Re: Is System.in an object?

On Apr 27, 10:16 am, "shuch...@gmail.com" <shuch...@gmail.com> wrote:


public final static InputStream in = nullInputStream();

    /**
     * The following two methods exist because in, out, and err must
be
     * initialized to null. The compiler, however, cannot be
permitted to
     * inline access to them, since they are later set to more
sensible values
     * by initializeSystemClass().
     */

    private static InputStream nullInputStream() throws
NullPointerException {
    if (currentTimeMillis() > 0)
        return null;
    throw new NullPointerException();
    }

    private static PrintStream nullPrintStream() throws
NullPointerException {
    if (currentTimeMillis() > 0)
        return null;
    throw new NullPointerException();
    }

    /**
     * Initialize the system class. Called after thread
initialization.
     */
    private static void initializeSystemClass() {
    props = new Properties();
    initProperties(props);
    sun.misc.Version.init();
    FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
    FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
    FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
    setIn0(new BufferedInputStream(fdIn));
    setOut0(new PrintStream(new BufferedOutputStream(fdOut, 128), true));
    setErr0(new PrintStream(new BufferedOutputStream(fdErr, 128), true));

    // Load the zip library now in order to keep java.util.zip.ZipFile
    // from trying to use itself to load this library later.
    loadLibrary("zip");

        // Currently File.deleteOnExit is built on JVM_Exit, which is
a
        // separate mechanism from shutdown hooks. Unfortunately in
order to
        // work properly JVM_Exit implicitly requires that Java signal
        // handlers be set up for HUP, TERM, and INT (where
available). If
        // File.deleteOnExit were implemented in terms of shutdown
hooks this
        // call to Terminator.setup() could be removed.
        Terminator.setup();

    // Set the maximum amount of direct memory. This value is controlled
    // by the vm option -XX:MaxDirectMemorySize=<size>. This method acts
    // as an initializer only if it is called before
sun.misc.VM.booted().
  sun.misc.VM.maxDirectMemory();

    // Subsystems that are invoked during initialization can invoke
    // sun.misc.VM.isBooted() in order to avoid doing things that should
    // wait until the application class loader has been set up.
    sun.misc.VM.booted();

        // The main thread is not added to its thread group in the
same
        // way as other threads; we must do it ourselves here.
        Thread current = Thread.currentThread();
        current.getThreadGroup().add(current);

        // Allow privileged classes outside of java.lang access to
ConstantPool
        sun.misc.SharedSecrets.setJavaLangAccess(new
sun.misc.JavaLangAccess(){
            public sun.reflect.ConstantPool getConstantPool(Class
klass) {
                return klass.getConstantPool();
            }
        });
    }