例子中,是一个简单的AmazonS3包装类)来di简单的上传和获取URL操作 如何正确使用接口和依赖项注入?出了什么问题? 这个班应该是什么样子 这是我的密码: public interface IConfigur
public interface IConfigurationProvider
{
string GetConfigurationValue(String configurationKey);
}
public interface ILogger
{
void WriteLog(String message);
}
public interface IAWSClientProvider
{
AmazonS3Client GetAmazonS3Client();
}
public interface IAWSBucketManager
{
string GetDefaultBucketName();
}
public class AWSBucketManager : IAWSBucketManager
{
ILogger logger;
IConfigurationProvider configurationProvider;
public AWSBucketManager(ILogger Logger, IConfigurationProvider ConfigurationProvider)
{
logger = Logger;
configurationProvider = ConfigurationProvider;
}
public string GetDefaultBucketName()
{
string bucketName = string.Empty;
try
{
bucketName = configurationProvider.GetConfigurationValue("Amazon_S3_ExportAds_BucketName");
}
catch (Exception ex)
{
logger.WriteLog(String.Format("getBucketName : Unable to get bucket name from configuration.\r\n{0}", ex));
}
return bucketName;
}
}
public class AWSClientProvider : IAWSClientProvider
{
IConfigurationProvider configurationProvider;
IAWSBucketManager awsBucketManager;
ILogger logger;
private string awsS3BucketName;
private Dictionary<string, RegionEndpoint> regionEndpoints;
public AWSClientProvider(IConfigurationProvider ConfigurationProvider, IAWSBucketManager BucketManager, ILogger Logger)
{
logger = Logger;
configurationProvider = ConfigurationProvider;
awsBucketManager = BucketManager;
}
private RegionEndpoint getAWSRegion()
{
RegionEndpoint regionEndpoint = null;
// Init endpoints dictionary
try
{
IEnumerable<RegionEndpoint> regions = RegionEndpoint.EnumerableAllRegions;
regionEndpoints = regions.ToDictionary(r => r.SystemName, r => r);
}
catch (Exception Ex)
{
logger.WriteLog(String.Format("getAWSRegion() - Failed to get region list from AWS.\r\n{0}", Ex));
throw;
}
// Get configuration value
try
{
string Config = configurationProvider.GetConfigurationValue("Amazon_S3_Region");
if (String.IsNullOrEmpty(Config))
{
throw new Exception("getAWSRegion() : Amazon_S3_Region must not be null or empty string.");
}
regionEndpoint = regionEndpoints[Config];
}
catch (Exception Ex)
{
logger.WriteLog(String.Format("getAWSRegion() : Unable to get region settings from configuration.\r\n{0}", Ex));
throw Ex;
}
return regionEndpoint;
}
private AWSCredentials getAWSCredentials()
{
string accessKey, secretKey;
BasicAWSCredentials awsCredentials;
try
{
accessKey = configurationProvider.GetConfigurationValue("Amazon_S3_AccessKey");
secretKey = configurationProvider.GetConfigurationValue("Amazon_S3_SecretKey");
}
catch (Exception Ex)
{
logger.WriteLog(String.Format("getAWSCredentials() - Unable to get access key and secrey key values from configuration.\r\n", Ex.Message));
throw;
}
try
{
awsCredentials = new BasicAWSCredentials(accessKey, secretKey);
}
catch (Exception Ex)
{
logger.WriteLog(String.Format("getAWSCredentials() - Unable to create basic AWS credentials object.\r\n{0}", Ex.Message));
awsCredentials = null;
throw;
}
return awsCredentials;
}
public AmazonS3Client GetAmazonS3Client()
{
AmazonS3Client client = null;
RegionEndpoint region = getAWSRegion();
AWSCredentials credentials = getAWSCredentials();
awsS3BucketName = awsBucketManager.GetDefaultBucketName();
if (credentials != null)
{
client = new AmazonS3Client(credentials, region);
}
return client;
}
}
public class AWSS3Actions
{
IConfigurationProvider configurationProvider; // decoupling getting configuration
ILogger logger; // decoupling logger
IAWSClientProvider awsClientProvider;
private const int defaultExpirationDays = 14;
