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openjdk / 17 / java.base / java / util / zip / zipinputstream.html

Class ZipInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
java.util.zip.InflaterInputStream
java.util.zip.ZipInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
Direct Known Subclasses:
JarInputStream 
public class ZipInputStream extends InflaterInputStream
This class implements an input stream filter for reading files in the ZIP file format. Includes support for both compressed and uncompressed entries.
Since:
1.1

Field Summary

Modifier and Type Field Description
static final int CENATT
Central directory (CEN) header internal file attributes field offset.
static final int CENATX
Central directory (CEN) header external file attributes field offset.
static final int CENCOM
Central directory (CEN) header comment length field offset.
static final int CENCRC
Central directory (CEN) header uncompressed file crc-32 value field offset.
static final int CENDSK
Central directory (CEN) header disk number start field offset.
static final int CENEXT
Central directory (CEN) header extra field length field offset.
static final int CENFLG
Central directory (CEN) header encrypt, decrypt flags field offset.
static final int CENHDR
Central directory (CEN) header size in bytes (including signature).
static final int CENHOW
Central directory (CEN) header compression method field offset.
static final int CENLEN
Central directory (CEN) header uncompressed size field offset.
static final int CENNAM
Central directory (CEN) header filename length field offset.
static final int CENOFF
Central directory (CEN) header LOC header offset field offset.
static final long CENSIG
Central directory (CEN) header signature.
static final int CENSIZ
Central directory (CEN) header compressed size field offset.
static final int CENTIM
Central directory (CEN) header modification time field offset.
static final int CENVEM
Central directory (CEN) header version made by field offset.
static final int CENVER
Central directory (CEN) header version needed to extract field offset.
static final int ENDCOM
End of central directory (END) header zip file comment length field offset.
static final int ENDHDR
End of central directory (END) header size in bytes (including signature).
static final int ENDOFF
End of central directory (END) header offset for the first CEN header field offset.
static final long ENDSIG
End of central directory (END) header signature.
static final int ENDSIZ
End of central directory (END) header central directory size in bytes field offset.
static final int ENDSUB
End of central directory (END) header number of entries on this disk field offset.
static final int ENDTOT
End of central directory (END) header total number of entries field offset.
static final int EXTCRC
Extra local (EXT) header uncompressed file crc-32 value field offset.
static final int EXTHDR
Extra local (EXT) header size in bytes (including signature).
static final int EXTLEN
Extra local (EXT) header uncompressed size field offset.
static final long EXTSIG
Extra local (EXT) header signature.
static final int EXTSIZ
Extra local (EXT) header compressed size field offset.
static final int LOCCRC
Local file (LOC) header uncompressed file crc-32 value field offset.
static final int LOCEXT
Local file (LOC) header extra field length field offset.
static final int LOCFLG
Local file (LOC) header general purpose bit flag field offset.
static final int LOCHDR
Local file (LOC) header size in bytes (including signature).
static final int LOCHOW
Local file (LOC) header compression method field offset.
static final int LOCLEN
Local file (LOC) header uncompressed size field offset.
static final int LOCNAM
Local file (LOC) header filename length field offset.
static final long LOCSIG
Local file (LOC) header signature.
static final int LOCSIZ
Local file (LOC) header compressed size field offset.
static final int LOCTIM
Local file (LOC) header modification time field offset.
static final int LOCVER
Local file (LOC) header version needed to extract field offset.

Fields declared in class java.util.zip.InflaterInputStream

buf, inf, len

Fields declared in class java.io.FilterInputStream

in

Constructor Summary

Constructor Description
ZipInputStream(InputStream in)
Creates a new ZIP input stream.
ZipInputStream(InputStream in, Charset charset)
Creates a new ZIP input stream.

Method Summary

Modifier and Type Method Description
int available()
Returns 0 after EOF has reached for the current entry data, otherwise always return 1.
void close()
Closes this input stream and releases any system resources associated with the stream.
void closeEntry()
Closes the current ZIP entry and positions the stream for reading the next entry.
protected ZipEntry createZipEntry(String name)
Creates a new ZipEntry object for the specified entry name.
ZipEntry getNextEntry()
Reads the next ZIP file entry and positions the stream at the beginning of the entry data.
int read(byte[] b, int off, int len)
Reads from the current ZIP entry into an array of bytes.
long skip(long n)
Skips specified number of bytes in the current ZIP entry.

Methods declared in class java.util.zip.InflaterInputStream

fill, mark, markSupported, read, reset

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

LOCSIG

static final long LOCSIG
Local file (LOC) header signature.
See Also:

EXTSIG

static final long EXTSIG
Extra local (EXT) header signature.
See Also:

CENSIG

static final long CENSIG
Central directory (CEN) header signature.
See Also:

ENDSIG

static final long ENDSIG
End of central directory (END) header signature.
See Also:

LOCHDR

static final int LOCHDR
Local file (LOC) header size in bytes (including signature).
See Also:

EXTHDR

static final int EXTHDR
Extra local (EXT) header size in bytes (including signature).
See Also:

CENHDR

static final int CENHDR
Central directory (CEN) header size in bytes (including signature).
See Also:

ENDHDR

static final int ENDHDR
End of central directory (END) header size in bytes (including signature).
See Also:

