From c0157effb048677bc0ab4782c988a01f822c179a Mon Sep 17 00:00:00 2001
From: Kai Yuan <kent.yuan@Gmail.com>
Date: Sat, 14 Jan 2023 03:34:54 +0100
Subject: [PATCH] [List-CaseInsenContains] Case-Insensitive Searching in
 ArrayList (#13280)

---
 .../list/ignorecase/IgnoreCaseSearchUtil.java | 14 ++++++
 .../list/ignorecase/IgnoreCaseStringList.java | 29 ++++++++++++
 .../IgnoreCaseContainsUnitTest.java           | 45 +++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseSearchUtil.java
 create mode 100644 core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseStringList.java
 create mode 100644 core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/ignorecase/IgnoreCaseContainsUnitTest.java

diff --git a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseSearchUtil.java b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseSearchUtil.java
new file mode 100644
index 0000000000..38532ef031
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseSearchUtil.java
@@ -0,0 +1,14 @@
+package com.baeldung.list.ignorecase;
+
+import java.util.List;
+
+public class IgnoreCaseSearchUtil {
+    public static boolean ignoreCaseContains(List<String> theList, String searchStr) {
+        for (String s : theList) {
+            if (searchStr.equalsIgnoreCase(s)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseStringList.java b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseStringList.java
new file mode 100644
index 0000000000..a27c2650ed
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/ignorecase/IgnoreCaseStringList.java
@@ -0,0 +1,29 @@
+package com.baeldung.list.ignorecase;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+public class IgnoreCaseStringList extends ArrayList<String> {
+
+    public IgnoreCaseStringList() {
+
+    }
+
+    public IgnoreCaseStringList(Collection<? extends String> c) {
+        super(c);
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        String searchStr = (String) o;
+        // Using Stream API:
+        // return this.stream().anyMatch(searchStr::equalsIgnoreCase);
+        for (String s : this) {
+            if (searchStr.equalsIgnoreCase(s)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+}
diff --git a/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/ignorecase/IgnoreCaseContainsUnitTest.java b/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/ignorecase/IgnoreCaseContainsUnitTest.java
new file mode 100644
index 0000000000..5ca9bb1028
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/ignorecase/IgnoreCaseContainsUnitTest.java
@@ -0,0 +1,45 @@
+package com.baeldung.list.ignorecase;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class IgnoreCaseContainsUnitTest {
+    private static final List<String> LANGUAGES = Arrays.asList("Java", "Python", "Kotlin", "Ruby", "Javascript", "Go");
+
+    @Test
+    void givenStringList_whenCallTheStandardContains_shouldReturnFalse() {
+        String searchStr = "jAvA";
+        boolean result = LANGUAGES.contains(searchStr);
+        assertFalse(result);
+    }
+
+    @Test
+    void givenStringList_whenSearchIgnoreCaseUsingStreamAPI_shouldReturnTrue() {
+        String searchStr = "koTliN";
+        boolean result = LANGUAGES.stream().anyMatch(searchStr::equalsIgnoreCase);
+        assertTrue(result);
+    }
+
+    @Test
+    void givenStringList_whenUsingUtilClass_shouldReturnTrue() {
+        String searchStr = "ruBY";
+        boolean result = IgnoreCaseSearchUtil.ignoreCaseContains(LANGUAGES, searchStr);
+        assertTrue(result);
+    }
+
+    @Test
+    void givenStringList_whenUsingIgnoreCaseStringList_shouldReturnTrue() {
+        String searchStr = "pYtHoN";
+        List<String> ignoreCaseList = new IgnoreCaseStringList(LANGUAGES);
+        boolean result = ignoreCaseList.contains(searchStr);
+        assertTrue(result);
+
+        boolean resultContainAll = ignoreCaseList.containsAll(Arrays.asList("pYtHon", "jAvA", "koTliN", "ruBY"));
+        assertTrue(resultContainAll);
+    }
+}