diff --git a/DesignPattern/DesignPattern.sln b/DesignPattern/DesignPattern.sln
new file mode 100644
index 0000000..8c8f448
--- /dev/null
+++ b/DesignPattern/DesignPattern.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.32630.194
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Singleton", "Singleton\Singleton.csproj", "{37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}"
+EndProject
+Global
+ GlobalSection(SolutionConfigurationPlatforms) = preSolution
+ Debug|Any CPU = Debug|Any CPU
+ Release|Any CPU = Release|Any CPU
+ EndGlobalSection
+ GlobalSection(ProjectConfigurationPlatforms) = postSolution
+ {37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+ {37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}.Debug|Any CPU.Build.0 = Debug|Any CPU
+ {37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}.Release|Any CPU.ActiveCfg = Release|Any CPU
+ {37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}.Release|Any CPU.Build.0 = Release|Any CPU
+ EndGlobalSection
+ GlobalSection(SolutionProperties) = preSolution
+ HideSolutionNode = FALSE
+ EndGlobalSection
+ GlobalSection(ExtensibilityGlobals) = postSolution
+ SolutionGuid = {F3BACC7E-F135-42F5-B308-757DA855C6F6}
+ EndGlobalSection
+EndGlobal
diff --git a/DesignPattern/DesignPattern/App.config b/DesignPattern/DesignPattern/App.config
new file mode 100644
index 0000000..193aecc
--- /dev/null
+++ b/DesignPattern/DesignPattern/App.config
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/DesignPattern/DesignPattern/DesignPattern.csproj b/DesignPattern/DesignPattern/DesignPattern.csproj
new file mode 100644
index 0000000..eeffd3f
--- /dev/null
+++ b/DesignPattern/DesignPattern/DesignPattern.csproj
@@ -0,0 +1,53 @@
+
+
+
+
+ Debug
+ AnyCPU
+ {0AFC8AB1-896C-4686-A5EA-58DE7A3CB612}
+ Exe
+ DesignPattern
+ DesignPattern
+ v4.8
+ 512
+ true
+ true
+
+
+ AnyCPU
+ true
+ full
+ false
+ bin\Debug\
+ DEBUG;TRACE
+ prompt
+ 4
+
+
+ AnyCPU
+ pdbonly
+ true
+ bin\Release\
+ TRACE
+ prompt
+ 4
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/DesignPattern/DesignPattern/Program.cs b/DesignPattern/DesignPattern/Program.cs
new file mode 100644
index 0000000..0c6fd1a
--- /dev/null
+++ b/DesignPattern/DesignPattern/Program.cs
@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DesignPattern
+{
+ class Program
+ {
+ static void Main(string[] args)
+ {
+ }
+ }
+}
diff --git a/DesignPattern/DesignPattern/Properties/AssemblyInfo.cs b/DesignPattern/DesignPattern/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..0ffce32
--- /dev/null
+++ b/DesignPattern/DesignPattern/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// 어셈블리에 대한 일반 정보는 다음 특성 집합을 통해
+// 제어됩니다. 어셈블리와 관련된 정보를 수정하려면
+// 이러한 특성 값을 변경하세요.
+[assembly: AssemblyTitle("DesignPattern")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("DesignPattern")]
+[assembly: AssemblyCopyright("Copyright © 2022")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// ComVisible을 false로 설정하면 이 어셈블리의 형식이 COM 구성 요소에
+// 표시되지 않습니다. COM에서 이 어셈블리의 형식에 액세스하려면
+// 해당 형식에 대해 ComVisible 특성을 true로 설정하세요.
+[assembly: ComVisible(false)]
+
+// 이 프로젝트가 COM에 노출되는 경우 다음 GUID는 typelib의 ID를 나타냅니다.
+[assembly: Guid("0afc8ab1-896c-4686-a5ea-58de7a3cb612")]
+
+// 어셈블리의 버전 정보는 다음 네 가지 값으로 구성됩니다.
+//
+// 주 버전
+// 부 버전
+// 빌드 번호
+// 수정 버전
+//
+// 모든 값을 지정하거나 아래와 같이 '*'를 사용하여 빌드 번호 및 수정 번호를
+// 기본값으로 할 수 있습니다.
