Generate, Compile and Run java class through Java program

I am trying to generate ,compile and run Java Class through program using reflection. I am able to successfully generate and compile the file but when running the file, getting the ClassNotFoundException.

package javaapplication2;

/**
 *
 * @author sachin.maurya
 */
import java.io.*;
import java.util.*;
import java.lang.reflect.*;
import java.lang.ClassLoader;
public class MakeTodayClass {
  Date today = new Date();
  String todayMillis = Long.toString(today.getTime());
  String todayClass = "z_" + todayMillis;
  String todaySource = "C:\\Users\\sachin.maurya\\Documents\\NetBeansProjects\\JavaApplication2\\src\\javaapplication2\\"+todayClass + ".java";

  public static void main (String args[]) throws InterruptedException, IOException, ClassNotFoundException, InstantiationException, IllegalAccessException{
    MakeTodayClass mtc = new MakeTodayClass();
    mtc.createIt();
    if (mtc.compileIt()) {
       System.out.println("Running " + mtc.todayClass + ":\n\n");
        Thread.sleep(2000);
       mtc.runIt();
       }
    else
       System.out.println(mtc.todaySource + " is bad.");
    }

  public void createIt() {
    try {
      FileWriter aWriter = new FileWriter(todaySource, true);
      aWriter.write("public class "+ todayClass + "{");
      aWriter.write(" public void doit() {");
      aWriter.write(" System.out.println(\""+todayMillis+"\");");
      aWriter.write(" }}\n");
      aWriter.flush();      
      aWriter.close();
      }
    catch(Exception e){
      e.printStackTrace();
      }
    }

  public boolean compileIt() {
    String [] source = { new String(todaySource)};
    ByteArrayOutputStream baos= new ByteArrayOutputStream();

    new sun.tools.javac.Main(baos,source[0]).compile(source);
   return (baos.toString().indexOf("error")==-1);
    }

  public void runIt() throws IOException, ClassNotFoundException, InstantiationException, IllegalAccessException {
    try {
      Class params[] = {};
      Object paramsObj[] = {};
      Class thisClass = Class.forName(todayClass);
      Object iClass = thisClass.newInstance();
      Method thisMethod = thisClass.getDeclaredMethod("doit", params);
      thisMethod.invoke(iClass, paramsObj);
      }
    catch (Exception e) {
      e.printStackTrace();
      }

  }

}

---

run:

Running z_1462876181460:


1462874906040
javaapplication2.Runner.runner()
java.lang.ClassNotFoundException: z_1462876181460
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at javaapplication2.Runner.runner(Runner.java:24)
    at javaapplication2.MakeTodayClass.runIt(MakeTodayClass.java:70)
    at javaapplication2.MakeTodayClass.main(MakeTodayClass.java:28)
BUILD SUCCESSFUL (total time: 2 seconds)

When I hardcode the value of 'todayClass' value i.e. some class file generated earlier then runIt() function is working properly, So it seems to be due to workflow of ClassLoader but I am not sure. Is it possible to run generated .class file ?