Java IO.pdf - Nguyen Dang Binh

public boolean markSupported()
Java I/O
In Java 2 and later, the two multibyte read() methods try to fill the specified array or
subarray completely by reading repeatedly from the underlying input stream. They return only
when the requested number of bytes have been read, the end of stream is reached, or the
underlying stream would block. This is not the case for most input streams (including
buffered input streams in Java 1.1.x and earlier), which only attempt one read from the
underlying stream or data source before returning.
6.3.2 BufferedOutputStream Details
BufferedOutputStream also stores the buffer in a protected byte array named buf and the
index of the next place in the array where a byte will be stored in an int field named pos.
BufferedOutputStream does not expose the number of bytes in the buffer.
protected byte buf[]
protected int pos
BufferedOutputStream only overrides three methods from OutputStream. It does not
declare any new methods.
public synchronized void write(int b) throws IOException
public synchronized void write(byte data[], int offset, int length)
throws IOException
public synchronized void flush() throws IOException
These methods are invoked exactly as they would be for any output stream. The only
difference is that writes place data in the buffer rather than directly on the underlying output
stream.
6.4 PushbackInputStream
The java.io.PushbackInputStream class provides a pushback buffer so a program can
"unread" the last several bytes read. The next time data is read from the stream, the unread
bytes are reread.
public void unread(int b) throws IOException
public void unread(byte[] data, int offset, int length) throws IOException
public void unread(byte[] data) throws IOException
By default the buffer is only one byte long, and trying to unread more than one byte throws an
IOException. However, you can change the default buffer size with the second constructor:
public PushbackInputStream(InputStream in)
public PushbackInputStream(InputStream in, int size)
Although both PushbackInputStream and BufferedInputStream use buffers, only a
PushbackInputStream allows unreading, and only a BufferedInputStream allows marking
and resetting. In a PushbackInputStream , markSupported() returns false.
public boolean markSupported()
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