319      *   <li> The <code>available</code> method of the underlying stream
 320      *   returns zero, indicating that further input requests would block.
 321      *
 322      * </ul> If the first <code>read</code> on the underlying stream returns
 323      * <code>-1</code> to indicate end-of-file then this method returns
 324      * <code>-1</code>.  Otherwise this method returns the number of bytes
 325      * actually read.
 326      *
 327      * <p> Subclasses of this class are encouraged, but not required, to
 328      * attempt to read as many bytes as possible in the same fashion.
 329      *
 330      * @param      b     destination buffer.
 331      * @param      off   offset at which to start storing bytes.
 332      * @param      len   maximum number of bytes to read.
 333      * @return     the number of bytes read, or <code>-1</code> if the end of
 334      *             the stream has been reached.
 335      * @exception  IOException  if this input stream has been closed by
 336      *                          invoking its {@link #close()} method,
 337      *                          or an I/O error occurs.
 338      */
 339     public synchronized int read(byte b[], int off, int len)
 340         throws IOException
 341     {
 342         getBufIfOpen(); // Check for closed stream
 343         if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
 344             throw new IndexOutOfBoundsException();
 345         } else if (len == 0) {
 346             return 0;
 347         }
 348 
 349         int n = 0;
 350         for (;;) {
 351             int nread = read1(b, off + n, len - n);
 352             if (nread <= 0)
 353                 return (n == 0) ? nread : n;
 354             n += nread;
 355             if (n >= len)
 356                 return n;
 357             // if not closed but no bytes available, return
 358             InputStream input = in;
 359             if (input != null && input.available() <= 0)

 319      *   <li> The <code>available</code> method of the underlying stream
 320      *   returns zero, indicating that further input requests would block.
 321      *
 322      * </ul> If the first <code>read</code> on the underlying stream returns
 323      * <code>-1</code> to indicate end-of-file then this method returns
 324      * <code>-1</code>.  Otherwise this method returns the number of bytes
 325      * actually read.
 326      *
 327      * <p> Subclasses of this class are encouraged, but not required, to
 328      * attempt to read as many bytes as possible in the same fashion.
 329      *
 330      * @param      b     destination buffer.
 331      * @param      off   offset at which to start storing bytes.
 332      * @param      len   maximum number of bytes to read.
 333      * @return     the number of bytes read, or <code>-1</code> if the end of
 334      *             the stream has been reached.
 335      * @exception  IOException  if this input stream has been closed by
 336      *                          invoking its {@link #close()} method,
 337      *                          or an I/O error occurs.
 338      */
 339     public synchronized int read(byte[] b, int off, int len)
 340         throws IOException
 341     {
 342         getBufIfOpen(); // Check for closed stream
 343         if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
 344             throw new IndexOutOfBoundsException();
 345         } else if (len == 0) {
 346             return 0;
 347         }
 348 
 349         int n = 0;
 350         for (;;) {
 351             int nread = read1(b, off + n, len - n);
 352             if (nread <= 0)
 353                 return (n == 0) ? nread : n;
 354             n += nread;
 355             if (n >= len)
 356                 return n;
 357             // if not closed but no bytes available, return
 358             InputStream input = in;
 359             if (input != null && input.available() <= 0)