- Description
- Field Summary
- Constructor Summary
- Method Summary
- Field Details
- Constructor Details
- Method Details
Class ZipInputStream
Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown.
Reading Zip File Entries
The getNextEntry() method is used to read the next ZIP file entry (Local file (LOC) header record in the ZIP format) and position the stream at the entry's file data. The file data may read using one of the ZipInputStream read methods such as read or readAllBytes(). For example:-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intCentral directory (CEN) header internal file attributes field offset.static final intCentral directory (CEN) header external file attributes field offset.static final intCentral directory (CEN) header comment length field offset.static final intCentral directory (CEN) header uncompressed file crc-32 value field offset.static final intCentral directory (CEN) header disk number start field offset.static final intCentral directory (CEN) header extra field length field offset.static final intCentral directory (CEN) header encrypt, decrypt flags field offset.static final intCentral directory (CEN) header size in bytes (including signature).static final intCentral directory (CEN) header compression method field offset.static final intCentral directory (CEN) header uncompressed size field offset.static final intCentral directory (CEN) header filename length field offset.static final intCentral directory (CEN) header LOC header offset field offset.static final longCentral directory (CEN) header signature.static final intCentral directory (CEN) header compressed size field offset.static final intCentral directory (CEN) header modification time field offset.static final intCentral directory (CEN) header version made by field offset.static final intCentral directory (CEN) header version needed to extract field offset.static final intEnd of central directory (END) header ZIP file comment length field offset.static final intEnd of central directory (END) header size in bytes (including signature).static final intEnd of central directory (END) header offset for the first CEN header field offset.static final longEnd of central directory (END) header signature.static final intEnd of central directory (END) header central directory size in bytes field offset.static final intEnd of central directory (END) header number of entries on this disk field offset.static final intEnd of central directory (END) header total number of entries field offset.static final intExtra local (EXT) header uncompressed file crc-32 value field offset.static final intExtra local (EXT) header size in bytes (including signature).static final intExtra local (EXT) header uncompressed size field offset.static final longExtra local (EXT) header signature.static final intExtra local (EXT) header compressed size field offset.static final intLocal file (LOC) header uncompressed file crc-32 value field offset.static final intLocal file (LOC) header extra field length field offset.static final intLocal file (LOC) header general purpose bit flag field offset.static final intLocal file (LOC) header size in bytes (including signature).static final intLocal file (LOC) header compression method field offset.static final intLocal file (LOC) header uncompressed size field offset.static final intLocal file (LOC) header filename length field offset.static final longLocal file (LOC) header signature.static final intLocal file (LOC) header compressed size field offset.static final intLocal file (LOC) header modification time field offset.static final intLocal file (LOC) header version needed to extract field offset.Fields declared in class FilterInputStream
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Constructor Summary
ConstructorsConstructorDescriptionCreates a new ZIP input stream.Creates a new ZIP input stream. -
Method Summary
All MethodsInstance MethodsConcrete MethodsModifier and TypeMethodDescriptionintReturns 0 when end of stream is detected for the current ZIP entry or closeEntry() has been called on the current ZIP entry, otherwise returns 1.voidclose()Closes this input stream and releases any system resources associated with the stream.voidCloses the current ZIP entry and positions the stream for reading the next entry.protected ZipEntrycreateZipEntry(String name)Creates a new ZipEntry object for the specified entry name.Reads the next ZIP file entry and positions the stream at the beginning of the entry data.intread()Reads the next byte of data from the input stream for the current ZIP entry.intread(byte[] b, int off, int len)Reads the requested number of bytes from the input stream into the given byte array for the current ZIP entry returning the number of inflated bytes.byte[]Reads all remaining bytes from the input stream for the current ZIP entry.intreadNBytes(byte[] b, int off, int len)Reads the requested number of bytes from the input stream into the given byte array for the current ZIP entry returning the number of inflated bytes.byte[]readNBytes(int len)Reads up to a specified number of bytes from the input stream for the current ZIP entry.longskip(long n)Skips over and discards n bytes of data from this input stream for the current ZIP entry.voidskipNBytes(long n)Skips over and discards exactly n bytes of data from this input stream for the current ZIP entry.longtransferTo(OutputStream out)Reads all bytes from this input stream for the current ZIP entry and writes the bytes to the given output stream in the order that they are read.Methods declared in class InflaterInputStream
fill, mark, markSupported, resetModifier and TypeMethodDescriptionprotected voidfill()Fills input buffer with more data to decompress.voidmark(int readlimit)Marks the current position in this input stream.booleanTests if this input stream supports the mark and reset methods.voidreset()Repositions this stream to the position at the time the mark method was last called on this input stream.Methods declared in class FilterInputStream
