File	Doc	Category	Size	Date	Package
FilterInputStream.java	API Doc	Java SE 5 API	8161	Fri Aug 26 14:56:58 BST 2005	java.io

FilterInputStream

• java.lang.Object
  • java.io.InputStream

Fields Summary
protected volatile InputStream	in The input stream to be filtered.

Constructors Summary
protected FilterInputStream(InputStream in) Creates a FilterInputStream by assigning the argument in to the field this.in so as to remember it for later use. param in the underlying input stream, or null if this instance is to be created without an underlying stream. this.in = in;

Methods Summary
public int	available() Returns the number of bytes that can be read from this input stream without blocking. This method simply performs in.available() and returns the result. return the number of bytes that can be read from the input stream without blocking. exception IOException if an I/O error occurs. see java.io.FilterInputStream#in return in.available();
public void	close() Closes this input stream and releases any system resources associated with the stream. This method simply performs in.close(). exception IOException if an I/O error occurs. see java.io.FilterInputStream#in in.close();
public synchronized void	mark(int readlimit) Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes. The readlimit argument tells this input stream to allow that many bytes to be read before the mark position gets invalidated. This method simply performs in.mark(readlimit). param readlimit the maximum limit of bytes that can be read before the mark position becomes invalid. see java.io.FilterInputStream#in see java.io.FilterInputStream#reset() in.mark(readlimit);
public boolean	markSupported() Tests if this input stream supports the mark and reset methods. This method simply performs in.markSupported(). return true if this stream type supports the mark and reset method; false otherwise. see java.io.FilterInputStream#in see java.io.InputStream#mark(int) see java.io.InputStream#reset() return in.markSupported();
public int	read() Reads the next byte of data from this 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 has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown. This method simply performs in.read() and returns the result. return the next byte of data, or -1 if the end of the stream is reached. exception IOException if an I/O error occurs. see java.io.FilterInputStream#in return in.read();
public int	read(byte[] b) Reads up to byte.length bytes of data from this input stream into an array of bytes. This method blocks until some input is available. This method simply performs the call read(b, 0, b.length) and returns the result. It is important that it does not do in.read(b) instead; certain subclasses of FilterInputStream depend on the implementation strategy actually used. param b the buffer into which the data is read. return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached. exception IOException if an I/O error occurs. see java.io.FilterInputStream#read(byte[], int, int) return read(b, 0, b.length);
public int	read(byte[] b, int off, int len) Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available. This method simply performs in.read(b, off, len) and returns the result. param b the buffer into which the data is read. param off the start offset of the data. param len the maximum number of bytes read. return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached. exception IOException if an I/O error occurs. see java.io.FilterInputStream#in return in.read(b, off, len);
public synchronized void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream. This method simply performs in.reset(). Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parse, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If this happens within readlimit bytes, it allows the outer code to reset the stream and try another parser. exception IOException if the stream has not been marked or if the mark has been invalidated. see java.io.FilterInputStream#in see java.io.FilterInputStream#mark(int) in.reset();
public long	skip(long n) Skips over and discards n bytes of data from the input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. The actual number of bytes skipped is returned. This method simply performs in.skip(n). param n the number of bytes to be skipped. return the actual number of bytes skipped. exception IOException if an I/O error occurs. return in.skip(n);