BAEL-6044: Fix the IllegalArgumentException: No enum const class (#13171)

core-java-modules/core-java-exceptions-4/src/main/java/com/baeldung/exception/noenumconst/Priority.java

@@ -0,0 +1,13 @@
+package com.baeldung.exception.noenumconst;
+
+public enum Priority {
+
+    HIGH("High"), MEDIUM("Medium"), LOW("Low");
+
+    private String name;
+
+    Priority(String name) {
+        this.name = name;
+    }
+
+}

core-java-modules/core-java-exceptions-4/src/main/java/com/baeldung/exception/noenumconst/PriorityUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.exception.noenumconst;
+
+public class PriorityUtils {
+
+    public static Priority getByName(String name) {
+        return Priority.valueOf(name);
+    }
+
+    public static Priority getByUpperCaseName(String name) {
+        if (name == null || name.isEmpty()) {
+            return null;
+        }
+
+        return Priority.valueOf(name.toUpperCase());
+    }
+
+    public static void main(String[] args) {
+        System.out.println(getByName("Low"));
+    }
+
+}

core-java-modules/core-java-exceptions-4/src/test/java/com/baeldung/exception/noenumconst/PriorityUtilsUnitTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.exception.noenumconst;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class PriorityUtilsUnitTest {
+
+    @Test
+    void givenCustomName_whenUsingGetByName_thenThrowIllegalArgumentException() {
+        assertThrows(IllegalArgumentException.class, () -> PriorityUtils.getByName("Low"));
+    }
+
+    @Test
+    void givenCustomName_whenUsingGetByUpperCaseName_thenReturnEnumConstant() {
+        assertEquals(Priority.HIGH, PriorityUtils.getByUpperCaseName("High"));
+    }
+
+    @Test
+    void givenInvalidCustomName_whenUsingGetByUpperCaseName_thenThrowIllegalArgumentException() {
+        assertThrows(IllegalArgumentException.class, () -> PriorityUtils.getByUpperCaseName("invalid"));
+    }
+
+    @Test
+    void givenEmptyName_whenUsingGetByUpperCaseName_thenReturnNull() {
+        assertNull(PriorityUtils.getByUpperCaseName(""));
+    }
+
+    @Test
+    void givenNull_whenUsingGetByUpperCaseName_thenReturnNull() {
+        assertNull(PriorityUtils.getByUpperCaseName(null));
+    }
+
+}