ClassPathHacker.java

package com.plugtree.solrmeter;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
/**
 * 
 * From Oracle Sun Forum
 * Modify Classpath At Runtime   
 * 17-sep-2002 4:02 
 * antony_miguel  
 */
public class ClassPathHacker {

	private static final Class<?>[] parameters = new Class[]{URL.class};
	 
	public static void addFile(String s) throws IOException {
		File f = new File(s);
		addFile(f);
	}//end method
	 
	@SuppressWarnings("deprecation")
	public static void addFile(File f) throws IOException {
		addURL(f.toURL());
	}//end method
	 
	 
	@SuppressWarnings({ "unchecked" })
	public static void addURL(URL u) throws IOException {
			
		URLClassLoader sysloader = (URLClassLoader)ClassLoader.getSystemClassLoader();
		Class sysclass = URLClassLoader.class;
	 
		try {
			Method method = sysclass.getDeclaredMethod("addURL",parameters);
			method.setAccessible(true);
			method.invoke(sysloader,new Object[]{ u });
		} catch (Throwable t) {
			throw new IOException("Error, could not add URL to system classloader");
		}//end try catch
			
	}//end method
}