java.lang.Object | |
↳ | java.util.zip.Inflater |
This class decompresses data that was compressed using the DEFLATE algorithm (see specification ).
It is usually more convenient to use
InflaterInputStream
.
To decompress an in-memory
byte[]
to another in-memory
byte[]
manually:
byte[] compressedBytes = ... int decompressedByteCount = ... // From your format's metadata. Inflater inflater = new Inflater(); inflater.setInput(compressedBytes, 0, compressedBytes.length); byte[] decompressedBytes = new byte[decompressedByteCount]; if (inflater.inflate(decompressedBytes) != decompressedByteCount) { throw new AssertionError(); } inflater.end();
In situations where you don't have all the input in one array (or have so much
input that you want to feed it to the inflater in chunks), it's possible to call
setInput(byte[])
repeatedly, but you're much better off using
InflaterInputStream
to handle all this for you.
If you don't know how big the decompressed data will be, you can call
inflate(byte[])
repeatedly on a temporary buffer, copying the bytes to a
ByteArrayOutputStream
,
but this is probably another sign you'd be better off using
InflaterInputStream
.
Public Constructors | |||||||||||
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This constructor creates an inflater that expects a header from the input
stream.
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This constructor allows to create an inflater that expects no header from
the input stream.
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Public Methods | |||||||||||
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Releases resources associated with this
Inflater
.
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Indicates if the
Inflater
has inflated the entire deflated
stream.
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Returns the
Adler32
checksum of the bytes inflated so far, or the
checksum of the preset dictionary if
needsDictionary()
returns true.
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Returns the total number of bytes read by the
Inflater
.
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Returns a the total number of bytes written by this
Inflater
.
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Returns the number of bytes of current input remaining to be read by this
inflater.
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Returns the total number of bytes of input read by this
Inflater
.
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Returns the total number of bytes written to the output buffer by this
Inflater
.
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Inflates up to
byteCount
bytes from the current input and stores them in
buf
starting at
offset
.
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Inflates bytes from the current input and stores them in
buf
.
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Returns true if the input bytes were compressed with a preset
dictionary.
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Returns true if
setInput(byte[])
must be called before inflation can continue.
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Resets this
Inflater
.
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Sets the preset dictionary to be used for inflation to a subsequence of
dictionary
starting at
offset
and continuing for
byteCount
bytes.
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Sets the preset dictionary to be used for inflation to
dictionary
.
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Sets the current input to to be decompressed.
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Sets the current input to to be decompressed.
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Protected Methods | |||||||||||
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Invoked when the garbage collector has detected that this instance is no longer reachable.
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[Expand]
Inherited Methods
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From class
java.lang.Object
|
This constructor creates an inflater that expects a header from the input
stream. Use
Inflater(boolean)
if the input comes without a ZLIB
header.
This constructor allows to create an inflater that expects no header from the input stream.
noHeader |
true
indicates that no ZLIB header comes with the
input.
|
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Releases resources associated with this
Inflater
. Any unused
input or output is discarded. This method should be called explicitly in
order to free native resources as soon as possible. After
end()
is
called, other methods will typically throw
IllegalStateException
.
Indicates if the
Inflater
has inflated the entire deflated
stream. If deflated bytes remain and
needsInput()
returns
true
this method will return
false
. This method should be
called after all deflated input is supplied to the
Inflater
.
true
if all input has been inflated,
false
otherwise.
Returns the
Adler32
checksum of the bytes inflated so far, or the
checksum of the preset dictionary if
needsDictionary()
returns true.
Returns the total number of bytes read by the
Inflater
. This
method is the same as
getTotalIn()
except that it returns a
long
value instead of an integer.
Returns a the total number of bytes written by this
Inflater
. This
method is the same as
getTotalOut
except it returns a
long
value instead of an integer.
Returns the number of bytes of current input remaining to be read by this inflater.
Returns the total number of bytes of input read by this
Inflater
. This
method is limited to 32 bits; use
getBytesRead()
instead.
Returns the total number of bytes written to the output buffer by this
Inflater
. The method is limited to 32 bits; use
getBytesWritten()
instead.
Inflates up to
byteCount
bytes from the current input and stores them in
buf
starting at
offset
.
DataFormatException |
if the underlying stream is corrupted or was not compressed
using a
Deflater
.
|
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Inflates bytes from the current input and stores them in
buf
.
buf | the buffer where decompressed data bytes are written. |
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DataFormatException |
if the underlying stream is corrupted or was not compressed
using a
Deflater
.
|
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Returns true if the input bytes were compressed with a preset
dictionary. This method should be called if the first call to
inflate(byte[])
returns 0,
to determine whether a dictionary is required. If so,
setDictionary(byte[])
should be called with the appropriate dictionary before calling
inflate
again. Use
getAdler()
to determine which dictionary is required.
Returns true if
setInput(byte[])
must be called before inflation can continue.
Resets this
Inflater
. Should be called prior to inflating a new
set of data.
Sets the preset dictionary to be used for inflation to a subsequence of
dictionary
starting at
offset
and continuing for
byteCount
bytes. See
needsDictionary()
for details.
Sets the preset dictionary to be used for inflation to
dictionary
.
See
needsDictionary()
for details.
Sets the current input to to be decompressed. This method should only be
called if
needsInput()
returns
true
.
Sets the current input to to be decompressed. This method should only be
called if
needsInput()
returns
true
.
Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.
Note that objects that override
finalize
are significantly more expensive than
objects that don't. Finalizers may be run a long time after the object is no longer
reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup.
Note also that finalizers are run on a single VM-wide finalizer thread,
so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary
for a class that has a native peer and needs to call a native method to destroy that peer.
Even then, it's better to provide an explicit
close
method (and implement
Closeable
), and insist that callers manually dispose of instances. This
works well for something like files, but less well for something like a
BigInteger
where typical calling code would have to deal with lots of temporaries. Unfortunately,
code that creates lots of temporaries is the worst kind of code from the point of view of
the single finalizer thread.
If you
must
use finalizers, consider at least providing your own
ReferenceQueue
and having your own thread process that queue.
Unlike constructors, finalizers are not automatically chained. You are responsible for
calling
super.finalize()
yourself.
Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.