readModifier and TypeMethodDescriptionintread(byte[] b)Reads up to b.length bytes of data from this input stream into an array of bytes.Methods declared in class InputStream
nullInputStreamModifier and TypeMethodDescriptionstatic InputStreamReturns a new InputStream that reads no bytes.Methods declared in class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitModifier and TypeMethodDescriptionprotected Objectclone()Creates and returns a copy of this object.booleanIndicates whether some other object is "equal to" this one.protected voidfinalize()Deprecated, for removal: This API element is subject to removal in a future version.Finalization is deprecated and subject to removal in a future release.final Class<?>getClass()Returns the runtime class of this Object.inthashCode()Returns a hash code value for this object.final voidnotify()Wakes up a single thread that is waiting on this object's monitor.final voidWakes up all threads that are waiting on this object's monitor.toString()Returns a string representation of the object.final voidwait()Causes the current thread to wait until it is awakened, typically by being notified or interrupted.final voidwait(long timeoutMillis)Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.final voidwait(long timeoutMillis, int nanos)Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
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Field Details
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LOCSIG
static final long LOCSIGLocal file (LOC) header signature.See Also: -
EXTSIG
static final long EXTSIGExtra local (EXT) header signature.See Also: -
CENSIG
static final long CENSIGCentral directory (CEN) header signature.See Also: -
ENDSIG
static final long ENDSIGEnd of central directory (END) header signature.See Also: -
LOCHDR
static final int LOCHDRLocal file (LOC) header size in bytes (including signature).See Also: -
EXTHDR
static final int EXTHDRExtra local (EXT) header size in bytes (including signature).See Also: -
CENHDR
static final int CENHDRCentral directory (CEN) header size in bytes (including signature).See Also: -
ENDHDR
static final int ENDHDREnd of central directory (END) header size in bytes (including signature).See Also: -
LOCVER
static final int LOCVERLocal file (LOC) header version needed to extract field offset.See Also: -
LOCFLG
static final int LOCFLGLocal file (LOC) header general purpose bit flag field offset.See Also: -
LOCHOW
static final int LOCHOWLocal file (LOC) header compression method field offset.See Also: -
LOCTIM
static final int LOCTIMLocal file (LOC) header modification time field offset.See Also: -
LOCCRC
static final int LOCCRCLocal file (LOC) header uncompressed file crc-32 value field offset.See Also: -
LOCSIZ
static final int LOCSIZLocal file (LOC) header compressed size field offset.See Also: -
LOCLEN
static final int LOCLENLocal file (LOC) header uncompressed size field offset.See Also: -
LOCNAM
static final int LOCNAMLocal file (LOC) header filename length field offset.See Also: -
LOCEXT
static final int LOCEXTLocal file (LOC) header extra field length field offset.See Also: -
EXTCRC
static final int EXTCRCExtra local (EXT) header uncompressed file crc-32 value field offset.See Also: -
EXTSIZ
static final int EXTSIZExtra local (EXT) header compressed size field offset.See Also: -
EXTLEN
static final int EXTLENExtra local (EXT) header uncompressed size field offset.See Also: -
CENVEM
static final int CENVEMCentral directory (CEN) header version made by field offset.See Also: -
CENVER
static final int CENVERCentral directory (CEN) header version needed to extract field offset.See Also: -
CENFLG
static final int CENFLGCentral directory (CEN) header encrypt, decrypt flags field offset.See Also: -
CENHOW
static final int CENHOWCentral directory (CEN) header compression method field offset.See Also: -
CENTIM
static final int CENTIMCentral directory (CEN) header modification time field offset.See Also: -
CENCRC
static final int CENCRCCentral directory (CEN) header uncompressed file crc-32 value field offset.See Also: -
CENSIZ
static final int CENSIZCentral directory (CEN) header compressed size field offset.See Also: -
CENLEN
static final int CENLENCentral directory (CEN) header uncompressed size field offset.See Also: -
CENNAM
static final int CENNAMCentral directory (CEN) header filename length field offset.See Also: -
CENEXT
static final int CENEXTCentral directory (CEN) header extra field length field offset.See Also: -
CENCOM
static final int CENCOMCentral directory (CEN) header comment length field offset.See Also: -
CENDSK
static final int CENDSKCentral directory (CEN) header disk number start field offset.See Also: -
CENATT
static final int CENATTCentral directory (CEN) header internal file attributes field offset.See Also: -
CENATX
static final int CENATXCentral directory (CEN) header external file attributes field offset.See Also: -
CENOFF
static final int CENOFFCentral directory (CEN) header LOC header offset field offset.See Also: -
ENDSUB
static final int ENDSUBEnd of central directory (END) header number of entries on this disk field offset.See Also: -
ENDTOT
static final int ENDTOTEnd of central directory (END) header total number of entries field offset.See Also: -
ENDSIZ
static final int ENDSIZEnd of central directory (END) header central directory size in bytes field offset.See Also: -
ENDOFF
static final int ENDOFFEnd of central directory (END) header offset for the first CEN header field offset.See Also: -
ENDCOM
static final int ENDCOMEnd of central directory (END) header ZIP file comment length field offset.See Also:
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Constructor Details
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ZipInputStream
Creates a new ZIP input stream.Parameters: in - the actual input streamThe UTF-8 charset is used to decode the entry names.