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/DesignPattern/Singleton/App.config b/DesignPattern/Singleton/App.config
new file mode 100644
index 0000000..193aecc
--- /dev/null
+++ b/DesignPattern/Singleton/App.config
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/DesignPattern/Singleton/Client.cs b/DesignPattern/Singleton/Client.cs
new file mode 100644
index 0000000..3bdc905
--- /dev/null
+++ b/DesignPattern/Singleton/Client.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton
+{
+ class Client
+ {
+ public static void HowToTest()
+ {
+ var username = Configuration.Settings["username"];
+ var server = Configuration.Settings["server"];
+
+ Console.WriteLine($"server: {server}");
+ Console.WriteLine($"username: {username}");
+ }
+ }
+}
diff --git a/DesignPattern/Singleton/Configuration.cs b/DesignPattern/Singleton/Configuration.cs
new file mode 100644
index 0000000..cf741f9
--- /dev/null
+++ b/DesignPattern/Singleton/Configuration.cs
@@ -0,0 +1,35 @@
+using Newtonsoft.Json.Linq;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton
+{
+ public sealed class Configuration
+ {
+ public static Configuration Settings { get; } = new Configuration();
+
+ private Dictionary dict = new Dictionary();
+
+ private Configuration()
+ {
+ LoadConfig();
+ }
+
+ private void LoadConfig()
+ {
+ string str = File.ReadAllText("config.json");
+ JObject jo = JObject.Parse(str);
+
+ foreach (KeyValuePair kv in jo)
+ {
+ dict.Add(kv.Key, kv.Value);
+ }
+ }
+
+ public object this[string key] { get { return dict[key]; } }
+ }
+}
diff --git a/DesignPattern/Singleton/Program.cs b/DesignPattern/Singleton/Program.cs
new file mode 100644
index 0000000..20fdd43
--- /dev/null
+++ b/DesignPattern/Singleton/Program.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton
+{
+ class Program
+ {
+ static void Main(string[] args)
+ {
+ Client.HowToTest();
+
+ Console.ReadKey();
+ }
+ }
+}
diff --git a/DesignPattern/Singleton/Properties/AssemblyInfo.cs b/DesignPattern/Singleton/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..847e302
--- /dev/null
+++ b/DesignPattern/Singleton/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// 어셈블리에 대한 일반 정보는 다음 특성 집합을 통해
+// 제어됩니다. 어셈블리와 관련된 정보를 수정하려면
+// 이러한 특성 값을 변경하세요.
+[assembly: AssemblyTitle("Singleton")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("Singleton")]
+[assembly: AssemblyCopyright("Copyright © 2022")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// ComVisible을 false로 설정하면 이 어셈블리의 형식이 COM 구성 요소에
+// 표시되지 않습니다. COM에서 이 어셈블리의 형식에 액세스하려면
+// 해당 형식에 대해 ComVisible 특성을 true로 설정하세요.
+[assembly: ComVisible(false)]
+
+// 이 프로젝트가 COM에 노출되는 경우 다음 GUID는 typelib의 ID를 나타냅니다.
+[assembly: Guid("37fe4d0c-a213-4ea5-b3ef-db2db3971ace")]
+
+// 어셈블리의 버전 정보는 다음 네 가지 값으로 구성됩니다.
+//
+// 주 버전
+// 부 버전
+// 빌드 번호
+// 수정 버전
+//
+// 모든 값을 지정하거나 아래와 같이 '*'를 사용하여 빌드 번호 및 수정 번호를
+// 기본값으로 할 수 있습니다.
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/DesignPattern/Singleton/Singleton.csproj b/DesignPattern/Singleton/Singleton.csproj
new file mode 100644
index 0000000..8a68e5a
--- /dev/null
+++ b/DesignPattern/Singleton/Singleton.csproj
@@ -0,0 +1,59 @@
+
+
+
+
+ Debug
+ AnyCPU
+ {37FE4D0C-A213-4EA5-B3EF-DB2DB3971ACE}
+ Exe
+ Singleton
+ Singleton
+ v4.8
+ 512
+ true
+ true
+
+
+ AnyCPU
+ true
+ full
+ false
+ bin\Debug\
+ DEBUG;TRACE
+ prompt
+ 4
+
+
+ AnyCPU
+ pdbonly
+ true
+ bin\Release\
+ TRACE
+ prompt
+ 4
+
+
+
+ ..\packages\Newtonsoft.Json.13.0.1\lib\net45\Newtonsoft.Json.dll
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/DesignPattern/Singleton/packages.config b/DesignPattern/Singleton/packages.config
new file mode 100644
index 0000000..bc2a97e
--- /dev/null
+++ b/DesignPattern/Singleton/packages.config
@@ -0,0 +1,4 @@
+
+
+
+
\ No newline at end of file