java.util.zip

Class Zip64

java.lang.Object

java.util.zip.Zip64

public class Zip64
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static long	MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE The maximum supported entry / archive size for standard (non zip64) entries and archives.

Method Summary

Modifier and Type	Method and Description
static void	insertZip64ExtendedInfoToExtras(ZipEntry ze) Appends a zip64 extended info record to the extras contained in ze.
static java.util.zip.ZipFile.EocdRecord	parseZip64EocdRecord(RandomAccessFile raf, long eocdRecordOffset, int commentLength)
static long	parseZip64EocdRecordLocator(RandomAccessFile raf, long eocdOffset) Parses the zip64 end of central directory record locator.
static boolean	parseZip64ExtendedInfo(ZipEntry ze, boolean fromCentralDirectory) Parse the zip64 extended info record from the extras present in ze.
static void	refreshZip64ExtendedInfo(ZipEntry ze) Copy the size, compressed size and local header offset fields from ze to inside ze's extended info record.
static void	writeZip64EocdRecordAndLocator(ByteArrayOutputStream baos, long numEntries, long offset, long cDirSize)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE

public static final long MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE

The maximum supported entry / archive size for standard (non zip64) entries and archives.

See Also:

Constant Field Values

Method Detail

parseZip64EocdRecordLocator

public static long parseZip64EocdRecordLocator(RandomAccessFile raf,
                                               long eocdOffset)
                                        throws IOException

Parses the zip64 end of central directory record locator. The locator must be placed immediately before the end of central directory (eocd) record starting at eocdOffset. The position of the file cursor for raf after a call to this method is undefined an callers must reposition it after each call to this method.

Throws:

IOException

parseZip64EocdRecord

public static java.util.zip.ZipFile.EocdRecord parseZip64EocdRecord(RandomAccessFile raf,
                                                                    long eocdRecordOffset,
                                                                    int commentLength)
                                                             throws IOException

Throws:

IOException

parseZip64ExtendedInfo

public static boolean parseZip64ExtendedInfo(ZipEntry ze,
                                             boolean fromCentralDirectory)
                                      throws ZipException

Parse the zip64 extended info record from the extras present in ze. If fromCentralDirectory is true, we assume we're parsing a central directory record. We assume a local file header otherwise. The difference between the two is that a central directory entry is required to be complete, whereas a local file header isn't. This is due to the presence of an optional data descriptor after the file content.

Returns:

true iff. a zip64 extended info record was found.

Throws:

ZipException

insertZip64ExtendedInfoToExtras

public static void insertZip64ExtendedInfoToExtras(ZipEntry ze)
                                            throws ZipException

Appends a zip64 extended info record to the extras contained in ze. If ze contains no extras, a new extras array is created.

Throws:

ZipException

refreshZip64ExtendedInfo

public static void refreshZip64ExtendedInfo(ZipEntry ze)

Copy the size, compressed size and local header offset fields from ze to inside ze's extended info record. This is additional step is necessary when we could calculate the correct sizes only after writing out the entry. In this case, the local file header would not contain real sizes, and they would be present in the data descriptor and the central directory only. We choose the simplest strategy of always writing out the size, compressedSize and local header offset in all our Zip64 Extended info records.

writeZip64EocdRecordAndLocator

public static void writeZip64EocdRecordAndLocator(ByteArrayOutputStream baos,
                                                  long numEntries,
                                                  long offset,
                                                  long cDirSize)
                                           throws IOException

Throws:

IOException