001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3;
018
019import java.lang.reflect.Method;
020import java.lang.reflect.Modifier;
021import java.util.ArrayList;
022import java.util.Collections;
023import java.util.Comparator;
024import java.util.HashMap;
025import java.util.HashSet;
026import java.util.Iterator;
027import java.util.LinkedHashSet;
028import java.util.List;
029import java.util.Map;
030import java.util.Objects;
031import java.util.Set;
032import java.util.concurrent.atomic.AtomicReference;
033import java.util.stream.Collectors;
034
035/**
036 * Operates on classes without using reflection.
037 *
038 * <p>
039 * This class handles invalid {@code null} inputs as best it can. Each method documents its behavior in more detail.
040 * </p>
041 *
042 * <p>
043 * The notion of a {@code canonical name} includes the human-readable name for the type, for example {@code int[]}. The
044 * non-canonical method variants work with the JVM names, such as {@code [I}.
045 * </p>
046 *
047 * @since 2.0
048 */
049public class ClassUtils {
050
051    /**
052     * Inclusivity literals for {@link #hierarchy(Class, Interfaces)}.
053     *
054     * @since 3.2
055     */
056    public enum Interfaces {
057
058        /** Includes interfaces. */
059        INCLUDE,
060
061        /** Excludes interfaces. */
062        EXCLUDE
063    }
064
065    /**
066     * The maximum number of array dimensions.
067     */
068    private static final int MAX_DIMENSIONS = 255;
069
070    private static final Comparator<Class<?>> COMPARATOR = (o1, o2) -> Objects.compare(getName(o1), getName(o2), String::compareTo);
071
072    /**
073     * The package separator character: {@code '&#x2e;' == {@value}}.
074     */
075    public static final char PACKAGE_SEPARATOR_CHAR = '.';
076
077    /**
078     * The package separator String: {@code "&#x2e;"}.
079     */
080    public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);
081
082    /**
083     * The inner class separator character: {@code '$' == {@value}}.
084     */
085    public static final char INNER_CLASS_SEPARATOR_CHAR = '$';
086
087    /**
088     * The inner class separator String: {@code "$"}.
089     */
090    public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);
091
092    /**
093     * Maps names of primitives to their corresponding primitive {@link Class}es.
094     */
095    private static final Map<String, Class<?>> NAME_PRIMITIVE_MAP = new HashMap<>();
096
097    static {
098        NAME_PRIMITIVE_MAP.put(Boolean.TYPE.getName(), Boolean.TYPE);
099        NAME_PRIMITIVE_MAP.put(Byte.TYPE.getName(), Byte.TYPE);
100        NAME_PRIMITIVE_MAP.put(Character.TYPE.getName(), Character.TYPE);
101        NAME_PRIMITIVE_MAP.put(Double.TYPE.getName(), Double.TYPE);
102        NAME_PRIMITIVE_MAP.put(Float.TYPE.getName(), Float.TYPE);
103        NAME_PRIMITIVE_MAP.put(Integer.TYPE.getName(), Integer.TYPE);
104        NAME_PRIMITIVE_MAP.put(Long.TYPE.getName(), Long.TYPE);
105        NAME_PRIMITIVE_MAP.put(Short.TYPE.getName(), Short.TYPE);
106        NAME_PRIMITIVE_MAP.put(Void.TYPE.getName(), Void.TYPE);
107    }
108
109    /**
110     * Maps primitive {@link Class}es to their corresponding wrapper {@link Class}.
111     */
112    private static final Map<Class<?>, Class<?>> PRIMITIVE_WRAPPER_MAP = new HashMap<>();
113
114    static {
115        PRIMITIVE_WRAPPER_MAP.put(Boolean.TYPE, Boolean.class);
116        PRIMITIVE_WRAPPER_MAP.put(Byte.TYPE, Byte.class);
117        PRIMITIVE_WRAPPER_MAP.put(Character.TYPE, Character.class);
118        PRIMITIVE_WRAPPER_MAP.put(Short.TYPE, Short.class);
119        PRIMITIVE_WRAPPER_MAP.put(Integer.TYPE, Integer.class);
120        PRIMITIVE_WRAPPER_MAP.put(Long.TYPE, Long.class);
121        PRIMITIVE_WRAPPER_MAP.put(Double.TYPE, Double.class);
122        PRIMITIVE_WRAPPER_MAP.put(Float.TYPE, Float.class);
123        PRIMITIVE_WRAPPER_MAP.put(Void.TYPE, Void.TYPE);
124    }
125
126    /**
127     * Maps wrapper {@link Class}es to their corresponding primitive types.
128     */
129    private static final Map<Class<?>, Class<?>> WRAPPER_PRIMITIVE_MAP = new HashMap<>();
130
131    static {
132        PRIMITIVE_WRAPPER_MAP.forEach((primitiveClass, wrapperClass) -> {
133            if (!primitiveClass.equals(wrapperClass)) {
134                WRAPPER_PRIMITIVE_MAP.put(wrapperClass, primitiveClass);
135            }
136        });
137    }
138
139    /**
140     * Maps a primitive class name to its corresponding abbreviation used in array class names.
141     */
142    private static final Map<String, String> ABBREVIATION_MAP;
143
144    /**
145     * Maps an abbreviation used in array class names to corresponding primitive class name.
146     */
147    private static final Map<String, String> REVERSE_ABBREVIATION_MAP;
148
149    /** Feed abbreviation maps. */
150    static {
151        final Map<String, String> map = new HashMap<>();
152        map.put(Integer.TYPE.getName(), "I");
153        map.put(Boolean.TYPE.getName(), "Z");
154        map.put(Float.TYPE.getName(), "F");
155        map.put(Long.TYPE.getName(), "J");
156        map.put(Short.TYPE.getName(), "S");
157        map.put(Byte.TYPE.getName(), "B");
158        map.put(Double.TYPE.getName(), "D");
159        map.put(Character.TYPE.getName(), "C");
160        ABBREVIATION_MAP = Collections.unmodifiableMap(map);
161        REVERSE_ABBREVIATION_MAP = Collections.unmodifiableMap(map.entrySet().stream().collect(Collectors.toMap(Map.Entry::getValue, Map.Entry::getKey)));
162    }
163
164    /**
165     * Gets the class comparator, comparing by class name.
166     *
167     * @return the class comparator.
168     * @since 3.13.0
169     */
170    public static Comparator<Class<?>> comparator() {
171        return COMPARATOR;
172    }
173
174    /**
175     * Given a {@link List} of {@link Class} objects, this method converts them into class names.
176     *
177     * <p>
178     * A new {@link List} is returned. {@code null} objects will be copied into the returned list as {@code null}.
179     * </p>
180     *
181     * @param classes the classes to change
182     * @return a {@link List} of class names corresponding to the Class objects, {@code null} if null input
183     * @throws ClassCastException if {@code classes} contains a non-{@link Class} entry
184     */
185    public static List<String> convertClassesToClassNames(final List<Class<?>> classes) {
186        return classes == null ? null : classes.stream().map(e -> getName(e, null)).collect(Collectors.toList());
187    }
188
189    /**
190     * Given a {@link List} of class names, this method converts them into classes.
