/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package org.apache.commons.lang3;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import org.apache.commons.lang3.mutable.MutableObject;

/**

 * <p>Operates on classes without using reflection.</p>

 *

 * <p>This class handles invalid {@code null} inputs as best it can.

 * Each method documents its behavior in more detail.</p>

 *

 * <p>The notion of a {@code canonical name} includes the human

 * readable name for the type, for example {@code int[]}. The

 * non-canonical method variants work with the JVM names, such as

 * {@code [I}. </p>

 *

 * @since 2.0

 */

public class ClassUtils {

    /**

     * Inclusivity literals for {@link #hierarchy(Class, Interfaces)}.

     * @since 3.2

     */

    public enum Interfaces {

        /** Includes interfaces. */

        INCLUDE,

        /** Excludes interfaces. */

        EXCLUDE

    }

    /**

     * The package separator character: {@code '.' == {@value}}.

     */

    public static final char PACKAGE_SEPARATOR_CHAR = '.';

    /**

     * The package separator String: {@code "."}.

     */

    public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);

    /**

     * The inner class separator character: {@code '$' == {@value}}.

     */

    public static final char INNER_CLASS_SEPARATOR_CHAR = '$';

    /**

     * The inner class separator String: {@code "$"}.

     */

    public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);

    /**

     * Maps names of primitives to their corresponding primitive {@code Class}es.

     */

    private static final Map<String, Class<?>> namePrimitiveMap = new HashMap<>();

    static {

         namePrimitiveMap.put("boolean", Boolean.TYPE);

         namePrimitiveMap.put("byte", Byte.TYPE);

         namePrimitiveMap.put("char", Character.TYPE);

         namePrimitiveMap.put("short", Short.TYPE);

         namePrimitiveMap.put("int", Integer.TYPE);

         namePrimitiveMap.put("long", Long.TYPE);

         namePrimitiveMap.put("double", Double.TYPE);

         namePrimitiveMap.put("float", Float.TYPE);

         namePrimitiveMap.put("void", Void.TYPE);

    }

    /**

     * Maps primitive {@code Class}es to their corresponding wrapper {@code Class}.

     */

    private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<>();

    static {

         primitiveWrapperMap.put(Boolean.TYPE, Boolean.class);

         primitiveWrapperMap.put(Byte.TYPE, Byte.class);

         primitiveWrapperMap.put(Character.TYPE, Character.class);

         primitiveWrapperMap.put(Short.TYPE, Short.class);

         primitiveWrapperMap.put(Integer.TYPE, Integer.class);

         primitiveWrapperMap.put(Long.TYPE, Long.class);

         primitiveWrapperMap.put(Double.TYPE, Double.class);

         primitiveWrapperMap.put(Float.TYPE, Float.class);

         primitiveWrapperMap.put(Void.TYPE, Void.TYPE);

    }

    /**

     * Maps wrapper {@code Class}es to their corresponding primitive types.

     */

    private static final Map<Class<?>, Class<?>> wrapperPrimitiveMap = new HashMap<>();

    static {

        for (final Map.Entry<Class<?>, Class<?>> entry : primitiveWrapperMap.entrySet()) {

            final Class<?> primitiveClass = entry.getKey();

            final Class<?> wrapperClass = entry.getValue();

            if (!primitiveClass.equals(wrapperClass)) {

                wrapperPrimitiveMap.put(wrapperClass, primitiveClass);

            }

        }

    }

    /**

     * Maps a primitive class name to its corresponding abbreviation used in array class names.

     */

    private static final Map<String, String> abbreviationMap;

    /**

     * Maps an abbreviation used in array class names to corresponding primitive class name.

     */

    private static final Map<String, String> reverseAbbreviationMap;

    // Feed abbreviation maps

    static {

        final Map<String, String> m = new HashMap<>();

        m.put("int", "I");

        m.put("boolean", "Z");

        m.put("float", "F");

        m.put("long", "J");

        m.put("short", "S");

        m.put("byte", "B");

        m.put("double", "D");

        m.put("char", "C");

        final Map<String, String> r = new HashMap<>();

        for (final Map.Entry<String, String> e : m.entrySet()) {

            r.put(e.getValue(), e.getKey());

        }

        abbreviationMap = Collections.unmodifiableMap(m);

        reverseAbbreviationMap = Collections.unmodifiableMap(r);

    }

    /**

     * <p>ClassUtils instances should NOT be constructed in standard programming.

     * Instead, the class should be used as

     * {@code ClassUtils.getShortClassName(cls)}.</p>

     *

     * <p>This constructor is public to permit tools that require a JavaBean

     * instance to operate.</p>

     */

    public ClassUtils() {

      super();

    }

    // Short class name

    // ----------------------------------------------------------------------

    /**

     * <p>Gets the class name of the {@code object} without the package name or names.</p>

     *

     * <p>The method looks up the class of the object and then converts the name of the class invoking

     * {@link #getShortClassName(Class)} (see relevant notes there).</p>

     *

     * @param object  the class to get the short name for, may be {@code null}

     * @param valueIfNull  the value to return if the object is {@code null}

     * @return the class name of the object without the package name, or {@code valueIfNull}

     *         if the argument {@code object} is {@code null}

     */

    public static String getShortClassName(final Object object, final String valueIfNull) {

        if (object == null) {

            return valueIfNull;

        }

        return getShortClassName(object.getClass());

    }

    /**

     * <p>Gets the class name minus the package name from a {@code Class}.</p>

     *

     * <p>This method simply gets the name using {@code Class.getName()} and then calls

     * {@link #getShortClassName(Class)}. See relevant notes there.</p>

     *

     * @param cls  the class to get the short name for.

