- /* ====================================================================
- * The Apache Software License, Version 1.1
- *
- * Copyright (c) 2002-2003 The Apache Software Foundation. All rights
- * reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. The end-user documentation included with the redistribution, if
- * any, must include the following acknowledgement:
- * "This product includes software developed by the
- * Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgement may appear in the software itself,
- * if and wherever such third-party acknowledgements normally appear.
- *
- * 4. The names "The Jakarta Project", "Commons", and "Apache Software
- * Foundation" must not be used to endorse or promote products derived
- * from this software without prior written permission. For written
- * permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache"
- * nor may "Apache" appear in their names without prior written
- * permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- */
- package org.apache.commons.lang;
-
- import java.util.ArrayList;
- import java.util.Iterator;
- import java.util.List;
- /**
- * <p>Operates on classes without using reflection.</p>
- *
- * <p>This class handles invalid <code>null</code> inputs as best it can.
- * Each method documents its behaviour in more detail.</p>
- *
- * @author Stephen Colebourne
- * @author Gary Gregory
- * @since 2.0
- * @version $Id: ClassUtils.java,v 1.21 2003/08/22 17:25:33 ggregory Exp $
- */
- public class ClassUtils {
-
- /**
- * <p>The package separator character: <code>.</code>.</p>
- */
- public static final char PACKAGE_SEPARATOR_CHAR = '.';
-
- /**
- * <p>The package separator String: <code>.</code>.</p>
- */
- public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);
-
- /**
- * <p>The inner class separator character: <code>$</code>.</p>
- */
- public static final char INNER_CLASS_SEPARATOR_CHAR = '$';
-
- /**
- * <p>The inner class separator String: <code>$</code>.</p>
- */
- public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);
-
- /**
- * <p>ClassUtils instances should NOT be constructed in standard programming.
- * Instead, the class should be used as
- * <code>ClassUtils.getShortClassName(cls)</code>.</p>
- *
- * <p>This constructor is public to permit tools that require a JavaBean
- * instance to operate.</p>
- */
- public ClassUtils() {
- }
-
- // Short class name
- // ----------------------------------------------------------------------
- /**
- * <p>Gets the class name minus the package name for an <code>Object</code>.</p>
- *
- * @param object the class to get the short name for, may be null
- * @param valueIfNull the value to return if null
- * @return the class name of the object without the package name, or the null value
- */
- public static String getShortClassName(Object object, String valueIfNull) {
- if (object == null) {
- return valueIfNull;
- }
- return getShortClassName(object.getClass().getName());
- }
-
- /**
- * <p>Gets the class name minus the package name from a <code>Class</code>.</p>
- *
- * @param cls the class to get the short name for, must not be
- * <code>null</code>
- * @return the class name without the package name
- * @throws IllegalArgumentException if the class is <code>null</code>
- */
- public static String getShortClassName(Class cls) {
- if (cls == null) {
- throw new IllegalArgumentException("The class must not be null");
- }
- 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.</p>
- *
- * @param className the className to get the short name for,
- * must not be empty or <code>null</code>
- * @return the class name of the class without the package name
- * @throws IllegalArgumentException if the className is empty
- */
- public static String getShortClassName(String className) {
- if (StringUtils.isEmpty(className)) {
- throw new IllegalArgumentException("The class name must not be empty");
- }
- char[] chars = className.toCharArray();
- int lastDot = 0;
- for (int i = 0; i < chars.length; i++) {
- if (chars[i] == PACKAGE_SEPARATOR_CHAR) {
- lastDot = i + 1;
- } else if (chars[i] == INNER_CLASS_SEPARATOR_CHAR) { // handle inner classes
- chars[i] = PACKAGE_SEPARATOR_CHAR;
- }
- }
- return new String(chars, lastDot, chars.length - lastDot);
- }
-
- // Package name
- // ----------------------------------------------------------------------
- /**
- * <p>Gets the package name of an <code>Object</code>.</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(Object object, String valueIfNull) {
- if (object == null) {
- return valueIfNull;
- }
- return getPackageName(object.getClass().getName());
- }
-
- /**
- * <p>Gets the package name of a <code>Class</code>.</p>
- *
- * @param cls the class to get the package name for,
- * must not be <code>null</code>
- * @return the package name
