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 | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
This constructor creates an inflater that expects a header from the input
stream.
| |||||||||||
This constructor allows to create an inflater that expects no header from
the input stream.
|
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Releases resources associated with this
Inflater . | |||||||||||
Indicates if the
Inflater has inflated the entire deflated
stream. | |||||||||||
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 . | |||||||||||
Returns a the total number of bytes written by this
Inflater . | |||||||||||
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 . | |||||||||||
Returns the total number of bytes written to the output buffer by this
Inflater . | |||||||||||
Inflates up to
byteCount bytes from the current input and stores them in
buf starting at offset . | |||||||||||
Inflates bytes from the current input and stores them in
buf . | |||||||||||
Returns true if the input bytes were compressed with a preset
dictionary.
| |||||||||||
Returns true if
setInput(byte[]) must be called before inflation can continue. | |||||||||||
Resets this
Inflater . | |||||||||||
Sets the preset dictionary to be used for inflation to a subsequence of
dictionary
starting at offset and continuing for byteCount bytes. | |||||||||||
Sets the preset dictionary to be used for inflation to
dictionary . | |||||||||||
Sets the current input to to be decompressed.
| |||||||||||
Sets the current input to to be decompressed.
|
Protected Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Invoked when the garbage collector has detected that this instance is no longer reachable.
|
[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.
|
---|
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 . |
---|
Inflates bytes from the current input and stores them in buf
.
buf | the buffer where decompressed data bytes are written. |
---|
DataFormatException | if the underlying stream is corrupted or was not compressed
using a Deflater .
|
---|
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.