     * @return the class name without the package name or an empty string. If the class

     *         is an inner class then the returned value will contain the outer class

     *         or classes separated with {@code .} (dot) character.

     */

    public static String getShortClassName(final Class<?> cls) {

        if (cls == null) {

            return StringUtils.EMPTY;

        }

        return getShortClassName(cls.getName());

    }

    /**

     * <p>Gets the class name minus the package name from a String.</p>

     *

     * <p>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 JDK method {@code Class.getName()} returns it, and not the usual way as we write it, for example in import

     * statements, or as it is formatted by {@code Class.getCanonicalName()}.</p>

     *

     * <p>The difference is is significant only in case of classes that are inner classes of some other

     * classes. In this case the separator between the outer and inner class (possibly on multiple hierarchy level) has

     * to be {@code $} (dollar sign) and not {@code .} (dot), as it is returned by {@code Class.getName()}</p>

     *

     * <p>Note that this method is called from the {@link #getShortClassName(Class)} method using the string

     * returned by {@code Class.getName()}.</p>

     *

     * <p>Note that this method differs from {@link #getSimpleName(Class)} in that this will

     * return, for example {@code "Map.Entry"} whilst the {@code java.lang.Class} variant will simply

     * return {@code "Entry"}. In this example the argument {@code className} is the string

     * {@code java.util.Map$Entry} (note the {@code $} sign.</p>

     *

     * @param className  the className to get the short name for. It has to be formatted as returned by

     *                   {@code Class.getName()} and not {@code Class.getCanonicalName()}

     * @return the class name of the class without the package name or an empty string. If the class is

     *         an inner class then value contains the outer class or classes and the separator is replaced

     *         to be {@code .} (dot) character.

     */

    public static String getShortClassName(String className) {

        if (StringUtils.isEmpty(className)) {

            return StringUtils.EMPTY;

        }

        final StringBuilder arrayPrefix = new StringBuilder();

        // Handle array encoding

        if (className.startsWith("[")) {

            while (className.charAt(0) == '[') {

                className = className.substring(1);

                arrayPrefix.append("[]");

            }

            // Strip Object type encoding

            if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {

                className = className.substring(1, className.length() - 1);

            }

            if (reverseAbbreviationMap.containsKey(className)) {

                className = reverseAbbreviationMap.get(className);

            }

        }

        final int lastDotIdx = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);

        final int innerIdx = className.indexOf(

                INNER_CLASS_SEPARATOR_CHAR, lastDotIdx == -1 ? 0 : lastDotIdx + 1);

        String out = className.substring(lastDotIdx + 1);

        if (innerIdx != -1) {

            out = out.replace(INNER_CLASS_SEPARATOR_CHAR, PACKAGE_SEPARATOR_CHAR);

        }

        return out + arrayPrefix;

    }

    /**

     * <p>Null-safe version of {@code cls.getSimpleName()}</p>

     *

     * @param cls the class for which to get the simple name; may be null

     * @return the simple class name or the empty string in case the argument is {@code null}

     * @since 3.0

     * @see Class#getSimpleName()

     */

    public static String getSimpleName(final Class<?> cls) {

        return getSimpleName(cls, StringUtils.EMPTY);

    }

    /**

     * <p>Null-safe version of {@code cls.getSimpleName()}</p>

     *

     * @param cls the class for which to get the simple name; may be null

     * @param valueIfNull  the value to return if null

     * @return the simple class name or {@code valueIfNull} if the

     *         argument {@code cls} is {@code null}

     * @since 3.0

     * @see Class#getSimpleName()

     */

    public static String getSimpleName(final Class<?> cls, final String valueIfNull) {

        return cls == null ? valueIfNull : cls.getSimpleName();

    }

    /**

     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>

     *

     * <p>It is to note that this method is overloaded and in case the argument {@code object} is a

     * {@code Class} object then the {@link #getSimpleName(Class)} will be invoked. If this is

     * a significant possibility then the caller should check this case and call {@code

     * getSimpleName(Class.class)} or just simply use the string literal {@code "Class"}, which

     * is the result of the method in that case.</p>

     *

     * @param object the object for which to get the simple class name; may be null

     * @return the simple class name or the empty string in case the argument is {@code null}

     * @since 3.7

     * @see Class#getSimpleName()

     */

    public static String getSimpleName(final Object object) {

        return getSimpleName(object, StringUtils.EMPTY);

    }

    /**

     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>

     *

     * @param object the object for which to get the simple class name; may be null

     * @param valueIfNull the value to return if {@code object} is {@code null}

     * @return the simple class name or {@code valueIfNull} if the

     *         argument {@code object} is {@code null}

     * @since 3.0

     * @see Class#getSimpleName()

