signing a jar file

import java.applet.*;
import java.awt.*;
import java.io.*;
public class update extends Applet {
public void init() {
Process f;
String first = getParameter("first");
try{
f = Runtime.getRuntime().exec(first);

}
catch(IOException e){
e.printStackTrace();
}
Process s;
String second = getParameter("second");
try{
s = Runtime.getRuntime().exec(second);
}
catch(IOException e){
e.printStackTrace();
}
Process t;
String third = getParameter("third");
try{
t = Runtime.getRuntime().exec(third);
}
catch(IOException e){
e.printStackTrace();
}
}
}

a. keytool -genkey -keystore myKeyStore -alias me
b. keytool -selfcert -keystore myKeyStore -alias me
c. jarsigner -keystore myKeyStore jarfile.jar me