EJob

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;

public class EJob {

// To declare global field
private static List<URL> classPath = new ArrayList<URL>();

// To declare method
public static File createTempJar(String root) throws IOException {
if (!new File(root).exists()) {
return null;
}
Manifest manifest = new Manifest();
manifest.getMainAttributes().putValue("Manifest-Version", "1.0");
final File jarFile = File.createTempFile("EJob-", ".jar", new File(
System.getProperty("java.io.tmpdir")));

Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
jarFile.delete();
}
});

JarOutputStream out = new JarOutputStream(
new FileOutputStream(jarFile), manifest);
createTempJarInner(out, new File(root), "");
out.flush();
out.close();
return jarFile;
}

private static void createTempJarInner(JarOutputStream out, File f,
String base) throws IOException {
if (f.isDirectory()) {
File[] fl = f.listFiles();
if (base.length() > 0) {
base = base + "/";
}
for (int i = 0; i < fl.length; i++) {
createTempJarInner(out, fl[i], base + fl[i].getName());
}
} else {
out.putNextEntry(new JarEntry(base));
FileInputStream in = new FileInputStream(f);
byte[] buffer = new byte[1024];
int n = in.read(buffer);
while (n != -1) {
out.write(buffer, 0, n);
n = in.read(buffer);
}
in.close();
}
}

public static ClassLoader getClassLoader() {
ClassLoader parent = Thread.currentThread().getContextClassLoader();
if (parent == null) {
parent = EJob.class.getClassLoader();
}
if (parent == null) {
parent = ClassLoader.getSystemClassLoader();
}
return new URLClassLoader(classPath.toArray(new URL[0]), parent);
}

public static void addClasspath(String component) {

if ((component != null) && (component.length() > 0)) {
try {
File f = new File(component);

if (f.exists()) {
URL key = f.getCanonicalFile().toURL();
if (!classPath.contains(key)) {
classPath.add(key);
}
}
} catch (IOException e) {
}
}
}
}