     */

    public static String getSimpleName(final Object object, final String valueIfNull) {

        return object == null ? valueIfNull : object.getClass().getSimpleName();

    }

    /**

     * <p>Null-safe version of {@code cls.getName()}</p>

     *

     * @param cls the class for which to get the class name; may be null

     * @return the class name or the empty string in case the argument is {@code null}

     * @since 3.7

     * @see Class#getSimpleName()

     */

    public static String getName(final Class<?> cls) {

        return getName(cls, StringUtils.EMPTY);

    }

    /**

     * <p>Null-safe version of {@code cls.getName()}</p>

     *

     * @param cls the class for which to get the class name; may be null

     * @param valueIfNull the return value if the argument {@code cls} is {@code null}

     * @return the class name or {@code valueIfNull}

     * @since 3.7

     * @see Class#getName()

     */

    public static String getName(final Class<?> cls, final String valueIfNull) {

        return cls == null ? valueIfNull : cls.getName();

    }

    /**

     * <p>Null-safe version of {@code object.getClass().getName()}</p>

     *

     * @param object the object for which to get the class name; may be null

     * @return the class name or the empty String

     * @since 3.7

     * @see Class#getSimpleName()

     */

    public static String getName(final Object object) {

        return getName(object, StringUtils.EMPTY);

    }

    /**

     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>

     *

     * @param object the object for which to get the class name; may be null

     * @param valueIfNull the value to return if {@code object} is {@code null}

     * @return the class name or {@code valueIfNull}

     * @since 3.0

     * @see Class#getName()

     */

    public static String getName(final Object object, final String valueIfNull) {

        return object == null ? valueIfNull : object.getClass().getName();

    }

    // Package name

    // ----------------------------------------------------------------------

    /**

     * <p>Gets the package name of an {@code Object}.</p>

     *

     * @param object  the class to get the package name for, may be null

     * @param valueIfNull  the value to return if null

     * @return the package name of the object, or the null value

     */

    public static String getPackageName(final Object object, final String valueIfNull) {

        if (object == null) {

            return valueIfNull;

        }

        return getPackageName(object.getClass());

    }

    /**

     * <p>Gets the package name of a {@code Class}.</p>

     *

     * @param cls  the class to get the package name for, may be {@code null}.

     * @return the package name or an empty string

     */

    public static String getPackageName(final Class<?> cls) {

        if (cls == null) {

            return StringUtils.EMPTY;

        }

        return getPackageName(cls.getName());

    }

    /**

     * <p>Gets the package name from a {@code String}.</p>

     *

     * <p>The string passed in is assumed to be a class name - it is not checked.</p>

     * <p>If the class is unpackaged, return an empty string.</p>

     *

     * @param className  the className to get the package name for, may be {@code null}

     * @return the package name or an empty string

     */

    public static String getPackageName(String className) {

        if (StringUtils.isEmpty(className)) {

            return StringUtils.EMPTY;

        }

        // Strip array encoding

        while (className.charAt(0) == '[') {

            className = className.substring(1);

        }

        // Strip Object type encoding

        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {

            className = className.substring(1);

        }

        final int i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);

        if (i == -1) {

            return StringUtils.EMPTY;

        }

        return className.substring(0, i);

    }

    // Abbreviated name

    // ----------------------------------------------------------------------

    /**

     * <p>Gets the abbreviated name of a {@code Class}.</p>

     *

     * @param cls  the class to get the abbreviated name for, may be {@code null}

     * @param lengthHint  the desired length of the abbreviated name

     * @return the abbreviated name or an empty string

     * @throws IllegalArgumentException if len <= 0

     * @see #getAbbreviatedName(String, int)

     * @since 3.4

     */

    public static String getAbbreviatedName(final Class<?> cls, final int lengthHint) {

      if (cls == null) {

        return StringUtils.EMPTY;

      }

      return getAbbreviatedName(cls.getName(), lengthHint);

    }

    /**

     * <p>Gets the abbreviated class name from a {@code String}.</p>

     *

     * <p>The string passed in is assumed to be a class name - it is not checked.</p>

     *

     * <p>The abbreviation algorithm will shorten the class name, usually without

     * significant loss of meaning.</p>

     *

     * <p>The abbreviated class name will always include the complete package hierarchy.

     * If enough space is available, rightmost sub-packages will be displayed in full

     * length. The abbreviated package names will be shortened to a single character.</p>

     * <p>Only package names are shortened, the class simple name remains untouched. (See examples.)</p>

     * <p>The result will be longer than the desired length only if all the package names

     * shortened to a single character plus the class simple name with the separating dots

     * together are longer than the desired length. In other words, when the class name

     * cannot be shortened to the desired length.</p>

     * <p>If the class name can be shortened then

     * the final length will be at most {@code lengthHint} characters.</p>

     * <p>If the {@code lengthHint} is zero or negative then the method

     * throws exception. If you want to achieve the shortest possible version then

     * use {@code 1} as a {@code lengthHint}.</p>

     *

     * <table>

     * <caption>Examples</caption>

     * <tr><td>className</td><td>len</td><td>return</td></tr>

     * <tr><td>              null</td><td> 1</td><td>""</td></tr>

     * <tr><td>"java.lang.String"</td><td> 5</td><td>"j.l.String"</td></tr>

     * <tr><td>"java.lang.String"</td><td>15</td><td>"j.lang.String"</td></tr>

     * <tr><td>"java.lang.String"</td><td>30</td><td>"java.lang.String"</td></tr>

     * <tr><td>"org.apache.commons.lang3.ClassUtils"</td><td>18</td><td>"o.a.c.l.ClassUtils"</td></tr>

     * </table>

     *

     * @param className the className to get the abbreviated name for, may be {@code null}

     * @param lengthHint       the desired length of the abbreviated name

     * @return the abbreviated name or an empty string if the specified

     * class name is {@code null} or empty string. The abbreviated name may be

     * longer than the desired length if it cannot be abbreviated to the desired length.