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ZipInputStream
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
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Method Details
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getNextEntry
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
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
Returns 0 when end of stream is detected for the current ZIP entry or closeEntry() has been called on the current ZIP entry, otherwise returns 1.Overrides: available in class InflaterInputStream Returns: 0 when end of stream is detected for the current ZIP entry or closeEntry() has been called on the current ZIP entry, otherwise 1. Throws: IOException - if an I/O error occurs.Programs should not count on this method to return the actual number of bytes that could be read without blocking.
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read
Reads the next byte of data from the input stream for the current ZIP entry. This method will block until enough input is available for decompression.Overrides: read in class InflaterInputStream Returns: the byte read, or -1 if the end of the stream is reached Throws: IOException - if an I/O error has occurred See Also: -
readAllBytes
Reads all remaining bytes from the input stream for the current ZIP entry. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream.Overrides: readAllBytes in class InputStream Returns: a byte array containing the bytes read from this input stream Throws: OutOfMemoryError - if an array of the required size cannot be allocated. IOException - if an I/O error occurs Since: 9When this stream reaches end of stream, further invocations of this method will return an empty byte array.
Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data.
If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently, the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
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readNBytes
Reads up to a specified number of bytes from the input stream for the current ZIP entry. This method blocks until the requested number of bytes has been read, end of stream is detected, or an exception is thrown. This method does not close the input stream.Overrides: readNBytes in class InputStream Implementation Note: This method calls super.readNBytes(int len). Parameters: len - the maximum number of bytes to read Returns: a byte array containing the bytes read from this input stream Throws: OutOfMemoryError - if an array of the required size cannot be allocated. IOException - if an I/O error occurs Since: 11The length of the returned array equals the number of bytes read from the stream. If len is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to len bytes are read from the stream. Fewer than len bytes may be read if end of stream is encountered.
When this stream reaches end of stream, further invocations of this method will return an empty byte array.
Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by len. Therefore, the method may be safely called with very large values of len provided sufficient memory is available.
If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently, the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
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readNBytes
Reads the requested number of bytes from the input stream into the given byte array for the current ZIP entry returning the number of inflated bytes. This method blocks until len bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream.Overrides: readNBytes in class InputStream Parameters: b - the byte array into which the data is read off - the start offset in b at which the data is written len - the maximum number of bytes to read Returns: the actual number of bytes read into the buffer Throws: IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off IOException - if an I/O error occurs Since: 9In the case where end of stream is reached before len bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero.
If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read up to len bytes.
The first byte read is stored into element b[off], the next one in to b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k ] through b[off+len-1] unaffected.
If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of b have been updated with data from the input stream. Consequently, the input stream and b may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
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skipNBytes
Skips over and discards exactly n bytes of data from this input stream for the current ZIP entry. If n is zero, then no bytes are skipped. If n is negative, then no bytes are skipped. Subclasses may handle the negative value differently.Overrides: skipNBytes in class InputStream Parameters: n - the number of bytes to be skipped. Throws: IOException - if the stream cannot be positioned properly or if an I/O error occurs. Since: 12 See Also:This method blocks until the requested number of bytes has been skipped, end of file is reached, or an exception is thrown.
If end of stream is reached before the stream is at the desired position, then an EOFException is thrown.
If an I/O error occurs, then the input stream may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
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transferTo
Reads all bytes from this input stream for the current ZIP entry and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream.Overrides: transferTo in class InputStream Parameters: out - the output stream, non-null Returns: the number of bytes transferred Throws: IOException - if an I/O error occurs when reading or writing Since: 9This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is asynchronously closed, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified.
If the total number of bytes transferred is greater than Long.MAX_VALUE, then Long.MAX_VALUE will be returned.
If an I/O error occurs reading from the input stream or writing to the output stream, then it may do so after some bytes have been read or written. Consequently, the input stream may not be at end of stream and one, or both, streams may be in an inconsistent state. It is strongly recommended that both streams be promptly closed if an I/O error occurs.
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read
Reads the requested number of bytes from the input stream into the given byte array for the current ZIP entry returning the number of inflated 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: 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:If the current entry is compressed and 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.
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skip
Skips over and discards n bytes of data from this input stream for 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
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
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