191     *
192     * <p>
193     * A new {@link List} is returned. If the class name cannot be found, {@code null} is stored in the {@link List}. If the
194     * class name in the {@link List} is {@code null}, {@code null} is stored in the output {@link List}.
195     * </p>
196     *
197     * @param classNames the classNames to change
198     * @return a {@link List} of Class objects corresponding to the class names, {@code null} if null input
199     * @throws ClassCastException if classNames contains a non String entry
200     */
201    public static List<Class<?>> convertClassNamesToClasses(final List<String> classNames) {
202        if (classNames == null) {
203            return null;
204        }
205        final List<Class<?>> classes = new ArrayList<>(classNames.size());
206        classNames.forEach(className -> {
207            try {
208                classes.add(Class.forName(className));
209            } catch (final Exception ex) {
210                classes.add(null);
211            }
212        });
213        return classes;
214    }
215
216    /**
217     * Gets the abbreviated name of a {@link Class}.
218     *
219     * @param cls the class to get the abbreviated name for, may be {@code null}
220     * @param lengthHint the desired length of the abbreviated name
221     * @return the abbreviated name or an empty string
222     * @throws IllegalArgumentException if len &lt;= 0
223     * @see #getAbbreviatedName(String, int)
224     * @since 3.4
225     */
226    public static String getAbbreviatedName(final Class<?> cls, final int lengthHint) {
227        if (cls == null) {
228            return StringUtils.EMPTY;
229        }
230        return getAbbreviatedName(cls.getName(), lengthHint);
231    }
232
233    /**
234     * Gets the abbreviated class name from a {@link String}.
235     *
236     * <p>
237     * The string passed in is assumed to be a class name - it is not checked.
238     * </p>
239     *
240     * <p>
241     * The abbreviation algorithm will shorten the class name, usually without significant loss of meaning.
242     * </p>
243     *
244     * <p>
245     * The abbreviated class name will always include the complete package hierarchy. If enough space is available,
246     * rightmost sub-packages will be displayed in full length. The abbreviated package names will be shortened to a single
247     * character.
248     * </p>
249     * <p>
250     * Only package names are shortened, the class simple name remains untouched. (See examples.)
251     * </p>
252     * <p>
253     * The result will be longer than the desired length only if all the package names shortened to a single character plus
254     * the class simple name with the separating dots together are longer than the desired length. In other words, when the
255     * class name cannot be shortened to the desired length.
256     * </p>
257     * <p>
258     * If the class name can be shortened then the final length will be at most {@code lengthHint} characters.
259     * </p>
260     * <p>
261     * If the {@code lengthHint} is zero or negative then the method throws exception. If you want to achieve the shortest
262     * possible version then use {@code 1} as a {@code lengthHint}.
263     * </p>
264     *
265     * <table>
266     * <caption>Examples</caption>
267     * <tr>
268     * <td>className</td>
269     * <td>len</td>
270     * <td>return</td>
271     * </tr>
272     * <tr>
273     * <td>null</td>
274     * <td>1</td>
275     * <td>""</td>
276     * </tr>
277     * <tr>
278     * <td>"java.lang.String"</td>
279     * <td>5</td>
280     * <td>"j.l.String"</td>
281     * </tr>
282     * <tr>
283     * <td>"java.lang.String"</td>
284     * <td>15</td>
285     * <td>"j.lang.String"</td>
286     * </tr>
287     * <tr>
288     * <td>"java.lang.String"</td>
289     * <td>30</td>
290     * <td>"java.lang.String"</td>
291     * </tr>
292     * <tr>
293     * <td>"org.apache.commons.lang3.ClassUtils"</td>
294     * <td>18</td>
295     * <td>"o.a.c.l.ClassUtils"</td>
296     * </tr>
297     * </table>
298     *
299     * @param className the className to get the abbreviated name for, may be {@code null}
300     * @param lengthHint the desired length of the abbreviated name
301     * @return the abbreviated name or an empty string if the specified class name is {@code null} or empty string. The
302     *         abbreviated name may be longer than the desired length if it cannot be abbreviated to the desired length.
303     * @throws IllegalArgumentException if {@code len <= 0}
304     * @since 3.4
305     */
306    public static String getAbbreviatedName(final String className, final int lengthHint) {
307        if (lengthHint <= 0) {
308            throw new IllegalArgumentException("len must be > 0");
309        }
310        if (className == null) {
311            return StringUtils.EMPTY;
312        }
313        if (className.length() <= lengthHint) {
314            return className;
315        }
316        final char[] abbreviated = className.toCharArray();
317        int target = 0;
318        int source = 0;
319        while (source < abbreviated.length) {
320            // copy the next part
321            int runAheadTarget = target;
322            while (source < abbreviated.length && abbreviated[source] != '.') {
323                abbreviated[runAheadTarget++] = abbreviated[source++];
324            }
325
326            ++target;
327            if (useFull(runAheadTarget, source, abbreviated.length, lengthHint) || target > runAheadTarget) {
328                target = runAheadTarget;
329            }
330
331            // copy the '.' unless it was the last part
332            if (source < abbreviated.length) {
333                abbreviated[target++] = abbreviated[source++];
334            }
335        }
336        return new String(abbreviated, 0, target);
337    }
338
339    /**
340     * Gets a {@link List} of all interfaces implemented by the given class and its superclasses.
341     *
342     * <p>
343     * The order is determined by looking through each interface in turn as declared in the source file and following its
344     * hierarchy up. Then each superclass is considered in the same way. Later duplicates are ignored, so the order is
345     * maintained.
346     * </p>
347     *
348     * @param cls the class to look up, may be {@code null}
349     * @return the {@link List} of interfaces in order, {@code null} if null input
350     */
351    public static List<Class<?>> getAllInterfaces(final Class<?> cls) {
352        if (cls == null) {
353            return null;
354        }
355        final LinkedHashSet<Class<?>> interfacesFound = new LinkedHashSet<>();
356        getAllInterfaces(cls, interfacesFound);
357        return new ArrayList<>(interfacesFound);
358    }
359
360    /**
361     * Gets the interfaces for the specified class.
362     *
363     * @param cls the class to look up, may be {@code null}
364     * @param interfacesFound the {@link Set} of interfaces for the class
365     */
366    private static void getAllInterfaces(Class<?> cls, final HashSet<Class<?>> interfacesFound) {
367        while (cls != null) {
368            final Class<?>[] interfaces = cls.getInterfaces();
369            for (final Class<?> i : interfaces) {
370                if (interfacesFound.add(i)) {
371                    getAllInterfaces(i, interfacesFound);
372                }
373            }
374            cls = cls.getSuperclass();
375        }
376    }
377
378    /**
379     * Gets a {@link List} of superclasses for the given class.
380     *
381     * @param cls the class to look up, may be {@code null}
382     * @return the {@link List} of superclasses in order going up from this one {@code null} if null input
383     */
384    public static List<Class<?>> getAllSuperclasses(final Class<?> cls) {
385        if (cls == null) {
386            return null;
387        }
388        final List<Class<?>> classes = new ArrayList<>();
389        Class<?> superclass = cls.getSuperclass();
390        while (superclass != null) {
391            classes.add(superclass);
392            superclass = superclass.getSuperclass();
393        }
394        return classes;
395    }
396
397    /**
398     * Gets the canonical class name for a {@link Class}.