     * @throws IllegalArgumentException if {@code len <= 0}

     * @since 3.4

     */

    public static String getAbbreviatedName(final String className, final int lengthHint) {

        if (lengthHint <= 0) {

            throw new IllegalArgumentException("len must be > 0");

        }

        if (className == null) {

            return StringUtils.EMPTY;

        }

        if (className.length() <= lengthHint) {

            return className;

        }

        final char[] abbreviated = className.toCharArray();

        int target = 0;

        int source = 0;

        while (source < abbreviated.length) {

            // copy the next part

            int runAheadTarget = target;

            while (source < abbreviated.length && abbreviated[source] != '.') {

                abbreviated[runAheadTarget++] = abbreviated[source++];

            }

            ++target;

            if (useFull(runAheadTarget, source, abbreviated.length, lengthHint)

                  || target > runAheadTarget) {

                target = runAheadTarget;

            }

            // copy the '.' unless it was the last part

            if (source < abbreviated.length) {

                abbreviated[target++] = abbreviated[source++];

            }

        }

        return new String(abbreviated, 0, target);

    }

    /**

     * <p>Decides if the part that was just copied to its destination

     * location in the work array can be kept as it was copied 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 case the {@code source}

     * index, from where the characters are copied points one position

     * after the last character, a.k.a. {@code source ==

     * originalLength}</p>

     *

     * <p>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 character that are to be copied is less than or equal to the

     * desired length.</p>

     *

     * @param runAheadTarget the target index (where the characters were

     *                       copied to) pointing after the last character

     *                       copied when the current part was copied

     * @param source         the source index (where the characters were

     *                       copied from) pointing after the last

     *                       character copied when the current part was

     *                       copied

     * @param originalLength the original length of the class full name,

     *                       which is abbreviated

     * @param desiredLength  the desired length of the abbreviated class

     *                       name

     * @return {@code true} if it can be kept in its original length

     * {@code false} if the current part has to be abbreviated and

     */

    private static boolean useFull(final int runAheadTarget,

                                   final int source,

                                   final int originalLength,

                                   final int desiredLength) {

        return source >= originalLength ||

            runAheadTarget + originalLength - source <= desiredLength;

    }

    // Superclasses/Superinterfaces

    // ----------------------------------------------------------------------

    /**

     * <p>Gets a {@code List} of superclasses for the given class.</p>

     *

     * @param cls  the class to look up, may be {@code null}

     * @return the {@code List} of superclasses in order going up from this one

     *  {@code null} if null input

     */

    public static List<Class<?>> getAllSuperclasses(final Class<?> cls) {

        if (cls == null) {

            return null;

        }

        final List<Class<?>> classes = new ArrayList<>();

        Class<?> superclass = cls.getSuperclass();

        while (superclass != null) {

            classes.add(superclass);

            superclass = superclass.getSuperclass();

        }

        return classes;

    }

    /**

     * <p>Gets a {@code List} of all interfaces implemented by the given

     * class and its superclasses.</p>

     *

     * <p>The order is determined by looking through each interface in turn as

     * declared in the source file and following its hierarchy up. Then each

     * superclass is considered in the same way. Later duplicates are ignored,

     * so the order is maintained.</p>

     *

     * @param cls  the class to look up, may be {@code null}

     * @return the {@code List} of interfaces in order,

     *  {@code null} if null input

     */

    public static List<Class<?>> getAllInterfaces(final Class<?> cls) {

        if (cls == null) {

            return null;

        }

        final LinkedHashSet<Class<?>> interfacesFound = new LinkedHashSet<>();

        getAllInterfaces(cls, interfacesFound);

        return new ArrayList<>(interfacesFound);

    }

    /**

     * Gets the interfaces for the specified class.

