Merge pull request #18743 from yabetancourt/BAEL-9387-List-of-String-Contains-Null-or-Empty

BAEL-9387 Check if a List of String contains null or empty

Author: davidmartinezbarua

core-java-modules/core-java-collections-list-8/src/test/java/com/baeldung/listwithnullorempty/ListNullOrEmptyUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.listwithnullorempty;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ListNullOrEmptyUnitTest {
+
+    List<String> list = Arrays.asList("Madrid", null, "  ", "Havana", "");
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckForNullOrEmptyUsingForLoop_thenReturnTrue() {
+        boolean hasNullOrEmpty = false;
+        for (String s : list) {
+            if (s == null || s.isEmpty()) {
+                hasNullOrEmpty = true;
+                break;
+            }
+        }
+
+        assertTrue(hasNullOrEmpty, "List should contain null or empty elements");
+    }
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckForNullOrEmptyUsingStreams_thenReturnTrue() {
+        boolean hasNullOrEmpty = list.stream()
+          .anyMatch(s -> s == null || s.isEmpty());
+
+        assertTrue(hasNullOrEmpty, "List should contain null or blank elements");
+    }
+
+    @Test
+    void givenListWithNullOrEmpty_whenCheckUsingParallelStream_thenReturnTrue() {
+        boolean hasNullOrEmpty = list.parallelStream()
+                .anyMatch(s -> s == null || s.isEmpty());
+
+        assertTrue(hasNullOrEmpty, "List should contain null or empty elements");
+    }
+
+}