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
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.
Unless otherwise noted, passing a null
argument to a constructor
or method in this class will cause a NullPointerException
to be
thrown.
- Since:
- 1.1
- See Also:
-
Field Summary
Modifier and TypeFieldDescriptionprotected byte[]
Input buffer for decompression.protected Inflater
Decompressor for this stream.protected int
The total number of bytes read into the input buffer.Fields declared in class java.io.FilterInputStream
in
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Constructor Summary
ConstructorDescriptionCreates 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 TypeMethodDescriptionint
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
Tests if this input stream supports themark
andreset
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 themark
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
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Field Details
-
inf
Decompressor for this stream. -
buf
protected byte[] bufInput buffer for decompression. -
len
protected int lenThe total number of bytes read into the input buffer.
-
-
Constructor Details
-
InflaterInputStream
Creates a new input stream with the specified decompressor and buffer size.- Parameters:
in
- the input streaminf
- the decompressor ("inflater")size
- the input buffer size- Throws:
IllegalArgumentException
- ifsize <= 0
-
InflaterInputStream
Creates a new input stream with the specified decompressor and a default buffer size.- Parameters:
in
- the input streaminf
- the decompressor ("inflater")
-
InflaterInputStream
Creates a new input stream with a default decompressor and buffer size.- Parameters:
in
- the input stream
-
-
Method Details
-
read
Reads a byte of uncompressed data. This method will block until enough input is available for decompression.- Overrides:
read
in classFilterInputStream
- Returns:
- the byte read, or -1 if end of compressed input is reached
- Throws:
IOException
- if an I/O error has occurred- See Also:
-
read
Reads uncompressed data into an array of bytes, returning the number of inflated bytes. Iflen
is not zero, the method will block until some input can be decompressed; otherwise, no bytes are read and0
is returned.If this method returns a nonzero integer n then
buf[off]
throughbuf[off+
n-1]
contain the uncompressed data. The content of elementsbuf[off+
n]
throughbuf[off+
len-1]
is undefined, contrary to the specification of theInputStream
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 ofbuf[off]
throughbuf[off+
len-1]
is undefined.- Overrides:
read
in classFilterInputStream
- Parameters:
b
- the buffer into which the data is readoff
- the start offset in the destination arrayb
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:
IndexOutOfBoundsException
- Ifoff
is negative,len
is negative, orlen
is greater thanb.length - off
ZipException
- if a ZIP format error has occurredIOException
- if an I/O error has occurred- See Also:
-
available
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 classFilterInputStream
- Returns:
- 1 before EOF and 0 after EOF.
- Throws:
IOException
- if an I/O error occurs.
-
skip
Skips specified number of bytes of uncompressed data. This method may block until the specified number of bytes are skipped or end of stream is reached.- Overrides:
skip
in classFilterInputStream
- Implementation Note:
- This method skips at most
Integer.MAX_VALUE
bytes. - Parameters:
n
- the number of bytes to skip. Ifn
is zero then no bytes are skipped.- Returns:
- the actual number of bytes skipped, which might be zero
- Throws:
IOException
- if an I/O error occurs or if this stream is already closedIllegalArgumentException
- ifn < 0
- See Also:
-
close
Closes this input stream and releases any system resources associated with the stream.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classFilterInputStream
- Throws:
IOException
- if an I/O error has occurred- See Also:
-
fill
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 element0
. Thelen
field will be set to the number of bytes read. - Throws:
IOException
- if an I/O error has occurredEOFException
- if the end of input stream has been reached unexpectedly
-
markSupported
public boolean markSupported()Tests if this input stream supports themark
andreset
methods. ThemarkSupported
method ofInflaterInputStream
returnsfalse
.- Overrides:
markSupported
in classFilterInputStream
- Returns:
- a
boolean
indicating if this stream type supports themark
andreset
methods. - See Also:
-
mark
public void mark(int readlimit) Marks the current position in this input stream.- Overrides:
mark
in classFilterInputStream
- Implementation Requirements:
- The
mark
method ofInflaterInputStream
does nothing. - Parameters:
readlimit
- the maximum limit of bytes that can be read before the mark position becomes invalid.- See Also:
-
reset
Repositions this stream to the position at the time themark
method was last called on this input stream.- Overrides:
reset
in classFilterInputStream
- Implementation Requirements:
- The method
reset
for classInflaterInputStream
does nothing except throw anIOException
. - Throws:
IOException
- if this method is invoked.- See Also:
-