399     *
400     * @param cls the class for which to get the canonical class name; may be null
401     * @return the canonical name of the class, or the empty String
402     * @since 3.7
403     * @see Class#getCanonicalName()
404     */
405    public static String getCanonicalName(final Class<?> cls) {
406        return getCanonicalName(cls, StringUtils.EMPTY);
407    }
408
409    /**
410     * Gets the canonical name for a {@link Class}.
411     *
412     * @param cls the class for which to get the canonical class name; may be null
413     * @param valueIfNull the return value if null
414     * @return the canonical name of the class, or {@code valueIfNull}
415     * @since 3.7
416     * @see Class#getCanonicalName()
417     */
418    public static String getCanonicalName(final Class<?> cls, final String valueIfNull) {
419        if (cls == null) {
420            return valueIfNull;
421        }
422        final String canonicalName = cls.getCanonicalName();
423        return canonicalName == null ? valueIfNull : canonicalName;
424    }
425
426    /**
427     * Gets the canonical name for an {@link Object}.
428     *
429     * @param object the object for which to get the canonical class name; may be null
430     * @return the canonical name of the object, or the empty String
431     * @since 3.7
432     * @see Class#getCanonicalName()
433     */
434    public static String getCanonicalName(final Object object) {
435        return getCanonicalName(object, StringUtils.EMPTY);
436    }
437
438    /**
439     * Gets the canonical name for an {@link Object}.
440     *
441     * @param object the object for which to get the canonical class name; may be null
442     * @param valueIfNull the return value if null
443     * @return the canonical name of the object or {@code valueIfNull}
444     * @since 3.7
445     * @see Class#getCanonicalName()
446     */
447    public static String getCanonicalName(final Object object, final String valueIfNull) {
448        if (object == null) {
449            return valueIfNull;
450        }
451        final String canonicalName = object.getClass().getCanonicalName();
452        return canonicalName == null ? valueIfNull : canonicalName;
453    }
454
455    /**
456     * Converts a given name of class into canonical format. If name of class is not a name of array class it returns
457     * unchanged name.
458     *
459     * <p>
460     * The method does not change the {@code $} separators in case the class is inner class.
461     * </p>
462     *
463     * <p>
464     * Example:
465     * <ul>
466     * <li>{@code getCanonicalName("[I") = "int[]"}</li>
467     * <li>{@code getCanonicalName("[Ljava.lang.String;") = "java.lang.String[]"}</li>
468     * <li>{@code getCanonicalName("java.lang.String") = "java.lang.String"}</li>
469     * </ul>
470     * </p>
471     *
472     * @param name the name of class.
473     * @return canonical form of class name.
474     * @throws IllegalArgumentException if the class name is invalid
475     */
476    private static String getCanonicalName(final String name) {
477        String className = StringUtils.deleteWhitespace(name);
478        if (className == null) {
479            return null;
480        }
481        int dim = 0;
482        final int len = className.length();
483        while (dim < len && className.charAt(dim) == '[') {
484            dim++;
485            if (dim > MAX_DIMENSIONS) {
486                throw new IllegalArgumentException(String.format("Maximum array dimension %d exceeded", MAX_DIMENSIONS));
487            }
488        }
489        if (dim >= len) {
490            throw new IllegalArgumentException(String.format("Invalid class name %s", name));
491        }
492        if (dim < 1) {
493            return className;
494        }
495        className = className.substring(dim);
496        if (className.startsWith("L")) {
497            if (!className.endsWith(";") || className.length() < 3) {
498                throw new IllegalArgumentException(String.format("Invalid class name %s", name));
499            }
500            className = className.substring(1, className.length() - 1);
501        } else if (className.length() == 1) {
502            final String primitive = REVERSE_ABBREVIATION_MAP.get(className.substring(0, 1));
503            if (primitive == null) {
504                throw new IllegalArgumentException(String.format("Invalid class name %s", name));
505            }
506            className = primitive;
507        } else {
508            throw new IllegalArgumentException(String.format("Invalid class name %s", name));
509        }
510        final StringBuilder canonicalClassNameBuffer = new StringBuilder(className.length() + dim * 2);
511        canonicalClassNameBuffer.append(className);
512        for (int i = 0; i < dim; i++) {
513            canonicalClassNameBuffer.append("[]");
514        }
515        return canonicalClassNameBuffer.toString();
516    }
517
518    /**
519     * Gets the (initialized) class represented by {@code className} using the {@code classLoader}. This implementation
520     * supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
521     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
522     *
523     * @param classLoader the class loader to use to load the class
524     * @param className the class name
525     * @return the class represented by {@code className} using the {@code classLoader}
526     * @throws NullPointerException if the className is null
527     * @throws ClassNotFoundException if the class is not found
528     */
529    public static Class<?> getClass(final ClassLoader classLoader, final String className) throws ClassNotFoundException {
530        return getClass(classLoader, className, true);
531    }
532
533    /**
534     * Gets the class represented by {@code className} using the {@code classLoader}. This implementation supports the
535     * syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}", and
536     * "{@code [Ljava.util.Map$Entry;}".
537     *
538     * @param classLoader the class loader to use to load the class
539     * @param className the class name
540     * @param initialize whether the class must be initialized
541     * @return the class represented by {@code className} using the {@code classLoader}
542     * @throws NullPointerException if the className is null
543     * @throws ClassNotFoundException if the class is not found
544     */
545    public static Class<?> getClass(final ClassLoader classLoader, final String className, final boolean initialize) throws ClassNotFoundException {
546        // This method was re-written to avoid recursion and stack overflows found by fuzz testing.
547        String next = className;
548        int lastDotIndex = -1;
549        do {
550            try {
551                final Class<?> clazz = getPrimitiveClass(next);
552                return clazz != null ? clazz : Class.forName(toCanonicalName(next), initialize, classLoader);
553            } catch (final ClassNotFoundException ex) {
554                lastDotIndex = next.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
555                if (lastDotIndex != -1) {
556                    next = next.substring(0, lastDotIndex) + INNER_CLASS_SEPARATOR_CHAR + next.substring(lastDotIndex + 1);
557                }
558            }
559        } while (lastDotIndex != -1);
560        throw new ClassNotFoundException(next);
561    }
562
563    /**
564     * Gets the (initialized) class represented by {@code className} using the current thread's context class loader.
565     * This implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
566     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
567     *
568     * @param className the class name
569     * @return the class represented by {@code className} using the current thread's context class loader
570     * @throws NullPointerException if the className is null
571     * @throws ClassNotFoundException if the class is not found
572     */
573    public static Class<?> getClass(final String className) throws ClassNotFoundException {
574        return getClass(className, true);
575    }
576
577    /**
578     * Gets the class represented by {@code className} using the current thread's context class loader. This
579     * implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
580     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
581     *
582     * @param className the class name
583     * @param initialize whether the class must be initialized
584     * @return the class represented by {@code className} using the current thread's context class loader
585     * @throws NullPointerException if the className is null
586     * @throws ClassNotFoundException if the class is not found
587     */
588    public static Class<?> getClass(final String className, final boolean initialize) throws ClassNotFoundException {
589        final ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
590        final ClassLoader loader = contextCL == null ? ClassUtils.class.getClassLoader() : contextCL;
591        return getClass(loader, className, initialize);
592    }
593
594    /**
595     * Delegates to {@link Class#getComponentType()} using generics.
