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  1. JDK
  2. JDK-8214072

InputStream.skipNBytes(long k) to skip exactly k bytes



    • CSR
    • Status: Closed
    • P3
    • Resolution: Approved
    • 12
    • core-libs
    • None
    • source, binary
    • minimal
    • If an existing subclass implements a method with the same signature then there could be a conflict. No such implementations have been found.
    • Java API
    • SE



      Add java.io.InputStream.skipNBytes(long) to skip forward an exact number of bytes.


      The existing method java.io.InputStream.skip(long) does not guarantee that the requested number of bytes will actually be skipped.


      Define a new method java.io.InputStream.skipNBytes(long) which will skip exactly the number of bytes requested or throw an exception.


      Changes to java.io.InputStream.nullInputStream() documentation:

           * {@code readAllBytes()}, {@code readNBytes(byte[], int, int)},
           * {@code readNBytes(int)}, {@code skip(long)}, {@code skipNBytes(long)},

      Changes to java.io.InputStream.skip(long) documentation:

           * @return     the actual number of bytes skipped which might be zero.
           * @throws     IOException  if an I/O error occurs.
           * @see        java.io.InputStream#skipNBytes(long)

      New method java.io.InputStream.skipNBytes(long):

           * Skips over and discards exactly {@code n} bytes of data from this input
           * stream.  If {@code n} is zero, then no bytes are skipped.
           * If {@code n} is negative, then no bytes are skipped.
           * Subclasses may handle the negative value differently.
           * <p> This method blocks until the requested number of bytes have been
           * skipped, end of file is reached, or an exception is thrown.
           * <p> If end of stream is reached before the stream is at the desired
           * position, then an {@code EOFException} is thrown.
           * <p> If an I/O error occurs, then the input stream may be
           * in an inconsistent state. It is strongly recommended that the
           * stream be promptly closed if an I/O error occurs.
           * @implNote
           * Subclasses are encouraged to provide a more efficient implementation
           * of this method.
           * @implSpec
           * If {@code n} is zero or negative, then no bytes are skipped.
           * If {@code n} is positive, the default implementation of this method
           * invokes {@link #skip(long) skip()} with parameter {@code n}.  If the
           * return value of {@code skip(n)} is non-negative and less than {@code n},
           * then {@link #read()} is invoked repeatedly until the stream is {@code n}
           * bytes beyond its position when this method was invoked or end of stream
           * is reached.  If the return value of {@code skip(n)} is negative or
           * greater than {@code n}, then an {@code IOException} is thrown.  Any
           * exception thrown by {@code skip()} or {@code read()} will be propagated.
           * @param      n   the number of bytes to be skipped.
           * @throws     EOFException if end of stream is encountered before the
           *             stream can be positioned {@code n} bytes beyond its position
           *             when this method was invoked.
           * @throws     IOException  if the stream cannot be positioned properly or
           *             if an I/O error occurs.
           * @see        java.io.InputStream#skip(long)
          public void skipNBytes(long n) throws IOException {}


        Issue Links



              bpb Brian Burkhalter
              martin Martin Buchholz
              Roger Riggs
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