From 8ce227cce7d92ca7ac1e5e7b0e63b8b41da604a2 Mon Sep 17 00:00:00 2001 From: mherbaghinyan Date: Fri, 28 Dec 2018 16:26:57 +0400 Subject: [PATCH 1/3] 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 set = new HashSet<>(); + set.add("Canada"); + set.add("USA"); + + coreJDK(set); + guavaOf(); + copyOf(set); + setOf(); + } + + private static void setOf() { + Set immutable = Set.of("Canada", "USA"); + System.out.println(immutable); + } + + private static void guavaOf() { + Set immutable = ImmutableSet.of("Canada", "USA"); + System.out.println(immutable); + } + + private static void copyOf(Set set) { + Set immutable = ImmutableSet.copyOf(set); + set.add("Costa Rica"); + System.out.println(immutable); + } + + private static void coreJDK(Set set) { + Set unmodifiableSet = Collections.unmodifiableSet(set); + set.add("Costa Rica"); + System.out.println(unmodifiableSet); + } +} From fb8183d69434b3f3a4b3d2ec311cdbe6a40d98da Mon Sep 17 00:00:00 2001 From: mherbaghinyan Date: Fri, 28 Dec 2018 16:33:41 +0400 Subject: [PATCH 2/3] comment java 9 --- .../src/main/java/com/baeldung/set/UnmodifiableSet.java | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) 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 index d821c46a3c..06f477c50a 100644 --- a/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java +++ b/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java @@ -17,12 +17,12 @@ public class UnmodifiableSet { coreJDK(set); guavaOf(); copyOf(set); - setOf(); + java9Of(); } - private static void setOf() { - Set immutable = Set.of("Canada", "USA"); - System.out.println(immutable); + private static void java9Of() { + //Set immutable = Set.of("Canada", "USA"); + //System.out.println(immutable); } private static void guavaOf() { From a89983a65cbf165f0e18889b6e43b1a7ed686dd3 Mon Sep 17 00:00:00 2001 From: mherbaghinyan Date: Sun, 30 Dec 2018 14:19:24 +0400 Subject: [PATCH 3/3] move unmodifiable set code to java 9 module --- .../com/baeldung/java9}/set/UnmodifiableSet.java | 6 +++--- .../java/com/baeldung/java9/SetExamplesUnitTest.java | 12 ++++++++++++ 2 files changed, 15 insertions(+), 3 deletions(-) rename {core-java-collections/src/main/java/com/baeldung => core-java-9/src/main/java/com/baeldung/java9}/set/UnmodifiableSet.java (88%) diff --git a/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java b/core-java-9/src/main/java/com/baeldung/java9/set/UnmodifiableSet.java similarity index 88% rename from core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java rename to core-java-9/src/main/java/com/baeldung/java9/set/UnmodifiableSet.java index 06f477c50a..7dbcd2a3a3 100644 --- a/core-java-collections/src/main/java/com/baeldung/set/UnmodifiableSet.java +++ b/core-java-9/src/main/java/com/baeldung/java9/set/UnmodifiableSet.java @@ -1,4 +1,4 @@ -package com.baeldung.set; +package com.baeldung.java9.set; import com.google.common.collect.ImmutableSet; @@ -21,8 +21,8 @@ public class UnmodifiableSet { } private static void java9Of() { - //Set immutable = Set.of("Canada", "USA"); - //System.out.println(immutable); + Set immutable = Set.of("Canada", "USA"); + System.out.println(immutable); } private static void guavaOf() { diff --git a/core-java-9/src/test/java/com/baeldung/java9/SetExamplesUnitTest.java b/core-java-9/src/test/java/com/baeldung/java9/SetExamplesUnitTest.java index 9e7e8e6e4b..28e71affcc 100644 --- a/core-java-9/src/test/java/com/baeldung/java9/SetExamplesUnitTest.java +++ b/core-java-9/src/test/java/com/baeldung/java9/SetExamplesUnitTest.java @@ -1,5 +1,7 @@ package com.baeldung.java9; +import java.util.Collections; +import java.util.HashSet; import java.util.Set; import org.junit.Test; @@ -23,4 +25,14 @@ public class SetExamplesUnitTest { Set intSet = Set.of(intArray); assertEquals(intSet.size(), intArray.length); } + + @Test(expected = UnsupportedOperationException.class) + public void testUnmodifiableSet() { + Set set = new HashSet<>(); + set.add("Canada"); + set.add("USA"); + + Set unmodifiableSet = Collections.unmodifiableSet(set); + unmodifiableSet.add("Costa Rica"); + } }