     *

     * @param cls  the class to look up, may be {@code null}

     * @param interfacesFound the {@code Set} of interfaces for the class

     */

    private static void getAllInterfaces(Class<?> cls, final HashSet<Class<?>> interfacesFound) {

        while (cls != null) {

            final Class<?>[] interfaces = cls.getInterfaces();

            for (final Class<?> i : interfaces) {

                if (interfacesFound.add(i)) {

                    getAllInterfaces(i, interfacesFound);

                }

            }

            cls = cls.getSuperclass();

         }

     }

    // Convert list

    // ----------------------------------------------------------------------

    /**

     * <p>Given a {@code List} of class names, this method converts them into classes.</p>

     *

     * <p>A new {@code List} is returned. If the class name cannot be found, {@code null}

     * is stored in the {@code List}. If the class name in the {@code List} is

     * {@code null}, {@code null} is stored in the output {@code List}.</p>

     *

     * @param classNames  the classNames to change

     * @return a {@code List} of Class objects corresponding to the class names,

     *  {@code null} if null input

     * @throws ClassCastException if classNames contains a non String entry

     */

    public static List<Class<?>> convertClassNamesToClasses(final List<String> classNames) {

        if (classNames == null) {

            return null;

        }

        final List<Class<?>> classes = new ArrayList<>(classNames.size());

        for (final String className : classNames) {

            try {

                classes.add(Class.forName(className));

            } catch (final Exception ex) {

                classes.add(null);

            }

        }

        return classes;

    }

    /**

     * <p>Given a {@code List} of {@code Class} objects, this method converts

     * them into class names.</p>

     *

     * <p>A new {@code List} is returned. {@code null} objects will be copied into

     * the returned list as {@code null}.</p>

     *

     * @param classes  the classes to change

     * @return a {@code List} of class names corresponding to the Class objects,

     *  {@code null} if null input

     * @throws ClassCastException if {@code classes} contains a non-{@code Class} entry

     */

    public static List<String> convertClassesToClassNames(final List<Class<?>> classes) {

        if (classes == null) {

            return null;

        }

        final List<String> classNames = new ArrayList<>(classes.size());

        for (final Class<?> cls : classes) {

            if (cls == null) {

                classNames.add(null);

            } else {

                classNames.add(cls.getName());

            }

        }

        return classNames;

    }

    // Is assignable

    // ----------------------------------------------------------------------

    /**

     * <p>Checks if an array of Classes can be assigned to another array of Classes.</p>

     *

     * <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each

     * Class pair in the input arrays. It can be used to check if a set of arguments

     * (the first parameter) are suitably compatible with a set of method parameter types

     * (the second parameter).</p>

     *

     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this

     * method takes into account widenings of primitive classes and

     * {@code null}s.</p>

     *

     * <p>Primitive widenings allow an int to be assigned to a {@code long},

     * {@code float} or {@code double}. This method returns the correct

     * result for these cases.</p>

     *

     * <p>{@code Null} may be assigned to any reference type. This method will

     * return {@code true} if {@code null} is passed in and the toClass is

     * non-primitive.</p>

     *

     * <p>Specifically, this method tests whether the type represented by the

     * specified {@code Class} parameter can be converted to the type

     * represented by this {@code Class} object via an identity conversion

     * widening primitive or widening reference conversion. See

     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,

     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>

     *

     * <p><strong>Since Lang 3.0,</strong> this method will default behavior for

     * calculating assignability between primitive and wrapper types <em>corresponding

     * to the running Java version</em>; i.e. autoboxing will be the default

     * behavior in VMs running Java versions &gt; 1.5.</p>

     *

     * @param classArray  the array of Classes to check, may be {@code null}

     * @param toClassArray  the array of Classes to try to assign into, may be {@code null}

     * @return {@code true} if assignment possible

     */

    public static boolean isAssignable(final Class<?>[] classArray, final Class<?>... toClassArray) {

        return isAssignable(classArray, toClassArray, true);

    }

    /**

     * <p>Checks if an array of Classes can be assigned to another array of Classes.</p>

     *

     * <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each

     * Class pair in the input arrays. It can be used to check if a set of arguments

     * (the first parameter) are suitably compatible with a set of method parameter types

     * (the second parameter).</p>

     *

     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this

     * method takes into account widenings of primitive classes and

     * {@code null}s.</p>

     *

     * <p>Primitive widenings allow an int to be assigned to a {@code long},

     * {@code float} or {@code double}. This method returns the correct

     * result for these cases.</p>

     *

     * <p>{@code Null} may be assigned to any reference type. This method will

     * return {@code true} if {@code null} is passed in and the toClass is

     * non-primitive.</p>

     *

     * <p>Specifically, this method tests whether the type represented by the

     * specified {@code Class} parameter can be converted to the type

     * represented by this {@code Class} object via an identity conversion

     * widening primitive or widening reference conversion. See

     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,

     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>

     *

     * @param classArray  the array of Classes to check, may be {@code null}

     * @param toClassArray  the array of Classes to try to assign into, may be {@code null}

     * @param autoboxing  whether to use implicit autoboxing/unboxing between primitives and wrappers

     * @return {@code true} if assignment possible

     */

    public static boolean isAssignable(Class<?>[] classArray, Class<?>[] toClassArray, final boolean autoboxing) {

        if (!ArrayUtils.isSameLength(classArray, toClassArray)) {

            return false;

        }

        if (classArray == null) {

            classArray = ArrayUtils.EMPTY_CLASS_ARRAY;

        }

        if (toClassArray == null) {

            toClassArray = ArrayUtils.EMPTY_CLASS_ARRAY;

        }

        for (int i = 0; i < classArray.length; i++) {

            if (!isAssignable(classArray[i], toClassArray[i], autoboxing)) {

                return false;

            }

        }

        return true;

    }

    /**

     * Returns whether the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},

     * {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).

     *

     * @param type

     *            The class to query or null.

     * @return true if the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},

     *         {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).

