BAEL-3926 - Java Map with case-insensitive keys

core-java-modules/core-java-collections-maps/pom.xml

@@ -26,10 +26,17 @@
             <version>${assertj.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-core</artifactId>
+            <version>${spring.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <properties>
         <commons-collections4.version>4.1</commons-collections4.version>
         <assertj.version>3.6.1</assertj.version>
+        <spring.version>5.2.5.RELEASE</spring.version>
     </properties>
 </project>

java-collections-maps/src/test/java/com/baeldung/map/CaseInsensitiveMapUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.map;
+
+import org.apache.commons.collections4.map.CaseInsensitiveMap;
+import org.junit.Test;
+import org.springframework.util.LinkedCaseInsensitiveMap;
+import static org.junit.Assert.*;
+
+import java.util.TreeMap;
+
+public class CaseInsensitiveMapUnitTest {
+    @Test
+    public void givenCaseInsensitiveTreeMap_whenTwoEntriesAdded_thenSizeIsOne(){
+        TreeMap<String, Integer> treeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+        treeMap.put("abc", 1);
+        treeMap.put("ABC", 2);
+
+        assertEquals(treeMap.size(), 1);
+    }
+
+    @Test
+    public void givenCommonsCaseInsensitiveMap_whenSameEntryAdded_thenValueUpdated(){
+        CaseInsensitiveMap<String, Integer> commonsHashMap = new CaseInsensitiveMap<>();
+        commonsHashMap.put("abc", 1);
+        commonsHashMap.put("ABC", 2);
+
+        assertEquals(commonsHashMap.get("aBc"), (Integer)2);
+    }
+
+    @Test
+    public void givenLinkedCaseInsensitiveMap_whenEntryRemoved_thenSizeIsZero(){
+        LinkedCaseInsensitiveMap<Integer> linkedHashMap = new LinkedCaseInsensitiveMap<>();
+        linkedHashMap.put("abc", 3);
+        linkedHashMap.remove("aBC");
+
+        assertEquals(linkedHashMap.size(), 0);
+    }
+}