596     *
597     * @param <T> The array class type.
598     * @param cls A class or null.
599     * @return The array component type or null.
600     * @see Class#getComponentType()
601     * @since 3.13.0
602     */
603    @SuppressWarnings("unchecked")
604    public static <T> Class<T> getComponentType(final Class<T[]> cls) {
605        return cls == null ? null : (Class<T>) cls.getComponentType();
606    }
607
608    /**
609     * Null-safe version of {@code cls.getName()}
610     *
611     * @param cls the class for which to get the class name; may be null
612     * @return the class name or the empty string in case the argument is {@code null}
613     * @since 3.7
614     * @see Class#getSimpleName()
615     */
616    public static String getName(final Class<?> cls) {
617        return getName(cls, StringUtils.EMPTY);
618    }
619
620    /**
621     * Null-safe version of {@code cls.getName()}
622     *
623     * @param cls the class for which to get the class name; may be null
624     * @param valueIfNull the return value if the argument {@code cls} is {@code null}
625     * @return the class name or {@code valueIfNull}
626     * @since 3.7
627     * @see Class#getName()
628     */
629    public static String getName(final Class<?> cls, final String valueIfNull) {
630        return getName(cls, valueIfNull, false);
631    }
632
633    static String getName(final Class<?> cls, final String valueIfNull, final boolean simple) {
634        return cls == null ? valueIfNull : simple ? cls.getSimpleName() : cls.getName();
635    }
636
637    /**
638     * Null-safe version of {@code object.getClass().getName()}
639     *
640     * @param object the object for which to get the class name; may be null
641     * @return the class name or the empty String
642     * @since 3.7
643     * @see Class#getSimpleName()
644     */
645    public static String getName(final Object object) {
646        return getName(object, StringUtils.EMPTY);
647    }
648
649    /**
650     * Null-safe version of {@code object.getClass().getSimpleName()}
651     *
652     * @param object the object for which to get the class name; may be null
653     * @param valueIfNull the value to return if {@code object} is {@code null}
654     * @return the class name or {@code valueIfNull}
655     * @since 3.0
656     * @see Class#getName()
657     */
658    public static String getName(final Object object, final String valueIfNull) {
659        return object == null ? valueIfNull : object.getClass().getName();
660    }
661
662    /**
663     * Gets the package name from the canonical name of a {@link Class}.
664     *
665     * @param cls the class to get the package name for, may be {@code null}.
666     * @return the package name or an empty string
667     * @since 2.4
668     */
669    public static String getPackageCanonicalName(final Class<?> cls) {
670        if (cls == null) {
671            return StringUtils.EMPTY;
672        }
673        return getPackageCanonicalName(cls.getName());
674    }
675
676    /**
677     * Gets the package name from the class name of an {@link Object}.
678     *
679     * @param object the class to get the package name for, may be null
680     * @param valueIfNull the value to return if null
681     * @return the package name of the object, or the null value
682     * @since 2.4
683     */
684    public static String getPackageCanonicalName(final Object object, final String valueIfNull) {
685        if (object == null) {
686            return valueIfNull;
687        }
688        return getPackageCanonicalName(object.getClass().getName());
689    }
690
691    /**
692     * Gets the package name from the class name.
693     *
694     * <p>
695     * The string passed in is assumed to be a class name - it is not checked.
696     * </p>
697     * <p>
698     * If the class is in the default package, return an empty string.
699     * </p>
700     *
701     * @param name the name to get the package name for, may be {@code null}
702     * @return the package name or an empty string
703     * @since 2.4
704     */
705    public static String getPackageCanonicalName(final String name) {
706        return getPackageName(getCanonicalName(name));
707    }
708
709    /**
710     * Gets the package name of a {@link Class}.
711     *
712     * @param cls the class to get the package name for, may be {@code null}.
713     * @return the package name or an empty string
714     */
715    public static String getPackageName(final Class<?> cls) {
716        if (cls == null) {
717            return StringUtils.EMPTY;
718        }
719        return getPackageName(cls.getName());
720    }
721
722    /**
723     * Gets the package name of an {@link Object}.
724     *
725     * @param object the class to get the package name for, may be null
726     * @param valueIfNull the value to return if null
727     * @return the package name of the object, or the null value
728     */
729    public static String getPackageName(final Object object, final String valueIfNull) {
730        if (object == null) {
731            return valueIfNull;
732        }
733        return getPackageName(object.getClass());
734    }
735
736    /**
737     * Gets the package name from a {@link String}.
738     *
739     * <p>
740     * The string passed in is assumed to be a class name.
741     * </p>
742     * <p>
743     * If the class is unpackaged, return an empty string.
744     * </p>
745     *
746     * @param className the className to get the package name for, may be {@code null}.
747     * @return the package name or an empty string.
748     */
749    public static String getPackageName(String className) {
750        if (StringUtils.isEmpty(className)) {
751            return StringUtils.EMPTY;
752        }
753        int i = 0;
754        // Strip array encoding
755        while (className.charAt(i) == '[') {
756            i++;
757        }
758        className = className.substring(i);
759        // Strip Object type encoding
760        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
761            className = className.substring(1);
762        }
763        i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
764        if (i == -1) {
765            return StringUtils.EMPTY;
766        }
767        return className.substring(0, i);
768    }
769
770    /**
771     * Gets the primitive class for the given class name, for example "byte".
772     *
773     * @param className the primitive class for the given class name.
774     * @return the primitive class.
775     */
776    static Class<?> getPrimitiveClass(final String className) {
777        return NAME_PRIMITIVE_MAP.get(className);
778    }
779
780    /**
781     * Gets the desired Method much like {@code Class.getMethod}, however it ensures that the returned Method is from a
782     * public class or interface and not from an anonymous inner class. This means that the Method is invokable and doesn't
783     * fall foul of Java bug (<a href="https://bugs.java.com/bugdatabase/view_bug.do?bug_id=4071957">4071957</a>).
784     *
785     * <pre>
786     *  {@code Set set = Collections.unmodifiableSet(...);
787     *  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);
788     *  Object result = method.invoke(set, new Object[]);}
789     * </pre>
790     *
791     * @param cls the class to check, not null
792     * @param methodName the name of the method
793     * @param parameterTypes the list of parameters
794     * @return the method
795     * @throws NullPointerException if the class is null
796     * @throws SecurityException if a security violation occurred
797     * @throws NoSuchMethodException if the method is not found in the given class or if the method doesn't conform with the
798     *         requirements
799     */
800    public static Method getPublicMethod(final Class<?> cls, final String methodName, final Class<?>... parameterTypes) throws NoSuchMethodException {
801        final Method declaredMethod = cls.getMethod(methodName, parameterTypes);
802        if (isPublic(declaredMethod.getDeclaringClass())) {
803            return declaredMethod;
804        }
805        final List<Class<?>> candidateClasses = new ArrayList<>(getAllInterfaces(cls));
806        candidateClasses.addAll(getAllSuperclasses(cls));
807        for (final Class<?> candidateClass : candidateClasses) {
808            if (!isPublic(candidateClass)) {
809                continue;
810            }
811            final Method candidateMethod;
812            try {
813                candidateMethod = candidateClass.getMethod(methodName, parameterTypes);
814            } catch (final NoSuchMethodException ex) {
815                continue;
816            }
817            if (Modifier.isPublic(candidateMethod.getDeclaringClass().getModifiers())) {
818                return candidateMethod;
819            }
820        }
821        throw new NoSuchMethodException("Can't find a public method for " + methodName + " " + ArrayUtils.toString(parameterTypes));
822    }
823
824    /**
825     * Gets the canonical name minus the package name from a {@link Class}.