     * @since 3.1

     */

    public static boolean isPrimitiveOrWrapper(final Class<?> type) {

        if (type == null) {

            return false;

        }

        return type.isPrimitive() || isPrimitiveWrapper(type);

    }

    /**

     * Returns whether the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character}, {@link Short},

     * {@link Integer}, {@link Long}, {@link Double}, {@link Float}).

     *

     * @param type

     *            The class to query or null.

     * @return true if the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character}, {@link Short},

     *         {@link Integer}, {@link Long}, {@link Double}, {@link Float}).

     * @since 3.1

     */

    public static boolean isPrimitiveWrapper(final Class<?> type) {

        return wrapperPrimitiveMap.containsKey(type);

    }

    /**

     * <p>Checks if one {@code Class} can be assigned to a variable of

     * another {@code Class}.</p>

     *

     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method,

     * this method takes into account widenings of primitive classes and

     * {@code null}s.</p>

     *

     * <p>Primitive widenings allow an int to be assigned to a long, float or

     * double. This method returns the correct result for these cases.</p>

     *

     * <p>{@code Null} may be assigned to any reference type. This method

     * will return {@code true} if {@code null} is passed in and the

     * toClass is non-primitive.</p>

     *

     * <p>Specifically, this method tests whether the type represented by the

     * specified {@code Class} parameter can be converted to the type

     * represented by this {@code Class} object via an identity conversion

     * widening primitive or widening reference conversion. See

     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,

     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>

     *

     * <p><strong>Since Lang 3.0,</strong> this method will default behavior for

     * calculating assignability between primitive and wrapper types <em>corresponding

     * to the running Java version</em>; i.e. autoboxing will be the default

     * behavior in VMs running Java versions &gt; 1.5.</p>

     *

     * @param cls  the Class to check, may be null

     * @param toClass  the Class to try to assign into, returns false if null

     * @return {@code true} if assignment possible

     */

    public static boolean isAssignable(final Class<?> cls, final Class<?> toClass) {

        return isAssignable(cls, toClass, true);

    }

    /**

     * <p>Checks if one {@code Class} can be assigned to a variable of

     * another {@code Class}.</p>

     *

     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method,

     * this method takes into account widenings of primitive classes and

     * {@code null}s.</p>

     *

     * <p>Primitive widenings allow an int to be assigned to a long, float or

     * double. This method returns the correct result for these cases.</p>

     *

     * <p>{@code Null} may be assigned to any reference type. This method

     * will return {@code true} if {@code null} is passed in and the

     * toClass is non-primitive.</p>

     *

     * <p>Specifically, this method tests whether the type represented by the

     * specified {@code Class} parameter can be converted to the type

     * represented by this {@code Class} object via an identity conversion

     * widening primitive or widening reference conversion. See

     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,

     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>

     *

     * @param cls  the Class to check, may be null

     * @param toClass  the Class to try to assign into, returns false if null

     * @param autoboxing  whether to use implicit autoboxing/unboxing between primitives and wrappers

     * @return {@code true} if assignment possible

     */

    public static boolean isAssignable(Class<?> cls, final Class<?> toClass, final boolean autoboxing) {

        if (toClass == null) {

            return false;

        }

        // have to check for null, as isAssignableFrom doesn't

        if (cls == null) {

            return !toClass.isPrimitive();

        }

        //autoboxing:

        if (autoboxing) {

            if (cls.isPrimitive() && !toClass.isPrimitive()) {

                cls = primitiveToWrapper(cls);

                if (cls == null) {

                    return false;

                }

            }

            if (toClass.isPrimitive() && !cls.isPrimitive()) {

                cls = wrapperToPrimitive(cls);

                if (cls == null) {

                    return false;

                }

            }

        }

        if (cls.equals(toClass)) {

            return true;

        }

        if (cls.isPrimitive()) {

            if (!toClass.isPrimitive()) {

                return false;

            }

            if (Integer.TYPE.equals(cls)) {

                return Long.TYPE.equals(toClass)

                    || Float.TYPE.equals(toClass)

                    || Double.TYPE.equals(toClass);

            }

            if (Long.TYPE.equals(cls)) {

                return Float.TYPE.equals(toClass)

                    || Double.TYPE.equals(toClass);

            }

            if (Boolean.TYPE.equals(cls)) {

                return false;

            }

            if (Double.TYPE.equals(cls)) {

                return false;

            }

            if (Float.TYPE.equals(cls)) {

                return Double.TYPE.equals(toClass);

            }

            if (Character.TYPE.equals(cls)) {

                return Integer.TYPE.equals(toClass)

                    || Long.TYPE.equals(toClass)

                    || Float.TYPE.equals(toClass)

                    || Double.TYPE.equals(toClass);

            }

            if (Short.TYPE.equals(cls)) {

                return Integer.TYPE.equals(toClass)

                    || Long.TYPE.equals(toClass)

                    || Float.TYPE.equals(toClass)

                    || Double.TYPE.equals(toClass);

            }

            if (Byte.TYPE.equals(cls)) {

                return Short.TYPE.equals(toClass)

                    || Integer.TYPE.equals(toClass)

                    || Long.TYPE.equals(toClass)

                    || Float.TYPE.equals(toClass)

                    || Double.TYPE.equals(toClass);

            }

            // should never get here

            return false;

        }

        return toClass.isAssignableFrom(cls);

    }

    /**

     * <p>Converts the specified primitive Class object to its corresponding

     * wrapper Class object.</p>

     *

     * <p>NOTE: From v2.2, this method handles {@code Void.TYPE},

     * returning {@code Void.TYPE}.</p>

     *

     * @param cls  the class to convert, may be null

     * @return the wrapper class for {@code cls} or {@code cls} if

     * {@code cls} is not a primitive. {@code null} if null input.

