From 8ce227cce7d92ca7ac1e5e7b0e63b8b41da604a2 Mon Sep 17 00:00:00 2001
From: mherbaghinyan <mbaghinyan@gmail.com>
Date: Fri, 28 Dec 2018 16:26:57 +0400
Subject: [PATCH] immutable sets

---
 .../com/baeldung/set/UnmodifiableSet.java     | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java

diff --git a/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java b/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java
new file mode 100644
index 0000000000..d821c46a3c
--- /dev/null
+++ b/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java
@@ -0,0 +1,44 @@
+package com.baeldung.set;
+
+import com.google.common.collect.ImmutableSet;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+public class UnmodifiableSet {
+
+    public static void main(String[] args) {
+
+        Set<String> set = new HashSet<>();
+        set.add("Canada");
+        set.add("USA");
+
+        coreJDK(set);
+        guavaOf();
+        copyOf(set);
+        setOf();
+    }
+
+    private static void setOf() {
+        Set<String> immutable = Set.of("Canada", "USA");
+        System.out.println(immutable);
+    }
+
+    private static void guavaOf() {
+        Set<String> immutable = ImmutableSet.of("Canada", "USA");
+        System.out.println(immutable);
+    }
+
+    private static void copyOf(Set<String> set) {
+        Set<String> immutable = ImmutableSet.copyOf(set);
+        set.add("Costa Rica");
+        System.out.println(immutable);
+    }
+
+    private static void coreJDK(Set<String> set) {
+        Set<String> unmodifiableSet = Collections.unmodifiableSet(set);
+        set.add("Costa Rica");
+        System.out.println(unmodifiableSet);
+    }
+}