net.rim.device.api.compress
Class ZLibInputStream

java.lang.Object
  |
  +--java.io.InputStream
        |
        +--net.rim.device.api.compress.ZLibInputStream

public class ZLibInputStream

extends InputStream

Input stream for reading a data stream compressed with the ZLib algorithm (RFC 1950, RFC 1951).

Constructor Summary

ZLibInputStream(InputStream inputStream)
Creates a new ZLibInputStream instance (which requires the ZLib header and trailer wrapping to be present - see other constructor).

ZLibInputStream(InputStream inputStream, boolean noWrap)
Creates a new ZLibInputStream instance.

Method Summary

int	available() Retreives number of bytes which can be read from this stream without blocking.
void	close() Closes this stream.
int	read() Retrieves one byte from this input stream.
int	read(byte[] buffer) Reads some bytes from this stream.
int	read(byte[] buffer, int bufferOffset, int bufferLength) Read specified number of bytes from this stream.

Methods inherited from class java.io.InputStream

mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ZLibInputStream

public ZLibInputStream(InputStream inputStream)

Creates a new ZLibInputStream instance (which requires the ZLib header and trailer wrapping to be present - see other constructor).

Parameters:

inputStream - Underlying input stream to use.

ZLibInputStream

public ZLibInputStream(InputStream inputStream,
                       boolean noWrap)

Creates a new ZLibInputStream instance.

If noWrap is true, the decompressor will assume that the ZLib 16 bit header and the 32 bit trailer checksum are not included in the underlying input stream. This mode is necessary for PKZip/Info-ZIP and GZIP compatibility.

Parameters:

inputStream - Underlying input stream to use.

noWrap - If true, the header and trailer are not present in the underlying input stream.

Method Detail

read

public int read()
         throws IOException

Retrieves one byte from this input stream.

Overrides:

read in class InputStream

Returns:

Byte of decompressed data, or -1 if no more data in this stream.

Throws:

IOException - If an I/O error occurs.

read

public int read(byte[] buffer)
         throws IOException

Reads some bytes from this stream.

Invoke this method to attempt to fill a provided output parameter byte array with data from this stream.

Overrides:

read in class InputStream

Parameters:

buffer - Buffer to contain read and decompressed data.

Returns:

0 if length of output parameter byte array is zero; otherwise, the number of bytes actually read into the buffer. If no more data was available when you invoked this method, it returns -1.

Throws:

IOException - If an I/O error occurs.

Since:

JDE 3.6

read

public int read(byte[] buffer,
                int bufferOffset,
                int bufferLength)
         throws IOException

Read specified number of bytes from this stream.

Overrides:

read in class InputStream

Parameters:

buffer - Buffer to contain data; must be large enough to contain desired number of bytes.

bufferOffset - First element in output parameter buffer at which to begin writing decoded data; if not 0, then output parameter buffer must be at least bufferOffset + bufferLength elements long.

bufferLength - Number of bytes to read from this stream.

Returns:

0 if length of output parameter byte array is zero; otherwise, the number of bytes actually read into the buffer. If no more data was available when you invoked this method, it returns -1.

Throws:

IOException - If an I/O error occurs.

Since:

JDE 3.6

available

public int available()
              throws IOException

Retreives number of bytes which can be read from this stream without blocking.

Overrides:

available in class InputStream

Returns:

Number of bytes availble to be read without blocking.

Throws:

IOException - If an I/O error occurs.

close

public void close()
           throws IOException

Closes this stream.

Overrides:

close in class InputStream

Throws:

IOException - If an I/O error occurs.