- * @throws IllegalArgumentException if the class is <code>null</code>
- */
- public static String getPackageName(Class cls) {
- if (cls == null) {
- throw new IllegalArgumentException("The class must not be null");
- }
- return getPackageName(cls.getName());
- }
-
- /**
- * <p>Gets the package name from a <code>String</code>.</p>
- *
- * <p>The string passed in is assumed to be a class name - it is not checked.</p>
- *
- * @param className the className to get the package name for,
- * must not be empty or <code>null</code>
- * @return the package name
- * @throws IllegalArgumentException if the className is empty
- */
- public static String getPackageName(String className) {
- if (StringUtils.isEmpty(className)) {
- throw new IllegalArgumentException("The class name must not be empty");
- }
- int i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
- if (i == -1) {
- return "";
- }
- return className.substring(0, i);
- }
-
- // Superclasses/Superinterfaces
- // ----------------------------------------------------------------------
- /**
- * <p>Gets a <code>List</code> of superclasses for the given class.</p>
- *
- * @param cls the class to look up, must not be <code>null</code>
- * @return the <code>List</code> of superclasses in order going up from this one
- * <code>null</code> if null input
- */
- public static List getAllSuperclasses(Class cls) {
- if (cls == null) {
- return null;
- }
- List classes = new ArrayList();
- Class superclass = cls.getSuperclass();
- while (superclass != null) {
- classes.add(superclass);
- superclass = superclass.getSuperclass();
- }
- return classes;
- }
-
- /**
- * <p>Gets a <code>List</code> 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 hieracrchy 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, must not be <code>null</code>
- * @return the <code>List</code> of interfaces in order,
- * <code>null</code> if null input
- */
- public static List getAllInterfaces(Class cls) {
- if (cls == null) {
- return null;
- }
- List list = new ArrayList();
- while (cls != null) {
- Class[] interfaces = cls.getInterfaces();
- for (int i = 0; i < interfaces.length; i++) {
- if (list.contains(interfaces[i]) == false) {
- list.add(interfaces[i]);
- }
- List superInterfaces = getAllInterfaces(interfaces[i]);
- for (Iterator it = superInterfaces.iterator(); it.hasNext();) {
- Class intface = (Class) it.next();
- if (list.contains(intface) == false) {
- list.add(intface);
- }
- }
- }
- cls = cls.getSuperclass();
- }
- return list;
- }
-
- // /**
- // * <p>Gets a <code>List</code> of subclasses of the specified class.</p>
- // *
- // * <p>This method searches the classpath to find all the subclasses
- // * of a particular class available. No classes are loaded, the
- // * returned list contains class names, not classes.</p>
- // *
- // * @param cls the class to find subclasses for
- // * @return the <code>List</code> of subclass String class names
- // * @throws IllegalArgumentException if the class is <code>null</code>
- // */
- // public static List getAllSubclassNames(Class cls) {
- // if (cls == null) {
- // throw new IllegalArgumentException("The class must not be null");
- // }
- // // TODO Use JavaWorld tip for searching the classpath
- // return null;
- // }
-
- // /**
- // * <p>Gets a <code>List</code> of subclasses of the specified class.</p>
- // *
- // * <p>This method searches the classpath to find all the subclasses
- // * of a particular class available.</p>
- // *
- // * @param cls the class to find subclasses for
- // * @return the <code>List</code> of subclasses
- // * @throws IllegalArgumentException if the class is <code>null</code>
- // */
- // public static List getAllSubclasses(Class cls) {
- // List names = getAllSubclassNames(cls);
- // return convertClassNamesToClasses(names);
- // }
-
- // /**
- // * <p>Gets a <code>List</code> of implementations of the specified interface.</p>
- // *
- // * <p>This method searches the classpath to find all the implementations
- // * of a particular interface available. No classes are loaded, the
- // * returned list contains class names, not classes.</p>
- // *
- // * @param cls the class to find sub classes for
- // * @return the <code>List</code> of implementation String class names
- // * @throws IllegalArgumentException if the class is <code>null</code>
- // */
- // public static List getAllImplementationClassNames(Class cls) {
- // if (cls == null) {
- // throw new IllegalArgumentException("The class must not be null");
- // }
- // // TODO Use JavaWorld tip for searching the classpath
- // return null;
- // }
-
- // Convert list
- // ----------------------------------------------------------------------
- /**
- * <p>Given a <code>List</code> of class names, this method converts them into classes.</p>
- *