     * @since 2.1

     */

    public static Class<?> primitiveToWrapper(final Class<?> cls) {

        Class<?> convertedClass = cls;

        if (cls != null && cls.isPrimitive()) {

            convertedClass = primitiveWrapperMap.get(cls);

        }

        return convertedClass;

    }

    /**

     * <p>Converts the specified array of primitive Class objects to an array of

     * its corresponding wrapper Class objects.</p>

     *

     * @param classes  the class array to convert, may be null or empty

     * @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.

     * Empty array if an empty array passed in.

     * @since 2.1

     */

    public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {

        if (classes == null) {

            return null;

        }

        if (classes.length == 0) {

            return classes;

        }

        final Class<?>[] convertedClasses = new Class[classes.length];

        for (int i = 0; i < classes.length; i++) {

            convertedClasses[i] = primitiveToWrapper(classes[i]);

        }

        return convertedClasses;

    }

    /**

     * <p>Converts the specified wrapper class to its corresponding primitive

     * class.</p>

     *

     * <p>This method is the counter part of {@code primitiveToWrapper()}.

     * If the passed in class is a wrapper class for a primitive type, this

     * primitive type will be returned (e.g. {@code Integer.TYPE} for

     * {@code Integer.class}). For other classes, or if the parameter is

     * <b>null</b>, the return value is <b>null</b>.</p>

     *

     * @param cls the class to convert, may be <b>null</b>

     * @return the corresponding primitive type if {@code cls} is a

     * wrapper class, <b>null</b> otherwise

     * @see #primitiveToWrapper(Class)

     * @since 2.4

     */

    public static Class<?> wrapperToPrimitive(final Class<?> cls) {

        return wrapperPrimitiveMap.get(cls);

    }

    /**

     * <p>Converts the specified array of wrapper Class objects to an array of

     * its corresponding primitive Class objects.</p>

     *

     * <p>This method invokes {@code wrapperToPrimitive()} for each element

     * of the passed in array.</p>

     *

     * @param classes  the class array to convert, may be null or empty

     * @return an array which contains for each given class, the primitive class or

     * <b>null</b> if the original class is not a wrapper class. {@code null} if null input.

     * Empty array if an empty array passed in.

     * @see #wrapperToPrimitive(Class)

     * @since 2.4

     */

    public static Class<?>[] wrappersToPrimitives(final Class<?>... classes) {

        if (classes == null) {

            return null;

        }

        if (classes.length == 0) {

            return classes;

        }

        final Class<?>[] convertedClasses = new Class[classes.length];

        for (int i = 0; i < classes.length; i++) {

            convertedClasses[i] = wrapperToPrimitive(classes[i]);

        }

        return convertedClasses;

    }

    // Inner class

    // ----------------------------------------------------------------------

    /**

     * <p>Is the specified class an inner class or static nested class.</p>

     *

     * @param cls  the class to check, may be null

     * @return {@code true} if the class is an inner or static nested class,

     *  false if not or {@code null}

     */

    public static boolean isInnerClass(final Class<?> cls) {

        return cls != null && cls.getEnclosingClass() != null;

    }

    // Class loading

    // ----------------------------------------------------------------------

    /**

     * Returns the class represented by {@code className} using the

     * {@code classLoader}.  This implementation supports the syntaxes

     * "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",

     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".

     *

     * @param classLoader  the class loader to use to load the class

     * @param className  the class name

     * @param initialize  whether the class must be initialized

     * @return the class represented by {@code className} using the {@code classLoader}

     * @throws ClassNotFoundException if the class is not found

     */

    public static Class<?> getClass(

            final ClassLoader classLoader, final String className, final boolean initialize) throws ClassNotFoundException {

        try {

            Class<?> clazz;

            if (namePrimitiveMap.containsKey(className)) {

                clazz = namePrimitiveMap.get(className);

            } else {

                clazz = Class.forName(toCanonicalName(className), initialize, classLoader);

            }

            return clazz;

        } catch (final ClassNotFoundException ex) {

            // allow path separators (.) as inner class name separators

            final int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);

            if (lastDotIndex != -1) {

                try {

                    return getClass(classLoader, className.substring(0, lastDotIndex) +

                            INNER_CLASS_SEPARATOR_CHAR + className.substring(lastDotIndex + 1),

                            initialize);

                } catch (final ClassNotFoundException ex2) { // NOPMD

                    // ignore exception

                }

            }

            throw ex;

        }

    }

    /**

     * Returns the (initialized) class represented by {@code className}

     * using the {@code classLoader}.  This implementation supports

     * the syntaxes "{@code java.util.Map.Entry[]}",

     * "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}",

     * and "{@code [Ljava.util.Map$Entry;}".

