diff --git a/gson/build.gradle.kts b/gson/build.gradle.kts
new file mode 100644
index 0000000..37021ac
--- /dev/null
+++ b/gson/build.gradle.kts
@@ -0,0 +1,16 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+plugins {
+    id("elex-java")
+}
+
+dependencies {
+// https://mvnrepository.com/artifact/com.google.code.gson/gson
+    implementation("com.google.code.gson:gson:2.10.1")
+
+}
diff --git a/gson/logback.xml b/gson/logback.xml
new file mode 100644
index 0000000..74ff8a3
--- /dev/null
+++ b/gson/logback.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Examples for Java
+  ~
+  ~ Copyright (c) 2021. Elex. All Rights Reserved.
+  ~ https://www.elex-project.com/
+  -->
+
+<configuration>
+
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="TRACE">
+		<appender-ref ref="CONSOLE" />
+	</root>
+</configuration>
diff --git a/gson/src/main/java/kr/pe/elex/examples/GsonSample.java b/gson/src/main/java/kr/pe/elex/examples/GsonSample.java
new file mode 100644
index 0000000..55ceded
--- /dev/null
+++ b/gson/src/main/java/kr/pe/elex/examples/GsonSample.java
@@ -0,0 +1,32 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import com.elex_project.abraxas.Console;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class GsonSample {
+
+	public static void main(String... args){
+		Gson gson = new GsonBuilder().create();
+
+		// to json
+		Person charlie = new Person("Charlie", 13);
+		String json = gson.toJson(charlie);
+		Console.writeLine(json);
+
+		// from json
+		Person steve = gson.fromJson("{'name':'Steve', 'age':43}", Person.class);
+		Console.writeLine(steve);
+	}
+
+
+}
diff --git a/gson/src/main/java/kr/pe/elex/examples/Person.java b/gson/src/main/java/kr/pe/elex/examples/Person.java
new file mode 100644
index 0000000..86ac3fe
--- /dev/null
+++ b/gson/src/main/java/kr/pe/elex/examples/Person.java
@@ -0,0 +1,22 @@
+/*
+ * Examples for Java
+ *
+ * Copyright (c) 2023. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.ToString;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@ToString
+public class Person {
+	private String name;
+	private int age;
+}
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 3d6fbb0..07afe4f 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -15,5 +15,5 @@ include(
     "xml", "jackson", "jsoup", "markdown", "network", "httpd",
     "properties", "serial-io",
     "mustache", "thymeleaf", "locale", "quartz", "sysinfo",
-    "imaging", "stream", "sound", "midi"
+    "imaging", "stream", "sound", "midi", "gson"
 )
diff --git a/stream/src/main/java/kr/pe/elex/examples/Sample.java b/stream/src/main/java/kr/pe/elex/examples/Sample.java
index 8a60fd7..6f7a8e9 100644
--- a/stream/src/main/java/kr/pe/elex/examples/Sample.java
+++ b/stream/src/main/java/kr/pe/elex/examples/Sample.java
@@ -19,8 +19,11 @@ public class Sample {
 	}
 
 
-	public Stream<String> toStream(List<String> list) {
-		return null == list ? Stream.empty() : list.stream();
+	/*
+	list to stream
+	 */
+	public Stream<String> toStream(final List<String> list) {
+		return (null == list || list.isEmpty()) ? Stream.empty() : list.stream();
 	}