- * <p>A new <code>List</code> is returned. If the class name cannot be found, <code>null</code>
- * is stored in the <code>List</code>. If the class name in the <code>List</code> is
- * <code>null</code>, <code>null</code> is stored in the output <code>List</code>.</p>
- *
- * @param classNames the classNames to change
- * @return a <code>List</code> of Class objects corresponding to the class names,
- * <code>null</code> if null input
- * @throws ClassCastException if classNames contains a non String entry
- */
- public static List convertClassNamesToClasses(List classNames) {
- if (classNames == null) {
- return null;
- }
- List classes = new ArrayList(classNames.size());
- for (Iterator it = classNames.iterator(); it.hasNext();) {
- String className = (String) it.next();
- try {
- classes.add(Class.forName(className));
- } catch (Exception ex) {
- classes.add(null);
- }
- }
- return classes;
- }
-
- /**
- * <p>Given a <code>List</code> of <code>Class</code> objects, this method converts
- * them into class names.</p>
- *
- * <p>A new <code>List</code> is returned. <code>null</code> objects will be copied into
- * the returned list as <code>null</code>.</p>
- *
- * @param classes the classes to change
- * @return a <code>List</code> of Class objects corresponding to the class names,
- * <code>null</code> if null input
- * @throws ClassCastException if classNames contains a non Class or null entry
- */
- public static List convertClassesToClassNames(List classes) {
- if (classes == null) {
- return null;
- }
- List classNames = new ArrayList(classes.size());
- for (Iterator it = classes.iterator(); it.hasNext();) {
- Class cls = (Class) it.next();
- 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 compatable 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</code>s.</p>
- *
- * <p>Primitive widenings allow an int to be assigned to a <code>long</code>,
- * <code>float</code> or <code>double</code>. This method returns the correct
- * result for these cases.</p>
- *
- * <p><code>Null</code> may be assigned to any reference type. This method will
- * return <code>true</code> if <code>null</code> is passed in and the toClass is
- * non-primitive.</p>
- *
- * <p>Specifically, this method tests whether the type represented by the
- * specified <code>Class</code> parameter can be converted to the type
- * represented by this <code>Class</code> object via an identity conversion
- * widening primitive or widening reference conversion. See
- * <em><a href="http://java.sun.com/docs/books/jls/">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</code>
- * @param toClassArray the array of Classes to try to assign into, may be <code>null</code>
- * @return <code>true</code> if assignment possible
- */
- public static boolean isAssignable(Class[] classArray, Class[] toClassArray) {
- if (ArrayUtils.isSameLength(classArray, toClassArray) == false) {
- 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]) == false) {
- return false;
- }
- }
- return true;
- }
-
- /**
- * <p>Checks if one <code>Class</code> can be assigned to a variable of
- * another <code>Class</code>.</p>
- *
- * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method,
- * this method takes into account widenings of primitive classes and
- * <code>null</code>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</code> may be assigned to any reference type. This method
- * will return <code>true</code> if <code>null</code> is passed in and the
- * toClass is non-primitive.</p>
- *
- * <p>Specifically, this method tests whether the type represented by the
- * specified <code>Class</code> parameter can be converted to the type
- * represented by this <code>Class</code> object via an identity conversion
- * widening primitive or widening reference conversion. See
- * <em><a href="http://java.sun.com/docs/books/jls/">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
- * @return <code>true</code> if assignment possible
- */
- public static boolean isAssignable(Class cls, Class toClass) {
- if (toClass == null) {
- return false;
- }
- // have to check for null, as isAssignableFrom doesn't
- if (cls == null) {
- return !(toClass.isPrimitive());
- }
- if (cls.equals(toClass)) {
- return true;
- }
- if (cls.isPrimitive()) {
- if (toClass.isPrimitive() == false) {
- 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);
- }
-
- // Inner class
- // ----------------------------------------------------------------------
- /**
- * <p>Is the specified class an inner class or static nested class.</p>
- *
- * @param cls the class to check
- * @return <code>true</code> if the class is an inner or static nested class,
- * false if not or <code>null</code>
- */
- public static boolean isInnerClass(Class cls) {
- if (cls == null) {
- return false;
- }
- return (cls.getName().indexOf(INNER_CLASS_SEPARATOR_CHAR) >= 0);
- }
-
- }