2.1. How do I write a test?

The simplest test is an ordinary Java program with the usual static main method. If the test fails, it should throw an exception; if it succeeds, it should return normally.

Here's an example:

                        /* @test 1.1 97/10/12
                           @bug 1234567
                           @summary Make sure that 1 != 0
                        */

                        public class OneZero {

                            public static void main(String[] args) throws Exception {
                                if (1 == 0) {
                                    throw new Exception("1 == 0");
                                }
                            }

                        }
                    

This test could be run on its own with the command

                    <build>/bin/java OneZero
                
where <build> is the location of the JDK build that you're testing.