Module java.base

Package java.util.zip

Class InflaterInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.util.zip.InflaterInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

GZIPInputStream, ZipInputStream

public class InflaterInputStream
extends FilterInputStream

This class implements a stream filter for uncompressing data in the "deflate" compression format. It is also used as the basis for other decompression filters, such as GZIPInputStream.

Since:

1.1

See Also:

• Inflater

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	buf	Input buffer for decompression.
protected Inflater	inf	Decompressor for this stream.
protected int	len	The total number of bytes read into the input buffer.

Fields declared in class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
InflaterInputStream(InputStream in)	Creates a new input stream with a default decompressor and buffer size.
InflaterInputStream(InputStream in, Inflater inf)	Creates a new input stream with the specified decompressor and a default buffer size.
InflaterInputStream(InputStream in, Inflater inf, int size)	Creates a new input stream with the specified decompressor and buffer size.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns 0 after EOF has been reached, otherwise always return 1.
void	close()	Closes this input stream and releases any system resources associated with the stream.
protected void	fill()	Fills input buffer with more data to decompress.
void	mark(int readlimit)	Marks the current position in this input stream.
boolean	markSupported()	Tests if this input stream supports the mark and reset methods.
int	read()	Reads a byte of uncompressed data.
int	read(byte[] b, int off, int len)	Reads uncompressed data into an array of bytes, returning the number of inflated bytes.
void	reset()	Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n)	Skips specified number of bytes of uncompressed data.

Methods declared in class java.io.FilterInputStream

read

Methods declared in class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods declared in class java.lang.Object

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

Field Details

inf

protected Inflater inf

Decompressor for this stream.

buf

protected byte[] buf

Input buffer for decompression.

len

protected int len

The total number of bytes read into the input buffer.

Constructor Details

InflaterInputStream

public InflaterInputStream(InputStream in,
 Inflater inf,
 int size)

Creates a new input stream with the specified decompressor and buffer size.

Parameters:

in - the input stream

inf - the decompressor ("inflater")

size - the input buffer size

Throws:

IllegalArgumentException - if size <= 0

InflaterInputStream

public InflaterInputStream(InputStream in,
 Inflater inf)

Creates a new input stream with the specified decompressor and a default buffer size.

Parameters:

in - the input stream

inf - the decompressor ("inflater")

InflaterInputStream

public InflaterInputStream(InputStream in)

Creates a new input stream with a default decompressor and buffer size.

Parameters:

in - the input stream

Method Details

read

public int read()
         throws IOException

Reads a byte of uncompressed data. This method will block until enough input is available for decompression.

Overrides:

read in class FilterInputStream

Returns:

the byte read, or -1 if end of compressed input is reached

Throws:

IOException - if an I/O error has occurred

See Also:

• FilterInputStream.in

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Reads uncompressed data into an array of bytes, returning the number of inflated bytes. If len is not zero, the method will block until some input can be decompressed; otherwise, no bytes are read and 0 is returned.

If this method returns a nonzero integer n then buf[off] through buf[off+n-1] contain the uncompressed data. The content of elements buf[off+n] through buf[off+len-1] is undefined, contrary to the specification of the InputStream superclass, so an implementation is free to modify these elements during the inflate operation. If this method returns -1 or throws an exception then the content of buf[off] through buf[off+len -1] is undefined.

Overrides:

read in class FilterInputStream

Parameters:

b - the buffer into which the data is read

off - the start offset in the destination array b

len - the maximum number of bytes read

Returns:

the actual number of bytes inflated, or -1 if the end of the compressed input is reached or a preset dictionary is needed

Throws:

NullPointerException - If b is null.

IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off

ZipException - if a ZIP format error has occurred

IOException - if an I/O error has occurred

See Also:

• FilterInputStream.in

available

public int available()
              throws IOException

Returns 0 after EOF has been reached, otherwise always return 1.

Programs should not count on this method to return the actual number of bytes that could be read without blocking.

Overrides:

available in class FilterInputStream

Returns:

1 before EOF and 0 after EOF.

Throws:

IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws IOException

Skips specified number of bytes of uncompressed data.

Overrides:

skip in class FilterInputStream

Parameters:

n - the number of bytes to skip

Returns:

the actual number of bytes skipped.

Throws:

IOException - if an I/O error has occurred

IllegalArgumentException - if n < 0

See Also:

• InputStream.skipNBytes(long)

close

public void close()
           throws IOException

Closes this input stream and releases any system resources associated with the stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterInputStream

Throws:

IOException - if an I/O error has occurred

See Also:

• FilterInputStream.in

fill

protected void fill()
             throws IOException

Fills input buffer with more data to decompress.

Implementation Requirements:

This method will read up to buf.length bytes into the input buffer, buf, starting at element 0. The len field will be set to the number of bytes read.

Throws:

IOException - if an I/O error has occurred

EOFException - if the end of input stream has been reached unexpectedly

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. The markSupported method of InflaterInputStream returns false.

Overrides:

markSupported in class FilterInputStream

Returns:

a boolean indicating if this stream type supports the mark and reset methods.

See Also:

• InputStream.mark(int)
• InputStream.reset()

mark

public void mark(int readlimit)

Marks the current position in this input stream.

Overrides:

mark in class FilterInputStream

Implementation Requirements:

The mark method of InflaterInputStream does nothing.

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

See Also:

• InputStream.reset()

reset

public void reset()
           throws IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

Overrides:

reset in class FilterInputStream

Implementation Requirements:

The method reset for class InflaterInputStream does nothing except throw an IOException.

Throws:

IOException - if this method is invoked.

See Also:

• InputStream.mark(int)
• IOException