826     *
827     * @param cls the class for which to get the short canonical class name; may be null
828     * @return the canonical name without the package name or an empty string
829     * @since 2.4
830     * @see Class#getCanonicalName()
831     */
832    public static String getShortCanonicalName(final Class<?> cls) {
833        return cls == null ? StringUtils.EMPTY : getShortCanonicalName(cls.getCanonicalName());
834    }
835
836    /**
837     * Gets the canonical name minus the package name for an {@link Object}.
838     *
839     * @param object the class to get the short name for, may be null
840     * @param valueIfNull the value to return if null
841     * @return the canonical name of the object without the package name, or the null value
842     * @since 2.4
843     * @see Class#getCanonicalName()
844     */
845    public static String getShortCanonicalName(final Object object, final String valueIfNull) {
846        return object == null ? valueIfNull : getShortCanonicalName(object.getClass());
847    }
848
849    /**
850     * Gets the canonical name minus the package name from a String.
851     *
852     * <p>
853     * The string passed in is assumed to be a class name - it is not checked.
854     * </p>
855     *
856     * <p>
857     * Note that this method is mainly designed to handle the arrays and primitives properly. If the class is an inner class
858     * then the result value will not contain the outer classes. This way the behavior of this method is different from
859     * {@link #getShortClassName(String)}. The argument in that case is class name and not canonical name and the return
860     * value retains the outer classes.
861     * </p>
862     *
863     * <p>
864     * Note that there is no way to reliably identify the part of the string representing the package hierarchy and the part
865     * that is the outer class or classes in case of an inner class. Trying to find the class would require reflective call
866     * and the class itself may not even be on the class path. Relying on the fact that class names start with capital
867     * letter and packages with lower case is heuristic.
868     * </p>
869     *
870     * <p>
871     * It is recommended to use {@link #getShortClassName(String)} for cases when the class is an inner class and use this
872     * method for cases it is designed for.
873     * </p>
874     *
875     * <table>
876     * <caption>Examples</caption>
877     * <tr>
878     * <td>return value</td>
879     * <td>input</td>
880     * </tr>
881     * <tr>
882     * <td>{@code ""}</td>
883     * <td>{@code (String) null}</td>
884     * </tr>
885     * <tr>
886     * <td>{@code "Map.Entry"}</td>
887     * <td>{@code java.util.Map.Entry.class.getName()}</td>
888     * </tr>
889     * <tr>
890     * <td>{@code "Entry"}</td>
891     * <td>{@code java.util.Map.Entry.class.getCanonicalName()}</td>
892     * </tr>
893     * <tr>
894     * <td>{@code "ClassUtils"}</td>
895     * <td>{@code "org.apache.commons.lang3.ClassUtils"}</td>
896     * </tr>
897     * <tr>
898     * <td>{@code "ClassUtils[]"}</td>
899     * <td>{@code "[Lorg.apache.commons.lang3.ClassUtils;"}</td>
900     * </tr>
901     * <tr>
902     * <td>{@code "ClassUtils[][]"}</td>
903     * <td>{@code "[[Lorg.apache.commons.lang3.ClassUtils;"}</td>
904     * </tr>
905     * <tr>
906     * <td>{@code "ClassUtils[]"}</td>
907     * <td>{@code "org.apache.commons.lang3.ClassUtils[]"}</td>
908     * </tr>
909     * <tr>
910     * <td>{@code "ClassUtils[][]"}</td>
911     * <td>{@code "org.apache.commons.lang3.ClassUtils[][]"}</td>
912     * </tr>
913     * <tr>
914     * <td>{@code "int[]"}</td>
915     * <td>{@code "[I"}</td>
916     * </tr>
917     * <tr>
918     * <td>{@code "int[]"}</td>
919     * <td>{@code int[].class.getCanonicalName()}</td>
920     * </tr>
921     * <tr>
922     * <td>{@code "int[]"}</td>
923     * <td>{@code int[].class.getName()}</td>
924     * </tr>
925     * <tr>
926     * <td>{@code "int[][]"}</td>
927     * <td>{@code "[[I"}</td>
928     * </tr>
929     * <tr>
930     * <td>{@code "int[]"}</td>
931     * <td>{@code "int[]"}</td>
932     * </tr>
933     * <tr>
934     * <td>{@code "int[][]"}</td>
935     * <td>{@code "int[][]"}</td>
936     * </tr>
937     * </table>
938     *
939     * @param canonicalName the class name to get the short name for
940     * @return the canonical name of the class without the package name or an empty string
941     * @since 2.4
942     */
943    public static String getShortCanonicalName(final String canonicalName) {
944        return getShortClassName(getCanonicalName(canonicalName));
945    }
946
947    /**
948     * Gets the class name minus the package name from a {@link Class}.
949     *
950     * <p>
951     * This method simply gets the name using {@code Class.getName()} and then calls {@link #getShortClassName(String)}. See
952     * relevant notes there.
953     * </p>
954     *
955     * @param cls the class to get the short name for.
956     * @return the class name without the package name or an empty string. If the class is an inner class then the returned
957     *         value will contain the outer class or classes separated with {@code .} (dot) character.
958     */
959    public static String getShortClassName(final Class<?> cls) {
960        if (cls == null) {
961            return StringUtils.EMPTY;
962        }
963        return getShortClassName(cls.getName());
964    }
965
966    /**
967     * Gets the class name of the {@code object} without the package name or names.
968     *
969     * <p>
970     * The method looks up the class of the object and then converts the name of the class invoking
971     * {@link #getShortClassName(Class)} (see relevant notes there).
972     * </p>
973     *
974     * @param object the class to get the short name for, may be {@code null}
975     * @param valueIfNull the value to return if the object is {@code null}
976     * @return the class name of the object without the package name, or {@code valueIfNull} if the argument {@code object}
977     *         is {@code null}
978     */
979    public static String getShortClassName(final Object object, final String valueIfNull) {
980        if (object == null) {
981            return valueIfNull;
982        }
983        return getShortClassName(object.getClass());
984    }
985
986    /**
987     * Gets the class name minus the package name from a String.
988     *
989     * <p>
990     * The string passed in is assumed to be a class name - it is not checked. The string has to be formatted the way as the
991     * JDK method {@code Class.getName()} returns it, and not the usual way as we write it, for example in import
992     * statements, or as it is formatted by {@code Class.getCanonicalName()}.
993     * </p>
994     *
995     * <p>
996     * The difference is significant only in case of classes that are inner classes of some other classes. In this case
997     * the separator between the outer and inner class (possibly on multiple hierarchy level) has to be {@code $} (dollar
998     * sign) and not {@code .} (dot), as it is returned by {@code Class.getName()}
999     * </p>
1000     *
1001     * <p>
1002     * Note that this method is called from the {@link #getShortClassName(Class)} method using the string returned by
1003     * {@code Class.getName()}.
