diff --git a/Java/ActionListener.java b/Java/ActionListener.java
new file mode 100644
index 00000000..2bd455b7
--- /dev/null
+++ b/Java/ActionListener.java
@@ -0,0 +1,23 @@
+import java.awt.GridLayout;
+import javax.swing.JCheckBox;
+import javax.swing.JFrame;
+
+public class ActionListener {
+
+	public static void main(String[] args) {
+
+		// JFrame : initialize a window
+		JFrame f = new JFrame("Peekaboo Machine for My Son"); 
+
+		// JCheckBox
+		JCheckBox checkBox1 = new JCheckBox("Peakaboo!");
+		checkBox1.setHorizontalAlignment(JCheckBox.CENTER);
+		f.add(checkBox1);
+		
+		f.setSize(300, 600);
+		f.setLayout(new GridLayout(1, 2));
+		f.setVisible(true);
+		
+	}
+
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index 1988faaa..194990e0 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,12 @@ making a dashboard for managing Gitgub contributions by using `Github API`
 - Class_Test.py (2018.02.07)
 - Nirvana.py (2017.05.15)
 
+## My Java Practice
+- ActionListener.java (2021.04.22)
+- MyThread.java (2021.04.13)
+- Swing.java (2021.04.06)
+- MyDate.java (2021.03.08)
+
 ## My C# Practice
 - GCD.cs (2021.03.30)
 - TerminalGUI.cs (2021.03.24)
@@ -44,20 +50,11 @@ making a dashboard for managing Gitgub contributions by using `Github API`
 - Colorful Show (2020.03.04)
 - Ganzi.html (2017.04.03)
 
-## My Java Practice
-- Swing.java (2021.04.06)
-- MyDate.java (2021.03.08)
-
 ## My VBA Practice
 - Sigma2 (2021.01.03)
 - Sigma (2021.01.02)
 - Color_Scroll.bas (2020.11.14)
 
-## My Java Practice
-- MyThread.java (2021.04.13)
-- Swing.java (2021.04.06)
-- MyDate.java (2021.03.08)
-
 ## My QBasic Practice
 - Play Music (2021.02.20)
 - Hello World (2020.02.27)
\ No newline at end of file