Fix edge-case NullPointerException in

org.apache.commons.lang3.EnumUtils.getEnum(Class, String, E)

- Javadoc
- Fix some formatting

Author: garydgregory

src/changes/changes.xml

@@ -99,6 +99,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Fix edge-case NullPointerException in org.apache.commons.lang3.SystemUtils.isJavaVersionAtLeast(JavaVersion).</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Fix edge-case NullPointerException in org.apache.commons.lang3.SystemUtils.isJavaVersionAtMost(JavaVersion).</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Return the default enum if a SecurityException is caught in getEnumSystemProperty().</action>
+    <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Fix edge-case NullPointerException in org.apache.commons.lang3.EnumUtils.getEnum(Class, String, E).</action>
     <!-- ADD -->
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add Strings and refactor StringUtils.</action>
     <action issue="LANG-1747" type="add" dev="ggregory" due-to="Oliver B. Fischer, Gary Gregory">Add StopWatch.run([Failable]Runnable) and get([Failable]Supplier).</action>

src/main/java/org/apache/commons/lang3/EnumUtils.java

@@ -192,10 +192,10 @@ public static <E extends Enum<E>> long[] generateBitVectors(final Class<E> enumC
      * <p>This method differs from {@link Enum#valueOf} in that it does not throw an exception
      * for an invalid enum name.</p>
      *
-     * @param <E> the type of the enumeration
-     * @param enumClass  the class of the enum to query, not null
-     * @param enumName   the enum name, null returns null
-     * @return the enum, null if not found
+     * @param <E> the type of the enumeration.
+     * @param enumClass  the class of the enum to query, not null.
+     * @param enumName   the enum name, null returns null.
+     * @return the enum, null if not found.
      */
     public static <E extends Enum<E>> E getEnum(final Class<E> enumClass, final String enumName) {
         return getEnum(enumClass, enumName, null);
@@ -207,20 +207,20 @@ public static <E extends Enum<E>> E getEnum(final Class<E> enumClass, final Stri
      * <p>This method differs from {@link Enum#valueOf} in that it does not throw an exception
      * for an invalid enum name.</p>
      *
-     * @param <E> the type of the enumeration
-     * @param enumClass   the class of the enum to query, not null
-     * @param enumName    the enum name, null returns default enum
-     * @param defaultEnum the default enum
-     * @return the enum, default enum if not found
+     * @param <E> the type of the enumeration.
+     * @param enumClass   the class of the enum to query, null returns default enum.
+     * @param enumName    the enum name, null returns default enum.
+     * @param defaultEnum the default enum.
+     * @return the enum, default enum if not found.
      * @since 3.10
      */
     public static <E extends Enum<E>> E getEnum(final Class<E> enumClass, final String enumName, final E defaultEnum) {
-        if (enumName == null) {
+        if (enumClass == null || enumName == null) {
             return defaultEnum;
         }
         try {
             return Enum.valueOf(enumClass, enumName);
-        } catch (final IllegalArgumentException ex) {
+        } catch (final IllegalArgumentException e) {
             return defaultEnum;
         }
     }
@@ -320,10 +320,8 @@ public static <E extends Enum<E>, K> Map<K, E> getEnumMap(final Class<E> enumCla
      * @return the enum, default enum if not found.
      * @since 3.13.0
      */
-    public static <E extends Enum<E>> E getEnumSystemProperty(final Class<E> enumClass, final String propName,
-        final E defaultEnum) {
-        return enumClass == null || propName == null ? defaultEnum
-            : getEnum(enumClass, SystemProperties.getProperty(propName), defaultEnum);
+    public static <E extends Enum<E>> E getEnumSystemProperty(final Class<E> enumClass, final String propName, final E defaultEnum) {
+        return getEnum(enumClass, SystemProperties.getProperty(propName), defaultEnum);
     }
 
