import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.net.MalformedURLException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import javax.swing.JButton;

public class Test {
	private static byte[] readAll(InputStream is) throws IOException {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		for (;;) {
			int i = is.read();
			if (i < 0)
				break;
			baos.write(i);
		}
		return baos.toByteArray();
	}

	public static void main(String[] args) throws ClassNotFoundException,
			MalformedURLException, InstantiationException,
			IllegalAccessException, IllegalArgumentException,
			InvocationTargetException, NoSuchMethodException, SecurityException {
		final String jreRt = "c:\\Program Files\\Java\\jdk1.7.0_45\\jre\\lib\\rt.jar";
		ClassLoader loader = new ClassLoader() {
			@Override
			protected Class<?> loadClass(String name, boolean resolve)
					throws ClassNotFoundException {
				if (name.equals("javax.swing.JButton"))
					try {
						@SuppressWarnings("resource")
						ZipFile file = new ZipFile(new File(jreRt));
						ZipEntry entry = file.getEntry(name.replace('.', '/')
								+ ".class");
						byte[] data = readAll(file.getInputStream(entry));
						return defineClass(data, 0, data.length);
					} catch (Throwable t) {
					}
				return Class.forName(name);
			}
		};

		Object button = new javax.swing.JButton();
		Class originalClass = javax.swing.JButton.class;
		Class artificialClass = Class.forName("javax.swing.JButton", false,
				loader);
		Object artificialButton = artificialClass.getConstructor()
				.newInstance();
		System.out.println("class hashCode");
		System.out.println(originalClass.hashCode());
		System.out.println(artificialClass.hashCode());
		System.out.println("----------------------");
		System.out.println("check if new JButton().getClass() == our class");
		System.out.println("Original class: "
				+ (button.getClass() == originalClass));
		System.out.println("Artificial class: "
				+ (button.getClass() == artificialClass));
		System.out.println("----------------------");
		System.out.println("toString for classes");
		System.out.println("originalClass: " + originalClass);
		System.out.println("artificialClass: " + artificialClass);
		System.out.println("------------------");
		System.out.println("Check if classes are the same...");
		System.out.println("artificialButton.getClass() == button.getClass(): "
				+ (artificialButton.getClass() == button.getClass()));
		System.out.println("syntheticObject instanceof JButton: "
				+ (artificialButton instanceof JButton));
		try {
			button = (JButton) artificialButton;
		} catch (ClassCastException e) {
			System.out.println(e);
			System.out.println("Cannot cast from " + JButton.class + " to "
					+ artificialButton.getClass() + "!?!");
		}
		System.out.println("This is the genuine button toString(): " + button);
		try {
			System.out.println("This is the artificial button toString(): "
					+ artificialButton);
			// System.out.println("Trying toartificialButton);"
		} catch (Throwable t) {
			System.out.println(t);
			System.out
					.println("Cannot run toString for the artificial button because:");
			System.out
					.println("AbstractButton.defaultCapable is hidden for classes that don't inherit the AbstractButton.");
			System.out
					.println("And our artificialButton JButton tried to access the AbstractButton protected field.");
			System.out
					.println("And that AbstractButton is the JVM standard class loader - remember if (name.equals(\"javax.swing.JButton\"))?");
		}
	}
}