1004     * </p>
1005     *
1006     * <p>
1007     * Note that this method differs from {@link #getSimpleName(Class)} in that this will return, for example
1008     * {@code "Map.Entry"} whilst the {@link Class} variant will simply return {@code "Entry"}. In this example
1009     * the argument {@code className} is the string {@code java.util.Map$Entry} (note the {@code $} sign).
1010     * </p>
1011     *
1012     * @param className the className to get the short name for. It has to be formatted as returned by
1013     *        {@code Class.getName()} and not {@code Class.getCanonicalName()}
1014     * @return the class name of the class without the package name or an empty string. If the class is an inner class then
1015     *         value contains the outer class or classes and the separator is replaced to be {@code .} (dot) character.
1016     */
1017    public static String getShortClassName(String className) {
1018        if (StringUtils.isEmpty(className)) {
1019            return StringUtils.EMPTY;
1020        }
1021        final StringBuilder arrayPrefix = new StringBuilder();
1022        // Handle array encoding
1023        if (className.startsWith("[")) {
1024            while (className.charAt(0) == '[') {
1025                className = className.substring(1);
1026                arrayPrefix.append("[]");
1027            }
1028            // Strip Object type encoding
1029            if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
1030                className = className.substring(1, className.length() - 1);
1031            }
1032            if (REVERSE_ABBREVIATION_MAP.containsKey(className)) {
1033                className = REVERSE_ABBREVIATION_MAP.get(className);
1034            }
1035        }
1036        final int lastDotIdx = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
1037        final int innerIdx = className.indexOf(INNER_CLASS_SEPARATOR_CHAR, lastDotIdx == -1 ? 0 : lastDotIdx + 1);
1038        String out = className.substring(lastDotIdx + 1);
1039        if (innerIdx != -1) {
1040            out = out.replace(INNER_CLASS_SEPARATOR_CHAR, PACKAGE_SEPARATOR_CHAR);
1041        }
1042        return out + arrayPrefix;
1043    }
1044
1045    /**
1046     * Null-safe version of {@code cls.getSimpleName()}
1047     *
1048     * @param cls the class for which to get the simple name; may be null
1049     * @return the simple class name or the empty string in case the argument is {@code null}
1050     * @since 3.0
1051     * @see Class#getSimpleName()
1052     */
1053    public static String getSimpleName(final Class<?> cls) {
1054        return getSimpleName(cls, StringUtils.EMPTY);
1055    }
1056
1057    /**
1058     * Null-safe version of {@code cls.getSimpleName()}
1059     *
1060     * @param cls the class for which to get the simple name; may be null
1061     * @param valueIfNull the value to return if null
1062     * @return the simple class name or {@code valueIfNull} if the argument {@code cls} is {@code null}
1063     * @since 3.0
1064     * @see Class#getSimpleName()
1065     */
1066    public static String getSimpleName(final Class<?> cls, final String valueIfNull) {
1067        return cls == null ? valueIfNull : cls.getSimpleName();
1068    }
1069
1070    /**
1071     * Null-safe version of {@code object.getClass().getSimpleName()}
1072     *
1073     * <p>
1074     * It is to note that this method is overloaded and in case the argument {@code object} is a {@link Class} object then
1075     * the {@link #getSimpleName(Class)} will be invoked. If this is a significant possibility then the caller should check
1076     * this case and call {@code
1077     * getSimpleName(Class.class)} or just simply use the string literal {@code "Class"}, which is the result of the method
1078     * in that case.
1079     * </p>
1080     *
1081     * @param object the object for which to get the simple class name; may be null
1082     * @return the simple class name or the empty string in case the argument is {@code null}
1083     * @since 3.7
1084     * @see Class#getSimpleName()
1085     */
1086    public static String getSimpleName(final Object object) {
1087        return getSimpleName(object, StringUtils.EMPTY);
1088    }
1089
1090    /**
1091     * Null-safe version of {@code object.getClass().getSimpleName()}
1092     *
1093     * @param object the object for which to get the simple class name; may be null
1094     * @param valueIfNull the value to return if {@code object} is {@code null}
1095     * @return the simple class name or {@code valueIfNull} if the argument {@code object} is {@code null}
1096     * @since 3.0
1097     * @see Class#getSimpleName()
1098     */
1099    public static String getSimpleName(final Object object, final String valueIfNull) {
1100        return object == null ? valueIfNull : object.getClass().getSimpleName();
1101    }
1102
1103    /**
1104     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order,
1105     * excluding interfaces.
1106     *
1107     * @param type the type to get the class hierarchy from
1108     * @return Iterable an Iterable over the class hierarchy of the given class
1109     * @since 3.2
1110     */
1111    public static Iterable<Class<?>> hierarchy(final Class<?> type) {
1112        return hierarchy(type, Interfaces.EXCLUDE);
1113    }
1114
1115    /**
1116     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order.
1117     *
1118     * @param type the type to get the class hierarchy from
1119     * @param interfacesBehavior switch indicating whether to include or exclude interfaces
1120     * @return Iterable an Iterable over the class hierarchy of the given class
1121     * @since 3.2
1122     */
1123    public static Iterable<Class<?>> hierarchy(final Class<?> type, final Interfaces interfacesBehavior) {
1124        final Iterable<Class<?>> classes = () -> {
1125            final AtomicReference<Class<?>> next = new AtomicReference<>(type);
1126            return new Iterator<Class<?>>() {
1127
1128                @Override
1129                public boolean hasNext() {
1130                    return next.get() != null;
1131                }
1132
1133                @Override
1134                public Class<?> next() {
1135                    return next.getAndUpdate(Class::getSuperclass);
1136                }
1137
1138                @Override
1139                public void remove() {
1140                    throw new UnsupportedOperationException();
1141                }
1142
1143            };
1144        };
1145        if (interfacesBehavior != Interfaces.INCLUDE) {
1146            return classes;
1147        }
1148        return () -> {
1149            final Set<Class<?>> seenInterfaces = new HashSet<>();
1150            final Iterator<Class<?>> wrapped = classes.iterator();
1151
1152            return new Iterator<Class<?>>() {
1153                Iterator<Class<?>> interfaces = Collections.emptyIterator();
1154
1155                @Override
1156                public boolean hasNext() {
1157                    return interfaces.hasNext() || wrapped.hasNext();
1158                }
1159
1160                @Override
1161                public Class<?> next() {
1162                    if (interfaces.hasNext()) {
1163                        final Class<?> nextInterface = interfaces.next();
1164                        seenInterfaces.add(nextInterface);
1165                        return nextInterface;
1166                    }
1167                    final Class<?> nextSuperclass = wrapped.next();
1168                    final Set<Class<?>> currentInterfaces = new LinkedHashSet<>();
1169                    walkInterfaces(currentInterfaces, nextSuperclass);
1170                    interfaces = currentInterfaces.iterator();
1171                    return nextSuperclass;
1172                }
1173
1174                @Override
1175                public void remove() {
1176                    throw new UnsupportedOperationException();
1177                }
1178
1179                private void walkInterfaces(final Set<Class<?>> addTo, final Class<?> c) {
1180                    for (final Class<?> iface : c.getInterfaces()) {
1181                        if (!seenInterfaces.contains(iface)) {
1182                            addTo.add(iface);
1183                        }
1184                        walkInterfaces(addTo, iface);
1185                    }
1186                }
1187
1188            };
1189        };
1190    }
1191
1192    /**
1193     * Tests whether one {@link Class} can be assigned to a variable of another {@link Class}.