     /**
@@ -365,11 +363,11 @@ public static <E extends Enum<E>> E getFirstEnum(final Class<E> enumClass, final
      */
     public static <E extends Enum<E>> E getFirstEnumIgnoreCase(final Class<E> enumClass, final String enumName, final Function<E, String> stringFunction,
             final E defaultEnum) {
-            if (enumName == null || !enumClass.isEnum()) {
-                return defaultEnum;
-            }
-            return stream(enumClass).filter(e -> enumName.equalsIgnoreCase(stringFunction.apply(e))).findFirst().orElse(defaultEnum);
+        if (enumName == null || !enumClass.isEnum()) {
+            return defaultEnum;
         }
+        return stream(enumClass).filter(e -> enumName.equalsIgnoreCase(stringFunction.apply(e))).findFirst().orElse(defaultEnum);
+    }
 
     private static <E extends Enum<E>> boolean isEnum(final Class<E> enumClass) {
         return enumClass != null && !enumClass.isEnum();
@@ -378,13 +376,14 @@ private static <E extends Enum<E>> boolean isEnum(final Class<E> enumClass) {
     /**
      * Checks if the specified name is a valid enum for the class.
      *
-     * <p>This method differs from {@link Enum#valueOf} in that it checks if the name is
-     * a valid enum without needing to catch the exception.</p>
+     * <p>
+     * This method differs from {@link Enum#valueOf} in that it checks if the name is a valid enum without needing to catch the exception.
+     * </p>
      *
-     * @param <E> the type of the enumeration
-     * @param enumClass  the class of the enum to query, not null
-     * @param enumName   the enum name, null returns false
-     * @return true if the enum name is valid, otherwise false
+     * @param <E>       the type of the enumeration.
+     * @param enumClass the class of the enum to query, null returns false.
+     * @param enumName  the enum name, null returns false.
+     * @return true if the enum name is valid, otherwise false.
      */
     public static <E extends Enum<E>> boolean isValidEnum(final Class<E> enumClass, final String enumName) {
         return getEnum(enumClass, enumName) != null;
@@ -393,14 +392,15 @@ public static <E extends Enum<E>> boolean isValidEnum(final Class<E> enumClass,
     /**
      * Checks if the specified name is a valid enum for the class.
      *
-     * <p>This method differs from {@link Enum#valueOf} in that it checks if the name is
-     * a valid enum without needing to catch the exception
-     * and performs case insensitive matching of the name.</p>
+     * <p>
+     * This method differs from {@link Enum#valueOf} in that it checks if the name is a valid enum without needing to catch the exception and performs case
+     * insensitive matching of the name.
+     * </p>
      *
-     * @param <E> the type of the enumeration
-     * @param enumClass  the class of the enum to query, not null
-     * @param enumName   the enum name, null returns false
-     * @return true if the enum name is valid, otherwise false
+     * @param <E>       the type of the enumeration.
+     * @param enumClass the class of the enum to query, null returns false.
+     * @param enumName  the enum name, null returns false.
+     * @return true if the enum name is valid, otherwise false.
      * @since 3.8
      */
     public static <E extends Enum<E>> boolean isValidEnumIgnoreCase(final Class<E> enumClass, final String enumName) {

src/test/java/org/apache/commons/lang3/EnumUtilsTest.java

@@ -281,6 +281,7 @@ void testGetEnum_defaultEnum() {
         assertEquals(Traffic.GREEN, EnumUtils.getEnum(Traffic.class, null, Traffic.GREEN));
         assertEquals(Traffic.RED, EnumUtils.getEnum(Traffic.class, null, Traffic.RED));
         assertNull(EnumUtils.getEnum(Traffic.class, "PURPLE", null));
+        assertEquals(Traffic.AMBER, EnumUtils.getEnum(null, "RED", Traffic.AMBER));
     }
 
     /**
@@ -296,7 +297,7 @@ void testGetEnum_nonEnumClass() {
 
     @Test
     void testGetEnum_nullClass() {
-        assertNullPointerException(() -> EnumUtils.getEnum((Class<Traffic>) null, "PURPLE"));
+        assertNull(EnumUtils.getEnum((Class<Traffic>) null, "PURPLE"));
     }
 
     @Test
@@ -467,7 +468,7 @@ void testIsValidEnum() {
 
     @Test
     void testIsValidEnum_nullClass() {
-        assertNullPointerException(() -> EnumUtils.isValidEnum(null, "PURPLE"));
+        assertFalse(EnumUtils.isValidEnum(null, "PURPLE"));
     }
 
     @Test