LOCVER

static final int LOCVER
Local file (LOC) header version needed to extract field offset.
See Also:

LOCFLG

static final int LOCFLG
Local file (LOC) header general purpose bit flag field offset.
See Also:

LOCHOW

static final int LOCHOW
Local file (LOC) header compression method field offset.
See Also:

LOCTIM

static final int LOCTIM
Local file (LOC) header modification time field offset.
See Also:

LOCCRC

static final int LOCCRC
Local file (LOC) header uncompressed file crc-32 value field offset.
See Also:

LOCSIZ

static final int LOCSIZ
Local file (LOC) header compressed size field offset.
See Also:

LOCLEN

static final int LOCLEN
Local file (LOC) header uncompressed size field offset.
See Also:

LOCNAM

static final int LOCNAM
Local file (LOC) header filename length field offset.
See Also:

LOCEXT

static final int LOCEXT
Local file (LOC) header extra field length field offset.
See Also:

EXTCRC

static final int EXTCRC
Extra local (EXT) header uncompressed file crc-32 value field offset.
See Also:

EXTSIZ

static final int EXTSIZ
Extra local (EXT) header compressed size field offset.
See Also:

EXTLEN

static final int EXTLEN
Extra local (EXT) header uncompressed size field offset.
See Also:

CENVEM

static final int CENVEM
Central directory (CEN) header version made by field offset.
See Also:

CENVER

static final int CENVER
Central directory (CEN) header version needed to extract field offset.
See Also:

CENFLG

static final int CENFLG
Central directory (CEN) header encrypt, decrypt flags field offset.
See Also:

CENHOW

static final int CENHOW
Central directory (CEN) header compression method field offset.
See Also:

CENTIM

static final int CENTIM
Central directory (CEN) header modification time field offset.
See Also:

CENCRC

static final int CENCRC
Central directory (CEN) header uncompressed file crc-32 value field offset.
See Also:

CENSIZ

static final int CENSIZ
Central directory (CEN) header compressed size field offset.
See Also:

CENLEN

static final int CENLEN
Central directory (CEN) header uncompressed size field offset.
See Also:

CENNAM

static final int CENNAM
Central directory (CEN) header filename length field offset.
See Also:

CENEXT

static final int CENEXT
Central directory (CEN) header extra field length field offset.
See Also:

CENCOM

static final int CENCOM
Central directory (CEN) header comment length field offset.
See Also:

CENDSK

static final int CENDSK
Central directory (CEN) header disk number start field offset.
See Also:

CENATT

static final int CENATT
Central directory (CEN) header internal file attributes field offset.
See Also:

CENATX

static final int CENATX
Central directory (CEN) header external file attributes field offset.
See Also:

CENOFF

static final int CENOFF
Central directory (CEN) header LOC header offset field offset.
See Also:

ENDSUB

static final int ENDSUB
End of central directory (END) header number of entries on this disk field offset.
See Also:

ENDTOT

static final int ENDTOT
End of central directory (END) header total number of entries field offset.
See Also:

ENDSIZ

static final int ENDSIZ
End of central directory (END) header central directory size in bytes field offset.
See Also:

ENDOFF

static final int ENDOFF
End of central directory (END) header offset for the first CEN header field offset.
See Also:

ENDCOM

static final int ENDCOM
End of central directory (END) header zip file comment length field offset.
See Also:

Constructor Details

ZipInputStream

public ZipInputStream(InputStream in)
Creates a new ZIP input stream.

The UTF-8 charset is used to decode the entry names.

Parameters:
in - the actual input stream

ZipInputStream

public ZipInputStream(InputStream in, Charset charset)
Creates a new ZIP input stream.
Parameters:
in - the actual input stream
charset - The charset to be used to decode the ZIP entry name (ignored if the language encoding bit of the ZIP entry's general purpose bit flag is set).
Since:
1.7

Method Details

getNextEntry

public ZipEntry getNextEntry() throws IOException
Reads the next ZIP file entry and positions the stream at the beginning of the entry data.
Returns:
the next ZIP file entry, or null if there are no more entries
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O error has occurred

closeEntry

public void closeEntry() throws IOException
Closes the current ZIP entry and positions the stream for reading the next entry.
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O error has occurred

available

public int available() throws IOException
Returns 0 after EOF has reached for the current entry data, 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 InflaterInputStream
Returns:
1 before EOF and 0 after EOF has reached for current entry.
Throws:
IOException - if an I/O error occurs.

read

public int read(byte[] b, int off, int len) throws IOException
Reads from the current ZIP entry into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.
Overrides:
read in class InflaterInputStream
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 read, or -1 if the end of the entry is reached
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 file error has occurred
IOException - if an I/O error has occurred
See Also:

skip

public long skip(long n) throws IOException
Skips specified number of bytes in the current ZIP entry.
Overrides:
skip in class InflaterInputStream
Parameters:
n - the number of bytes to skip
Returns:
the actual number of bytes skipped
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O error has occurred
IllegalArgumentException - if n < 0
See Also:

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 InflaterInputStream
Throws:
IOException - if an I/O error has occurred
See Also:

createZipEntry

protected ZipEntry createZipEntry(String name)
Creates a new ZipEntry object for the specified entry name.
Parameters:
name - the ZIP file entry name
Returns:
the ZipEntry just created

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/zip/ZipInputStream.html