1194     *
1195     * <p>
1196     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
1197     * primitive classes and {@code null}s.
1198     * </p>
1199     *
1200     * <p>
1201     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
1202     * for these cases.
1203     * </p>
1204     *
1205     * <p>
1206     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
1207     * and the toClass is non-primitive.
1208     * </p>
1209     *
1210     * <p>
1211     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
1212     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
1213     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
1214     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
1215     * </p>
1216     *
1217     * <p>
1218     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
1219     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
1220     * VMs running Java versions &gt; 1.5.
1221     * </p>
1222     *
1223     * @param cls the Class to check, may be null
1224     * @param toClass the Class to try to assign into, returns false if null
1225     * @return {@code true} if assignment possible
1226     */
1227    public static boolean isAssignable(final Class<?> cls, final Class<?> toClass) {
1228        return isAssignable(cls, toClass, true);
1229    }
1230
1231    /**
1232     * Tests whether one {@link Class} can be assigned to a variable of another {@link Class}.
1233     *
1234     * <p>
1235     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
1236     * primitive classes and {@code null}s.
1237     * </p>
1238     *
1239     * <p>
1240     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
1241     * for these cases.
1242     * </p>
1243     *
1244     * <p>
1245     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
1246     * and the toClass is non-primitive.
1247     * </p>
1248     *
1249     * <p>
1250     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
1251     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
1252     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
1253     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
1254     * </p>
1255     *
1256     * @param cls the Class to check, may be null
1257     * @param toClass the Class to try to assign into, returns false if null
1258     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
1259     * @return {@code true} if assignment possible
1260     */
1261    public static boolean isAssignable(Class<?> cls, final Class<?> toClass, final boolean autoboxing) {
1262        if (toClass == null) {
1263            return false;
1264        }
1265        // have to check for null, as isAssignableFrom doesn't
1266        if (cls == null) {
1267            return !toClass.isPrimitive();
1268        }
1269        // autoboxing:
1270        if (autoboxing) {
1271            if (cls.isPrimitive() && !toClass.isPrimitive()) {
1272                cls = primitiveToWrapper(cls);
1273                if (cls == null) {
1274                    return false;
1275                }
1276            }
1277            if (toClass.isPrimitive() && !cls.isPrimitive()) {
1278                cls = wrapperToPrimitive(cls);
1279                if (cls == null) {
1280                    return false;
1281                }
1282            }
1283        }
1284        if (cls.equals(toClass)) {
1285            return true;
1286        }
1287        if (cls.isPrimitive()) {
1288            if (!toClass.isPrimitive()) {
1289                return false;
1290            }
1291            if (Integer.TYPE.equals(cls)) {
1292                return Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
1293            }
1294            if (Long.TYPE.equals(cls)) {
1295                return Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
1296            }
1297            if (Boolean.TYPE.equals(cls)) {
1298                return false;
1299            }
1300            if (Double.TYPE.equals(cls)) {
1301                return false;
1302            }
1303            if (Float.TYPE.equals(cls)) {
1304                return Double.TYPE.equals(toClass);
1305            }
1306            if (Character.TYPE.equals(cls)  || Short.TYPE.equals(cls)) {
1307                return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
1308            }
1309            if (Byte.TYPE.equals(cls)) {
1310                return Short.TYPE.equals(toClass) || Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
1311                    || Double.TYPE.equals(toClass);
1312            }
1313            // should never get here
1314            return false;
1315        }
1316        return toClass.isAssignableFrom(cls);
1317    }
1318
1319    /**
1320     * Tests whether an array of Classes can be assigned to another array of Classes.
1321     *
1322     * <p>
1323     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
1324     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
1325     * types (the second parameter).
1326     * </p>
1327     *
1328     * <p>
1329     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
1330     * primitive classes and {@code null}s.
1331     * </p>
1332     *
1333     * <p>
1334     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
1335     * returns the correct result for these cases.
1336     * </p>
1337     *
1338     * <p>
1339     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
1340     * and the toClass is non-primitive.
1341     * </p>
1342     *
1343     * <p>
1344     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
1345     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
1346     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
1347     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
1348     * </p>
1349     *
1350     * <p>
1351     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
1352     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
1353     * VMs running Java versions &gt; 1.5.
1354     * </p>
1355     *
1356     * @param classArray the array of Classes to check, may be {@code null}
1357     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
1358     * @return {@code true} if assignment possible
1359     */
1360    public static boolean isAssignable(final Class<?>[] classArray, final Class<?>... toClassArray) {
1361        return isAssignable(classArray, toClassArray, true);
1362    }
1363
1364    /**
1365     * Tests whether an array of Classes can be assigned to another array of Classes.
1366     *
1367     * <p>
1368     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
1369     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
1370     * types (the second parameter).
1371     * </p>
1372     *
1373     * <p>
1374     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
1375     * primitive classes and {@code null}s.
1376     * </p>
1377     *
1378     * <p>
1379     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
1380     * returns the correct result for these cases.
1381     * </p>
1382     *
1383     * <p>
1384     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
1385     * and the toClass is non-primitive.
1386     * </p>
1387     *
1388     * <p>
1389     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
1390     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
1391     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
1392     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
1393     * </p>
1394     *
1395     * @param classArray the array of Classes to check, may be {@code null}
1396     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
1397     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
1398     * @return {@code true} if assignment possible
1399     */
1400    public static boolean isAssignable(Class<?>[] classArray, Class<?>[] toClassArray, final boolean autoboxing) {
1401        if (!ArrayUtils.isSameLength(classArray, toClassArray)) {
1402            return false;
1403        }
1404        classArray = ArrayUtils.nullToEmpty(classArray);
1405        toClassArray = ArrayUtils.nullToEmpty(toClassArray);
1406        for (int i = 0; i < classArray.length; i++) {
1407            if (!isAssignable(classArray[i], toClassArray[i], autoboxing)) {
1408                return false;
1409            }
1410        }
1411        return true;
1412    }
1413
1414    /**
1415     * Tests whether the specified class an inner class or static nested class.
1416     *
1417     * @param cls the class to check, may be null
1418     * @return {@code true} if the class is an inner or static nested class, false if not or {@code null}
1419     */
1420    public static boolean isInnerClass(final Class<?> cls) {
1421        return cls != null && cls.getEnclosingClass() != null;
1422    }
1423
1424    /**
1425     * Tests whether the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
1426     * {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
1427     *
1428     * @param type The class to query or null.
1429     * @return true if the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
1430     *         {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
1431     * @since 3.1
1432     */
1433    public static boolean isPrimitiveOrWrapper(final Class<?> type) {
1434        return type != null && type.isPrimitive() || isPrimitiveWrapper(type);
1435    }
1436
1437    /**
1438     * Tests whether the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
1439     * {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
1440     *
1441     * @param type The class to query or null.
1442     * @return true if the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
1443     *         {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
1444     * @since 3.1
1445     */
1446    public static boolean isPrimitiveWrapper(final Class<?> type) {
1447        return WRAPPER_PRIMITIVE_MAP.containsKey(type);
1448    }
1449
1450    /**
1451     * Tests whether a {@link Class} is public.
