--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/paper/src/java-interface-implements.java	Tue Feb 02 14:17:05 2021 +0900
@@ -0,0 +1,17 @@
+// interface
+interface Animal {
+  public void animalSound(); // interface method (does not have a body)
+  public void sleep(); // interface method (does not have a body)
+}
+
+// Pig "implements" the Animal interface
+class Pig implements Animal {
+  public void animalSound() {
+    // The body of animalSound() is provided here
+    System.out.println("The pig says: wee wee");
+  }
+  public void sleep() {
+    // The body of sleep() is provided here
+    System.out.println("Zzz");
+  }
+}
\ No newline at end of file