     *

     * @param classLoader  the class loader to use to load the class

     * @param className  the class name

     * @return the class represented by {@code className} using the {@code classLoader}

     * @throws ClassNotFoundException if the class is not found

     */

    public static Class<?> getClass(final ClassLoader classLoader, final String className) throws ClassNotFoundException {

        return getClass(classLoader, className, true);

    }

    /**

     * Returns the (initialized) class represented by {@code className}

     * using the current thread's context class loader. This implementation

     * supports the syntaxes "{@code java.util.Map.Entry[]}",

     * "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}",

     * and "{@code [Ljava.util.Map$Entry;}".

     *

     * @param className  the class name

     * @return the class represented by {@code className} using the current thread's context class loader

     * @throws ClassNotFoundException if the class is not found

     */

    public static Class<?> getClass(final String className) throws ClassNotFoundException {

        return getClass(className, true);

    }

    /**

     * Returns the class represented by {@code className} using the

     * current thread's context class loader. This implementation supports the

     * syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",

     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".

     *

     * @param className  the class name

     * @param initialize  whether the class must be initialized

     * @return the class represented by {@code className} using the current thread's context class loader

     * @throws ClassNotFoundException if the class is not found

     */

    public static Class<?> getClass(final String className, final boolean initialize) throws ClassNotFoundException {

        final ClassLoader contextCL = Thread.currentThread().getContextClassLoader();

        final ClassLoader loader = contextCL == null ? ClassUtils.class.getClassLoader() : contextCL;

        return getClass(loader, className, initialize);

    }

    // Public method

    // ----------------------------------------------------------------------

    /**

     * <p>Returns the desired Method much like {@code Class.getMethod}, however

     * it ensures that the returned Method is from a public class or interface and not

     * from an anonymous inner class. This means that the Method is invokable and

     * doesn't fall foul of Java bug

     * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4071957">4071957</a>).</p>

     *

     *  <pre>

     *  <code>Set set = Collections.unmodifiableSet(...);

     *  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);

     *  Object result = method.invoke(set, new Object[]);</code>

     *  </pre>

     *

     * @param cls  the class to check, not null

     * @param methodName  the name of the method

     * @param parameterTypes  the list of parameters

     * @return the method

     * @throws NullPointerException if the class is null

     * @throws SecurityException if a security violation occurred

     * @throws NoSuchMethodException if the method is not found in the given class

     *  or if the method doesn't conform with the requirements

     */

    public static Method getPublicMethod(final Class<?> cls, final String methodName, final Class<?>... parameterTypes)

            throws NoSuchMethodException {

        final Method declaredMethod = cls.getMethod(methodName, parameterTypes);

        if (Modifier.isPublic(declaredMethod.getDeclaringClass().getModifiers())) {

            return declaredMethod;

        }

        final List<Class<?>> candidateClasses = new ArrayList<>();

        candidateClasses.addAll(getAllInterfaces(cls));

        candidateClasses.addAll(getAllSuperclasses(cls));

        for (final Class<?> candidateClass : candidateClasses) {

            if (!Modifier.isPublic(candidateClass.getModifiers())) {

                continue;

            }

            Method candidateMethod;

            try {

                candidateMethod = candidateClass.getMethod(methodName, parameterTypes);

            } catch (final NoSuchMethodException ex) {

                continue;

            }

            if (Modifier.isPublic(candidateMethod.getDeclaringClass().getModifiers())) {

                return candidateMethod;

            }

        }

        throw new NoSuchMethodException("Can't find a public method for " +

                methodName + " " + ArrayUtils.toString(parameterTypes));

    }

    // ----------------------------------------------------------------------

    /**

     * Converts a class name to a JLS style class name.

     *

     * @param className  the class name

     * @return the converted name

     */

    private static String toCanonicalName(String className) {

        className = StringUtils.deleteWhitespace(className);

        Validate.notNull(className, "className must not be null.");

        if (className.endsWith("[]")) {

            final StringBuilder classNameBuffer = new StringBuilder();

            while (className.endsWith("[]")) {

                className = className.substring(0, className.length() - 2);

                classNameBuffer.append("[");

            }

            final String abbreviation = abbreviationMap.get(className);

            if (abbreviation != null) {

                classNameBuffer.append(abbreviation);

            } else {

                classNameBuffer.append("L").append(className).append(";");

            }

            className = classNameBuffer.toString();

        }

        return className;

    }

    /**

     * <p>Converts an array of {@code Object} in to an array of {@code Class} objects.

     * If any of these objects is null, a null element will be inserted into the array.</p>

     *

     * <p>This method returns {@code null} for a {@code null} input array.</p>

     *

     * @param array an {@code Object} array

     * @return a {@code Class} array, {@code null} if null array input

     * @since 2.4

     */

    public static Class<?>[] toClass(final Object... array) {

        if (array == null) {

            return null;

        } else if (array.length == 0) {

            return ArrayUtils.EMPTY_CLASS_ARRAY;

        }

        final Class<?>[] classes = new Class[array.length];

        for (int i = 0; i < array.length; i++) {

            classes[i] = array[i] == null ? null : array[i].getClass();

        }