import javax.microedition.lcdui.Display;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class Principal extends MIDlet {

Display p;
JZLoader loader;

public Principal() {
p=Display.getDisplay(this);
loader=new JZLoader("Java Zone ME",30);
Thread t=new Thread(loader);
t.start();
}

protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
}

protected void pauseApp() {
}

protected void startApp() throws MIDletStateChangeException {
p.setCurrent(loader);
}
}

import javax.microedition.lcdui.*;

public class JZLoader extends Canvas implements Runnable{

String mensaje="";
String estado="Cargando";
int maximo=getWidth()-40;
int valor=20;
int velocidad=50;
public JZLoader(String men, int v){
mensaje=men;
velocidad=v;
}
protected void paint(Graphics g) {
g.setColor(255, 255, 255);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(0, 0, 0);
g.setFont(Font.getFont(Font.FACE_SYSTEM,Font.STYLE_BOLD,Font.SIZE_LARGE));
g.drawString(mensaje, getWidth()/2, getHeight()/2-30, Graphics.BASELINE|Graphics.HCENTER);
g.setColor(255, 200, 80);
g.drawRoundRect(20, getHeight()/2, getWidth()-40, 20, 25, 25);
g.fillRoundRect(20, getHeight()/2, valor, 20, 25, 25);
g.setColor(100,100,100);
g.drawString(estado, getWidth()/2, getHeight()/2+50, Graphics.BASELINE|Graphics.HCENTER);
}

public void run() {
while(valor<maximo){
try {
valor+=2;
Thread.sleep(velocidad);
repaint();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
estado="Completado";
repaint();
}
}