Is there any way to run the jar file generated by Java in Java, not cmd?

ProcessBuilder pb = new ProcessBuilder("/path/to/java", "-jar", "your.jar");
pb.directory(new File("preferred/working/directory"));
Process p = pb.start();

/*
 * * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
 *
 * * Redistribution and use in source and binary forms, with or without
 * * modification, are permitted provided that the following conditions
 * * are met:
 *
 *   *   - Redistributions of source code must retain the above copyright
 *     *     notice, this list of conditions and the following disclaimer.
 *
 *   *   - 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.
 *
 *   *   - Neither the name of Oracle or the names of its
 *     *     contributors may be used to endorse or promote products derived
 *     *     from this software without specific prior written permission.
 *
 * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR
 * * 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.
 */

import java.net.URL;
import java.net.URLClassLoader;
import java.net.JarURLConnection;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.InvocationTargetException;
import java.util.jar.Attributes;
import java.io.IOException;

/**
 * * A class loader for loading jar files, both local and remote.
 */
class JarClassLoader extends URLClassLoader {
    private URL url;

    /**
     * * Creates a new JarClassLoader for the specified url.
     *
     * * @param url the url of the jar file
     */
    public JarClassLoader(URL url) {
        super(new URL[] { url });
        this.url = url;
    }

    /**
     * * Returns the name of the jar file main class, or null if
     * * no "Main-Class" manifest attributes was defined.
     */
    public String getMainClassName() throws IOException {
        URL u = new URL("jar", "", url + "!/");
        JarURLConnection uc = (JarURLConnection)u.openConnection();
        Attributes attr = uc.getMainAttributes();
        return attr != null ? attr.getValue(Attributes.Name.MAIN_CLASS) : null;
    }

    /**
     * * Invokes the application in this jar file given the name of the
     * * main class and an array of arguments. The class must define a
     * * static method "main" which takes an array of String arguemtns
     * * and is of return type "void".
     *
     * * @param name the name of the main class
     * * @param args the arguments for the application
     * * @exception ClassNotFoundException if the specified class could not
     *            *            be found
     * * @exception NoSuchMethodException if the specified class does not
     *            *            contain a "main" method
     * * @exception InvocationTargetException if the application raised an
     *            *            exception
     */
    public void invokeClass(String name, String[] args)
        throws ClassNotFoundException,
               NoSuchMethodException,
               InvocationTargetException
    {
        Class c = loadClass(name);
        Method m = c.getMethod("main", new Class[] { args.getClass() });
        m.setAccessible(true);
        int mods = m.getModifiers();
        if (m.getReturnType() != void.class || !Modifier.isStatic(mods) ||
            !Modifier.isPublic(mods)) {
            throw new NoSuchMethodException("main");
        }
        try {
            m.invoke(null, new Object[] { args });
        } } catch (IllegalAccessException e) {
            // // This should not happen, as we have disabled access checks
        }
    }

}