| // NewInstance.java - create a new instance of a class by name. |
| // http://www.saxproject.org |
| // Written by Edwin Goei, edwingo@apache.org |
| // and by David Brownell, dbrownell@users.sourceforge.net |
| // NO WARRANTY! This class is in the Public Domain. |
| // $Id: NewInstance.java,v 1.1 2004/12/23 22:38:42 mark Exp $ |
| |
| package org.xml.sax.helpers; |
| |
| import java.lang.reflect.Method; |
| import java.lang.reflect.InvocationTargetException; |
| |
| /** |
| * Create a new instance of a class by name. |
| * |
| * <blockquote> |
| * <em>This module, both source code and documentation, is in the |
| * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> |
| * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a> |
| * for further information. |
| * </blockquote> |
| * |
| * <p>This class contains a static method for creating an instance of a |
| * class from an explicit class name. It tries to use the thread's context |
| * ClassLoader if possible and falls back to using |
| * Class.forName(String).</p> |
| * |
| * <p>This code is designed to compile and run on JDK version 1.1 and later |
| * including versions of Java 2.</p> |
| * |
| * @author Edwin Goei, David Brownell |
| * @version 2.0.1 (sax2r2) |
| */ |
| class NewInstance { |
| |
| /** |
| * Creates a new instance of the specified class name |
| * |
| * Package private so this code is not exposed at the API level. |
| */ |
| static Object newInstance (ClassLoader classLoader, String className) |
| throws ClassNotFoundException, IllegalAccessException, |
| InstantiationException |
| { |
| Class driverClass; |
| if (classLoader == null) { |
| driverClass = Class.forName(className); |
| } else { |
| driverClass = classLoader.loadClass(className); |
| } |
| return driverClass.newInstance(); |
| } |
| |
| /** |
| * Figure out which ClassLoader to use. For JDK 1.2 and later use |
| * the context ClassLoader. |
| */ |
| static ClassLoader getClassLoader () |
| { |
| Method m = null; |
| |
| try { |
| m = Thread.class.getMethod("getContextClassLoader", null); |
| } catch (NoSuchMethodException e) { |
| // Assume that we are running JDK 1.1, use the current ClassLoader |
| return NewInstance.class.getClassLoader(); |
| } |
| |
| try { |
| return (ClassLoader) m.invoke(Thread.currentThread(), null); |
| } catch (IllegalAccessException e) { |
| // assert(false) |
| throw new UnknownError(e.getMessage()); |
| } catch (InvocationTargetException e) { |
| // assert(e.getTargetException() instanceof SecurityException) |
| throw new UnknownError(e.getMessage()); |
| } |
| } |
| } |