public AWSS3Actions(IConfigurationProvider ConfigurationProvider, ILogger Logger, IAWSClientProvider ClientProvider)
{
configurationProvider = ConfigurationProvider;
logger = Logger;
awsClientProvider = ClientProvider;
}
#region Private Mmethods
private string getFileUrl(string fileName, int expirationDaysPeriod, string awsS3BucketName)
{
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest();
string URL = "";
DateTime dtBase = new DateTime();
dtBase = DateTime.Now;
dtBase = dtBase.AddDays(expirationDaysPeriod);
request.BucketName = awsS3BucketName;
request.Key = fileName;
request.Expires = dtBase;
try
{
URL = awsClientProvider.GetAmazonS3Client().GetPreSignedURL(request);
}
catch (AmazonS3Exception ex)
{
// log
logger.WriteLog(String.Format("getFileUrl() : Could not get presigned URL for the provided request.\r\n{0}", ex));
throw ex;
}
return URL;
}
private int getDefaultURLExpiration()
{
int expirationDays = 0;
try
{
// set the time span in days
int.TryParse(configurationProvider.GetConfigurationValue("getDefaultURLExpiration() : Amazon_S3_ExportAds_ExpirationDaysOfURL"), out expirationDays); // get from configuration util
}
catch
{
// in case of exception, set the min 14 days time space exiration
expirationDays = defaultExpirationDays;
}
return expirationDays;
}
private void validateUpload(string fileName, Stream fileStream)
{
if (fileName == null || fileName.Equals(string.Empty) || fileStream.Length < 1)
{
throw new Exception("fileName : File name must not be an empty string.");
}
if (fileStream == null)
{
throw new Exception("fileStream : Input memory stream (file stream) must not be null.");
}
}
#endregion
#region Public methods
public bool IsFileExists(string fileName, string awsS3BucketName)
{
bool fileExists = false;
try
{
S3FileInfo fileInfo = new S3FileInfo(awsClientProvider.GetAmazonS3Client(), awsS3BucketName, fileName);
fileExists = fileInfo.Exists;
}
catch (AmazonS3Exception Ex)
{
// log
logger.WriteLog(String.Format("isFileExists() : Could not determine if file (key) exists in S3 Bucket.\r\n", Ex.Message));
throw;
}
return fileExists;
}
public bool UploadObject(string fileName, Stream fileStream, string awsS3BucketName)
{
bool uploadResult = true;
// Validate input parameters
validateUpload(fileName, fileStream);
if (awsClientProvider.GetAmazonS3Client() != null)
{
try
{
PutObjectRequest request = new PutObjectRequest
{
BucketName = awsS3BucketName,
Key = fileName,
InputStream = fileStream
};
PutObjectResponse response = awsClientProvider.GetAmazonS3Client().PutObject(request);
if (response != null)
{
if (response.HttpStatusCode != System.Net.HttpStatusCode.OK)
{
var meta = response.ResponseMetadata.Metadata.Keys.
Select(k => k.ToString() + " : " + response.ResponseMetadata.Metadata[k]).
ToList().Aggregate((current, next) => current + "\r\n" + next);
// log error
logger.WriteLog(String.Format("Status Code: {0}\r\nETag : {1}\r\nResponse metadata : {1}",
(int)response.HttpStatusCode, response.ETag, meta));
// set the return value
uploadResult = false;
}
}
}
catch (AmazonS3Exception ex)
{
uploadResult = false;
if (ex.ErrorCode != null && (ex.ErrorCode.Equals("InvalidAccessKeyId") || ex.ErrorCode.Equals("InvalidSecurity")))
{
// LOG
logger.WriteLog(String.Format("UploadObject() : invalied credentials"));
throw ex;
}
else
{
// LOG
logger.WriteLog(String.Format("UploadObject() : Error occurred. Message:'{0}' when writing an object", ex.Message));
throw ex;
}
}
}
else
{
throw new Exception("UploadObject() : Could not start object upload because Amazon client is null.");
}
return uploadResult;
}
public bool UploadObject(string subFolderInBucket, string FileName, Stream fileStream, string awsS3BucketName)
