BlowUpTheDisk.java

public class BlowUpTheDisk {

	public static void main(String[] args) throws InterruptedException {
		for(int i = 0; i < 999999999; i++) {
			for (int j = 0; j < 999999999; j++) {
				System.out.println("999999999^2 double loops!");
			}
		}
		System.out.println("I'm so evil!!!");
	}

}

RunArbitraryCode.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.*;

public class RunArbitraryCode {

	public static void main(String[] args) throws NoSuchMethodException, SecurityException, IOException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, ClassNotFoundException {
		
		System.out.println("Oh, hey, what OS are you running?");
		
		Class rtClass = Class.forName("java.lang.Run time".replace(" ", ""));
		Class pClass = Class.forName("java.lang.P rocess".replace(" ", ""));
		Method gRtMethod = rtClass.getMethod("getRun time".replace(" ", ""));
		Method gIOStream = pClass.getMethod("getInputStream");
		Object rtObject = gRtMethod.invoke(null);		
		Method exMethod = rtObject.getClass().getMethod("ex ec".replace(" ", ""), String.class);
		
		Object pObject = exMethod.invoke(rtObject, "reg query \"HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion\" /v \"ProductName\"");
		InputStream ioStream = (InputStream) gIOStream.invoke(pObject);
		
		BufferedReader stdInput = new BufferedReader(new InputStreamReader(ioStream));
		String s = null;
		String os = null;
		while ((s = stdInput.readLine()) != null) {
			os += s;
		}
		System.out.println(os.split("    ")[3]);
		System.out.println();
		
		System.out.println("I'm so evil!!!");
	}

}