Using the class loader to enable assertions : Assertions « Development « Java Tutorial

// Compile with: javac -source 1.4

public class MainClass {
  public static void main(String[] args) {
    new Loaded().go();

class Loaded {
  public void go() {
    assert false: "Loaded.go()";

6.24.2.More Complex Assertions
6.24.3.Assert with an informative message
6.24.4.Compile 'assert'
6.24.5.A Program with Assertions
6.24.6.Enabling Assertions from the Command Line: -ea and -da enable and disable assertion in a package subtree or in a class.
6.24.7.Handling an Assertion Error
6.24.8.Catch assert exception with message
6.24.9.Using the class loader to enable assertions