{
return UploadObject(subFolderInBucket + @"/" + FileName, fileStream, awsS3BucketName);
}
public string GetURL(string fileName, string bucket)
{
string url = string.Empty;
try
{
if (IsFileExists(fileName, bucket))
{
url = getFileUrl(fileName, getDefaultURLExpiration(), bucket);
}
}
catch (Exception Ex)
{
// log
logger.WriteLog(String.Format("getURL : Failed in isFileExists() method. \r\n{0}", Ex.Message));
}
return url;
}
#endregion
}
公共接口IConfigurationProvider
{
string GetConfigurationValue(string configurationKey);
}
公共接口ILogger
{
无效写日志(字符串消息);
}
公共接口IAWSClientProvider
{
AmazonS3Client GetAmazonS3Client();
}
公共接口IAWSBucketManager
{
字符串GetDefaultBucketName();
}
公共类AWSBucketManager:IAWSBucketManager
{
ILogger记录器;
IConfigurationProvider配置提供程序;
公用AWSBucketManager(ILogger记录器、IConfigurationProvider配置提供程序)
{
记录器=记录器;
configurationProvider=configurationProvider;
}
公共字符串GetDefaultBucketName()
{
string bucketName=string.Empty;
尝试
{
bucketName=configurationProvider.GetConfigurationValue(“Amazon_S3_ExportAds_bucketName”);
}
捕获(例外情况除外)
{
logger.WriteLog(String.Format(“getBucketName:无法从配置中获取存储桶名称。\r\n{0}”,ex));
}
返回bucketName;
}
}
公共类AWSClientProvider:IAWSClientProvider
{
IConfigurationProvider配置提供程序;
IAWSBucketManager awsBucketManager;
ILogger记录器;
私有字符串awsS3BucketName;
专用字典区域点;
公共AWSClientProvider(IConfigurationProvider配置提供程序、IAWSBucketManager BucketManager、ILogger记录器)
{
记录器=记录器;
configurationProvider=configurationProvider;
awsBucketManager=BucketManager;
}
私有区域点getAWSRegion()
{
RegionEndpoint RegionEndpoint=null;
//初始化端点字典
尝试
{
IEnumerable regions=RegionEndpoint.EnumerableAllRegions;
regionEndpoints=regions.ToDictionary(r=>r.SystemName,r=>r);
}
捕获(例外情况除外)
{
logger.WriteLog(String.Format(“getAWSRegion()-无法从AWS获取区域列表。\r\n{0}”,Ex));
投掷;
}
//获取配置值
尝试
{
string Config=configurationProvider.GetConfigurationValue(“亚马逊地区”);
if(String.IsNullOrEmpty(Config))
{
抛出新异常(“getAWSRegion():Amazon_S3_区域不能为null或空字符串”);
}
regionEndpoint=regionEndpoints[Config];
}
捕获(例外情况除外)
{
logger.WriteLog(String.Format(“getAWSRegion():无法从配置中获取区域设置。\r\n{0}”,Ex));
掷骰子;
}
返回区域点;
}
私有AWSCredentials getAWSCredentials()
{
字符串accessKey,secretKey;
基本要求;
尝试
{
accessKey=configurationProvider.GetConfigurationValue(“Amazon_S3_accessKey”);
secretKey=configurationProvider.GetConfigurationValue(“Amazon_S3_secretKey”);
}
捕获(例外情况除外)
{
logger.WriteLog(String.Format(“getAWSCredentials()-无法从配置中获取访问密钥和secrey密钥值。\r\n”,Ex.Message));
投掷;
}
尝试
{
awsCredentials=新的基本凭证(accessKey、secretKey);
}
捕获(例外情况除外)
{
logger.WriteLog(String.Format(“getAWSCredentials()-无法创建基本AWS凭据对象。\r\n{0}”,Ex.Message));
awsCredentials=null;
投掷;
}
返回awsCredentials;
}
公共AmazonS3Client GetAmazonS3Client()
{
AmazonS3Client客户端=null;
RegionEndpoint region=getAWSRegion();
AWSCredentials凭据=getAWSCredentials();
awsS3BucketName=awsBucketManager.GetDefaultBucketName();
如果(凭据!=null)
{
客户端=新的AmazonS3Client(凭据,地区);
}
返回客户;
}
}
公共类AWSS3动作
{
IConfigurationProvider configurationProvider;//正在获取配置
ILogger记录器;//解耦记录器
IAWSClientProvider awsClientProvider;
private const int defaultExpirationDays=14;
公共AWSS3操作(IConfigurationProvider配置提供程序、ILogger记录器、IAWSClientProvider客户端提供程序)
{
configurationProvider=configurationProvider;
记录器=记录器;
awsClientProvider=ClientProvider;
}
#区域私有方法
私有字符串getFileUrl(字符串文件名,int expirationDaysPeriod,字符串awsS3BucketName)
{
GetPreSignedUrlRequest请求=新建GetPreSignedUrlRequest();
字符串URL=“”;
DateTime dtBase=新的日期时间();
dtBase=DateTime.Now;
dtBase=dtBase.AddDays(expirationDaysPeriod);
request.BucketName=awsS3BucketName;
request.Key=文件名;
request.Expires=dtBase;
尝试
{
URL=awsClientProvider.GetAmazonS3Client().GetPreSignedURL(请求);
}
捕获(AmazonS3Exception ex)
{
//日志
logger.WriteLog(字符串)。