/** @version 1.00 1997-09-10 @author Cay Horstmann */ import java.awt.*; import java.applet.*; /** This application demonstrates the bytecode verifier of the virtual machine. If you use a hex editor to modify the class file, then the virtual machine should detect the tampering. */ public class VerifierTest extends Applet { public static void main(String[] args) { System.out.println("1 + 2 == " + fun()); } /** A function that computes 1 + 2 @return 3, if the code has not been corrupted */ public static int fun() { int m; int n; m = 1; n = 2; // use hex editor to change to "m = 2" in class file int r = m + n; return r; } public void paint(Graphics g) { g.drawString("1 + 2 == " + fun(), 20, 20); } }