diff --git a/src/java/org/apache/commons/lang/ClassUtils.java b/src/java/org/apache/commons/lang/ClassUtils.java new file mode 100644 index 000000000..eb4bbea06 --- /dev/null +++ b/src/java/org/apache/commons/lang/ClassUtils.java @@ -0,0 +1,221 @@ +package org.apache.commons.lang; + +/* ==================================================================== + * The Apache Software License, Version 1.1 + * + * Copyright (c) 2002 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 acknowlegement: + * "This product includes software developed by the + * Apache Software Foundation (http://www.apache.org/)." + * Alternately, this acknowlegement may appear in the software itself, + * if and wherever such third-party acknowlegements 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 + * . + */ + +/** + * A set of static utilities for use with ClassUtils. + * + * @author bayard@generationjava.com + * @version $Id: ClassUtils.java,v 1.1 2002/08/14 04:51:28 bayard Exp $ + */ +final public class ClassUtils { + + /** + * Create an object from the classname. Must have an empty constructor. + * + * @param classname String name of the class + * + * @return Object instance of the class or null + */ + static public Object createObject(String classname) { + Class tmpClass = null; + + tmpClass = getClass(classname); + + return createObject(tmpClass); + } + + /** + * Create an object from a class. + * + * @param clss Class object to instantiate + * + * @return Object instance of the class or null + */ + static public Object createObject(Class clss) { + + try { + return clss.newInstance(); + } catch (IllegalAccessException iae) { + System.err.println("Cant instantiate " + clss.getName() + " because " + + iae.getMessage()); + } catch (InstantiationException ie) { + System.err.println("Cant instantiate " + clss.getName() + " because " + + ie.getMessage()); + } + + return null; + } + + /** + * Is this Class in the CLASSPATH + * + * @param classname String of the class + * + * @return boolean exists or not. + */ + static public boolean classExists(String classname) { + Class tmpClass = null; + + /* try and load class */ + try { + tmpClass = Class.forName(classname); + } catch (ClassNotFoundException cnfe) { + return false; + } catch (IllegalArgumentException iae) { + return false; + } + + return true; + } + + /** + * Get the Class object for a classname. + * + * @param classname String of the class + * + * @return Class instance for the class. + */ + static public Class getClass(String classname) { + Class tmpClass = null; + + /* try an load class */ + try { + tmpClass = Class.forName(classname); + } catch (ClassNotFoundException cnfe) { + System.out.println("Can't resolve classname " + classname); + } catch (IllegalArgumentException iae) { + System.err.println("Cant resolve " + tmpClass.getName() + " because " + iae.getMessage()); + } + + return tmpClass; + } + + /** + * Is this Class object an instance of the class with this name. + * + * @param clss Class instance + * @param inst String name of potential supertype + * + * @return boolean was it an instanceof + */ + static public boolean classInstanceOf(Class clss, String inst) { + if(classImplements(clss,inst)) { + return true; + } else + if(classExtends(clss,inst)) { + return true; + } else { + return false; + } + } + + /** + * Does this Class implement an interface with this name. + * + * @param clss Class instance + * @param exts String name of potential interface + * + * @return boolean was it an implementor + */ + static public boolean classImplements(Class clss, String exts) { + + Class sprcls = clss; + Class excls = getClass(exts); + + while(sprcls != null) { + Class[] interfaces = sprcls.getInterfaces(); + + for(int i=0;i