Why Java Exists

public class Journey {

    // TODO: the five stages, in order, from the file you type to the instructions
    // a processor runs. Use exactly these five words, in the right order:
    //     source, compiling, bytecode, jvm, machine-code
    static String[] stagesInOrder() {
        return new String[]{};
    }

    // TODO
    static String extensionOfWhatYouWrite()          { return "?"; }

    // TODO
    static String extensionOfWhatTheCompilerMakes()  { return "?"; }

    // TODO: how many files are in this story?
    static int filesInTheStory() { return 1; }

    // TODO: which stage happens once, however many computers run the program?
    static String stageThatHappensOnce() { return "?"; }

    // TODO: which stage happens again on every computer, every single run?
    static String stageThatHappensOnEveryMachine() { return "?"; }

    // TODO: true if this stage happens on YOUR machine rather than the one
    // running the program.
    static boolean happensOnYourMachine(String stage) {
        return true;
    }

    public static void main(String[] args) {
        int step = 1;
        for (String stage : stagesInOrder()) {
            System.out.println(step++ + ". " + stage
                    + (happensOnYourMachine(stage) ? "   (your machine)" : "   (theirs)"));
        }
    }
}

public class WillItRun {

    // TODO: a compiled C++ binary. When does it run on the target machine?
    static boolean cppRuns(String builtOs, String builtArch, String targetOs, String targetArch) {
        return true;
    }

    // TODO: a .class file. Ask a different question from the one above.
    static boolean javaRuns(String builtOs, String builtArch,
                            String targetOs, String targetArch, boolean jvmInstalled) {
        return true;
    }

    // TODO: which half of the platform moved?
    // "nothing", "os", "processor" or "both"
    static String whatChanged(String builtOs, String builtArch, String targetOs, String targetArch) {
        return "?";
    }

    // TODO
    static boolean classFileDependsOnThePlatform() { return true; }

    public static void main(String[] args) {
        // The six cases from the exercise. Answer them on paper first.
        System.out.println("1 " + cppRuns("Windows", "Intel", "Windows", "Intel"));
        System.out.println("2 " + cppRuns("Windows", "Intel", "Linux", "Intel"));
        System.out.println("3 " + cppRuns("Windows", "Intel", "Windows", "ARM"));
        System.out.println("4 " + javaRuns("Windows", "Intel", "Linux", "Intel", true));
        System.out.println("5 " + javaRuns("Windows", "Intel", "Linux", "ARM", true));
        System.out.println("6 " + javaRuns("Windows", "Intel", "Linux", "ARM", false));
    }
}