1452     *
1453     * @param cls Class to test.
1454     * @return {@code true} if {@code cls} is public.
1455     * @since 3.13.0
1456     */
1457    public static boolean isPublic(final Class<?> cls) {
1458        return Modifier.isPublic(cls.getModifiers());
1459    }
1460
1461    /**
1462     * Converts the specified array of primitive Class objects to an array of its corresponding wrapper Class objects.
1463     *
1464     * @param classes the class array to convert, may be null or empty.
1465     * @return an array which contains for each given class, the wrapper class or the original class if class is not a primitive. {@code null} if null input.
1466     *         Empty array if an empty array passed in.
1467     * @since 2.1
1468     */
1469    public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {
1470        if (classes == null) {
1471            return null;
1472        }
1473        if (classes.length == 0) {
1474            return classes;
1475        }
1476        return ArrayUtils.setAll(new Class[classes.length], i -> primitiveToWrapper(classes[i]));
1477    }
1478
1479    /**
1480     * Converts the specified primitive Class object to its corresponding wrapper Class object.
1481     *
1482     * <p>
1483     * NOTE: From v2.2, this method handles {@code Void.TYPE}, returning {@code Void.TYPE}.
1484     * </p>
1485     *
1486     * @param cls the class to convert, may be null.
1487     * @return the wrapper class for {@code cls} or {@code cls} if {@code cls} is not a primitive. {@code null} if null input.
1488     * @since 2.1
1489     */
1490    public static Class<?> primitiveToWrapper(final Class<?> cls) {
1491        return cls != null && cls.isPrimitive() ? PRIMITIVE_WRAPPER_MAP.get(cls) : cls;
1492    }
1493
1494    /**
1495     * Converts a class name to a JLS style class name.
1496     *
1497     * @param className the class name
1498     * @return the converted name
1499     * @throws NullPointerException if the className is null
1500     */
1501    private static String toCanonicalName(final String className) {
1502        String canonicalName = StringUtils.deleteWhitespace(className);
1503        Objects.requireNonNull(canonicalName, "className");
1504        final String arrayMarker = "[]";
1505        if (canonicalName.endsWith(arrayMarker)) {
1506            final StringBuilder classNameBuffer = new StringBuilder();
1507            while (canonicalName.endsWith(arrayMarker)) {
1508                canonicalName = canonicalName.substring(0, canonicalName.length() - 2);
1509                classNameBuffer.append("[");
1510            }
1511            final String abbreviation = ABBREVIATION_MAP.get(canonicalName);
1512            if (abbreviation != null) {
1513                classNameBuffer.append(abbreviation);
1514            } else {
1515                classNameBuffer.append("L").append(canonicalName).append(";");
1516            }
1517            canonicalName = classNameBuffer.toString();
1518        }
1519        return canonicalName;
1520    }
1521
1522    /**
1523     * Converts an array of {@link Object} in to an array of {@link Class} objects. If any of these objects is null, a null element will be inserted into the
1524     * array.
1525     *
1526     * <p>
1527     * This method returns {@code null} for a {@code null} input array.
1528     * </p>
1529     *
1530     * @param array an {@link Object} array
1531     * @return a {@link Class} array, {@code null} if null array input
1532     * @since 2.4
1533     */
1534    public static Class<?>[] toClass(final Object... array) {
1535        if (array == null) {
1536            return null;
1537        }
1538        if (array.length == 0) {
1539            return ArrayUtils.EMPTY_CLASS_ARRAY;
1540        }
1541        return ArrayUtils.setAll(new Class[array.length], i -> array[i] == null ? null : array[i].getClass());
1542    }
1543
1544    /**
1545     * Decides if the part that was just copied to its destination location in the work array can be kept as it was copied
1546     * or must be abbreviated. It must be kept when the part is the last one, which is the simple name of the class. In this
1547     * case the {@code source} index, from where the characters are copied points one position after the last character,
1548     * a.k.a. {@code source ==
1549     * originalLength}
1550     *
1551     * <p>
1552     * If the part is not the last one then it can be kept unabridged if the number of the characters copied so far plus the
1553     * character that are to be copied is less than or equal to the desired length.
1554     * </p>
1555     *
1556     * @param runAheadTarget the target index (where the characters were copied to) pointing after the last character copied
1557     *        when the current part was copied
1558     * @param source the source index (where the characters were copied from) pointing after the last character copied when
1559     *        the current part was copied
1560     * @param originalLength the original length of the class full name, which is abbreviated
1561     * @param desiredLength the desired length of the abbreviated class name
1562     * @return {@code true} if it can be kept in its original length {@code false} if the current part has to be abbreviated
1563     *         and
1564     */
1565    private static boolean useFull(final int runAheadTarget, final int source, final int originalLength, final int desiredLength) {
1566        return source >= originalLength || runAheadTarget + originalLength - source <= desiredLength;
1567    }
1568
1569    /**
1570     * Converts the specified array of wrapper Class objects to an array of its corresponding primitive Class objects.
1571     *
1572     * <p>
1573     * This method invokes {@code wrapperToPrimitive()} for each element of the passed in array.
1574     * </p>
1575     *
1576     * @param classes the class array to convert, may be null or empty
1577     * @return an array which contains for each given class, the primitive class or <strong>null</strong> if the original class is not a wrapper class.
1578     *         {@code null} if null input. Empty array if an empty array passed in.
1579     * @see #wrapperToPrimitive(Class)
1580     * @since 2.4
1581     */
1582    public static Class<?>[] wrappersToPrimitives(final Class<?>... classes) {
1583        if (classes == null) {
1584            return null;
1585        }
1586        if (classes.length == 0) {
1587            return classes;
1588        }
1589        return ArrayUtils.setAll(new Class[classes.length], i -> wrapperToPrimitive(classes[i]));
1590    }
1591
1592    /**
1593     * Converts the specified wrapper class to its corresponding primitive class.
1594     *
1595     * <p>
1596     * This method is the counter part of {@code primitiveToWrapper()}. If the passed in class is a wrapper class for a
1597     * primitive type, this primitive type will be returned (e.g. {@code Integer.TYPE} for {@code Integer.class}). For other
1598     * classes, or if the parameter is <strong>null</strong>, the return value is <strong>null</strong>.
1599     * </p>
1600     *
1601     * @param cls the class to convert, may be <strong>null</strong>
1602     * @return the corresponding primitive type if {@code cls} is a wrapper class, <strong>null</strong> otherwise
1603     * @see #primitiveToWrapper(Class)
1604     * @since 2.4
1605     */
1606    public static Class<?> wrapperToPrimitive(final Class<?> cls) {
1607        return WRAPPER_PRIMITIVE_MAP.get(cls);
1608    }
1609
1610    /**
1611     * ClassUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
1612     * {@code ClassUtils.getShortClassName(cls)}.
1613     *
1614     * <p>
1615     * This constructor is public to permit tools that require a JavaBean instance to operate.
1616     * </p>
1617     *
1618     * @deprecated TODO Make private in 4.0.
1619     */
1620    @Deprecated
1621    public ClassUtils() {
1622        // empty
1623    }
1624
1625}