--- old/src/java.base/share/classes/java/io/InputStream.java 2017-12-06 10:54:10.000000000 -0800 +++ new/src/java.base/share/classes/java/io/InputStream.java 2017-12-06 10:54:09.000000000 -0800 @@ -54,6 +54,106 @@ private static final int DEFAULT_BUFFER_SIZE = 8192; /** + * Returns a new {@code InputStream} that contains no bytes. The returned + * stream is initially open. The stream is closed by calling the + * {@code close()} method. Subsequent calls to {@code close()} have no + * effect. + * + *

While the stream is open, the {@code available()}, {@code read()}, + * {@code read(byte[])}, {@code read(byte[], int, int)}, + * {@code readAllBytes()}, {@code readNBytes()}, {@code skip()}, and + * {@code transferTo()} methods all behave as if end of stream has been + * reached. After the stream has been closed, these methods all throw + * {@code IOException}. + * + *

The {@code markSupported()} method returns {@code false}. The + * {@code mark()} method does nothing, and the {@code reset()} method + * throws {@code IOException}. + * + * @return an {@code InputStream} which contains no bytes + * + * @since 10 + */ + public static InputStream nullStream() { + return new InputStream() { + private volatile boolean closed; + + @Override + public int available () throws IOException { + if (closed) { + throw new IOException("Stream closed"); + } + return 0; + } + + @Override + public int read() throws IOException { + if (closed) { + throw new IOException("Stream closed"); + } + return -1; + } + + @Override + public int read(byte[] b, int off, int len) throws IOException { + Objects.requireNonNull(b); + Objects.checkFromIndexSize(off, len, b.length); + if (len == 0) { + return 0; + } else if (closed) { + throw new IOException("Stream closed"); + } + return -1; + } + + @Override + // overridden for efficiency + public byte[] readAllBytes() throws IOException { + if (closed) { + throw new IOException("Stream closed"); + } + return new byte[0]; + } + + @Override + // overridden for efficiency + public int readNBytes(byte[] b, int off, int len) + throws IOException { + Objects.requireNonNull(b); + Objects.checkFromIndexSize(off, len, b.length); + if (closed) { + throw new IOException("Stream closed"); + } + return 0; + } + + @Override + // overridden for efficiency + public long skip(long n) throws IOException { + if (closed) { + throw new IOException("Stream closed"); + } + return 0L; + } + + @Override + // overridden for efficiency + public long transferTo(OutputStream out) throws IOException { + Objects.requireNonNull(out); + if (closed) { + throw new IOException("Stream closed"); + } + return 0L; + } + + @Override + public void close() throws IOException { + closed = true; + } + }; + } + + /** * Reads the next byte of data from the input stream. The value byte is * returned as an int in the range 0 to * 255. If no byte is available because the end of the stream