JAVA-11382 Update article Create an empty map in Java (eugenp#12383)

anuragkumawat · web-flow · commit 95d381a8a642 · 2022-06-20T18:46:31.000+05:30
diff --git a/core-java-modules/core-java-collections-4/src/main/java/com/baeldung/maps/initialize/EmptyMapInitializer.java b/core-java-modules/core-java-collections-4/src/main/java/com/baeldung/maps/initialize/EmptyMapInitializer.java
@@ -32,7 +32,7 @@ public Map<String, String> createEmptyMapUsingMapsObject() {
     return emptyMap;
   }
 
-  public Map createGenericEmptyMapUsingMapsObject() {
+  public Map createGenericEmptyMapUsingGuavaMapsObject() {
     Map genericEmptyMap = Maps.<String, Integer>newHashMap();
     return genericEmptyMap;
   }
@@ -43,6 +43,11 @@ public static Map<String, String> createMapUsingGuava() {
     return emptyMapUsingGuava;
   }
 
+  public static Map<String, String> createImmutableMapUsingGuava() {
+	    Map<String, String> emptyImmutableMapUsingGuava = ImmutableMap.of();
+	    return emptyImmutableMapUsingGuava;
+  }
+  
   public SortedMap<String, String> createEmptySortedMap() {
     SortedMap<String, String> sortedMap = Collections.emptySortedMap();
     return sortedMap;
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/maps/initialize/EmptyMapInitializerUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/maps/initialize/EmptyMapInitializerUnitTest.java
@@ -28,4 +28,9 @@ public void givenEmptyMap_whenCreatedUsingGuava_returnsEmptyOrNot() {
     assertFalse(emptyMapUsingGuava.isEmpty());
   }
 
+  @Test(expected=UnsupportedOperationException.class)
+  public void givenImmutableEmptyMapUsingGuava_whenAddingEntries_throwsException() {
+    Map<String, String> map = EmptyMapInitializer.createImmutableMapUsingGuava();
+    map.put("key", "value");
+  }
 }

Original file line number	Diff line number	Diff line change
`@@ -32,7 +32,7 @@ public Map<String, String> createEmptyMapUsingMapsObject() {`
`32`	`32`	`return emptyMap;`
`33`	`33`	`}`
`34`	`34`
`35`		`- public Map createGenericEmptyMapUsingMapsObject() {`
	`35`	`+ public Map createGenericEmptyMapUsingGuavaMapsObject() {`
`36`	`36`	`Map genericEmptyMap = Maps.<String, Integer>newHashMap();`
`37`	`37`	`return genericEmptyMap;`
`38`	`38`	`}`
`@@ -43,6 +43,11 @@ public static Map<String, String> createMapUsingGuava() {`
`43`	`43`	`return emptyMapUsingGuava;`
`44`	`44`	`}`
`45`	`45`
	`46`	`+ public static Map<String, String> createImmutableMapUsingGuava() {`
	`47`	`+ Map<String, String> emptyImmutableMapUsingGuava = ImmutableMap.of();`
	`48`	`+ return emptyImmutableMapUsingGuava;`
	`49`	`+ }`
	`50`	`+`
`46`	`51`	`public SortedMap<String, String> createEmptySortedMap() {`
`47`	`52`	`SortedMap<String, String> sortedMap = Collections.emptySortedMap();`
`48`	`53`	`return sortedMap;`
Original file line number	Diff line number	Diff line change
`@@ -28,4 +28,9 @@ public void givenEmptyMap_whenCreatedUsingGuava_returnsEmptyOrNot() {`
`28`	`28`	`assertFalse(emptyMapUsingGuava.isEmpty());`
`29`	`29`	`}`
`30`	`30`
	`31`	`+ @Test(expected=UnsupportedOperationException.class)`
	`32`	`+ public void givenImmutableEmptyMapUsingGuava_whenAddingEntries_throwsException() {`
	`33`	`+ Map<String, String> map = EmptyMapInitializer.createImmutableMapUsingGuava();`
	`34`	`+ map.put("key", "value");`
	`35`	`+ }`
`31`	`36`	`}`