From d2332a5c1096d0fcfd0c853c59cc58f5389ad4a5 Mon Sep 17 00:00:00 2001 From: Mayank Agarwal Date: Sat, 5 Feb 2022 11:52:40 +0530 Subject: [PATCH] BAEL-5351: Added empty map initialization methods in Java --- .../map/initialize/EmptyMapInitializer.java | 49 +++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/initialize/EmptyMapInitializer.java diff --git a/core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/initialize/EmptyMapInitializer.java b/core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/initialize/EmptyMapInitializer.java new file mode 100644 index 0000000000..bef6fa5374 --- /dev/null +++ b/core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/initialize/EmptyMapInitializer.java @@ -0,0 +1,49 @@ +package com.baeldung.map.initialize; + +import com.google.common.collect.ImmutableMap; +import com.google.common.collect.Maps; +import java.util.Collections; +import java.util.HashMap; +import java.util.LinkedHashMap; +import java.util.Map; +import java.util.NavigableMap; +import java.util.TreeMap; + +public class EmptyMapInitializer { + + public static Map articleMap; + static { + articleMap = new HashMap<>(); + } + + public static Map createEmptyMap() { + return Collections.emptyMap(); + } + + public void createMapUsingConstructors() { + Map hashMap = new HashMap(); + Map linkedHashMap = new LinkedHashMap(); + Map treeMap = new TreeMap(); + } + + public Map createEmptyMapUsingMapsObject() { + Map emptyMap = Maps.newHashMap(); + return emptyMap; + } + + public Map createGenericEmptyMapUsingMapsObject() { + return Maps.newHashMap(); + } + + public static Map createMapUsingGuava() { + Map emptyMapUsingGuava = + Maps.newHashMap(ImmutableMap.of()); + return emptyMapUsingGuava; + } + + public NavigableMap createEmptyNavigableMap() { + NavigableMap navigableMap = Collections.emptyNavigableMap(); + return navigableMap; + } + +}