Package org.apache.poi.openxml4j.util

Class ZipInputStreamZipEntrySource

java.lang.Object

org.apache.poi.openxml4j.util.ZipInputStreamZipEntrySource

All Implemented Interfaces:

Closeable, AutoCloseable, ZipEntrySource

public class ZipInputStreamZipEntrySource
extends Object
implements ZipEntrySource

Provides a way to get at all the ZipEntries from a ZipInputStream, as many times as required. Allows a ZipInputStream to be treated much like a ZipFile, for a price in terms of memory. Be sure to call close() as soon as you're done, to free up that memory!

Constructor Summary

Constructors

Constructor	Description
ZipInputStreamZipEntrySource(ZipArchiveThresholdInputStream inp)	Reads all the entries from the ZipInputStream into memory, and don't close (since POI 4.0.1) the source stream.

Method Summary

Modifier and Type	Method	Description
void	close()	Indicates we are done with reading, and resources may be freed
Enumeration<? extends ZipArchiveEntry>	getEntries()	Returns an Enumeration of all the Entries
ZipArchiveEntry	getEntry(String path)	Return an entry by its path
InputStream	getInputStream(ZipArchiveEntry zipEntry)	Returns an InputStream of the decompressed data that makes up the entry
static int	getThresholdBytesForTempFiles()	Get the threshold at which it a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead (defaults to -1 meaning temp files are not used)
boolean	isClosed()	Has close been called already?
static void	setEncryptTempFiles(boolean encrypt)	Encrypt temp files when they are used.
static void	setThresholdBytesForTempFiles(int thresholdBytes)	Set the threshold at which a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead
static boolean	shouldEncryptTempFiles()	Whether temp files should be encrypted (default false).

Methods inherited from class java.lang.Object

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

Constructor Details

ZipInputStreamZipEntrySource

public ZipInputStreamZipEntrySource(ZipArchiveThresholdInputStream inp)
                             throws IOException

Reads all the entries from the ZipInputStream into memory, and don't close (since POI 4.0.1) the source stream. We'll then eat lots of memory, but be able to work with the entries at-will.

Throws:

IOException

See Also:

• setThresholdBytesForTempFiles(int)

Method Details

setThresholdBytesForTempFiles

public static void setThresholdBytesForTempFiles(int thresholdBytes)

Set the threshold at which a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead

Parameters:

thresholdBytes - number of bytes at which a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead - defaults to -1 meaning temp files are not used and that zip entries with more than 2GB of data after decompressing will fail, 0 means all zip entries are stored in temp files. A threshold like 50000000 (approx 50Mb is recommended)

Since:

POI 5.1.0

See Also:

• setEncryptTempFiles(boolean)

getThresholdBytesForTempFiles

public static int getThresholdBytesForTempFiles()

Get the threshold at which it a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead (defaults to -1 meaning temp files are not used)

Returns:

threshold in bytes

Since:

POI 5.1.0

setEncryptTempFiles

public static void setEncryptTempFiles(boolean encrypt)

Encrypt temp files when they are used. Only affects temp files related to zip entries.

Parameters:

encrypt - whether temp files should be encrypted

Since:

POI 5.1.0

See Also:

• setThresholdBytesForTempFiles(int)

shouldEncryptTempFiles

public static boolean shouldEncryptTempFiles()

Whether temp files should be encrypted (default false). Only affects temp files related to zip entries.

Since:

POI 5.1.0

getEntries

public Enumeration<? extends ZipArchiveEntry> getEntries()

Description copied from interface: ZipEntrySource

Returns an Enumeration of all the Entries

Specified by:

getEntries in interface ZipEntrySource

getInputStream

public InputStream getInputStream(ZipArchiveEntry zipEntry)
                           throws IOException

Description copied from interface: ZipEntrySource

Returns an InputStream of the decompressed data that makes up the entry

Specified by:

getInputStream in interface ZipEntrySource

Throws:

IOException

close

public void close()
           throws IOException

Description copied from interface: ZipEntrySource

Indicates we are done with reading, and resources may be freed

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface ZipEntrySource

Throws:

IOException

isClosed

public boolean isClosed()

Description copied from interface: ZipEntrySource

Has close been called already?

Specified by:

isClosed in interface ZipEntrySource

getEntry

public ZipArchiveEntry getEntry(String path)

Description copied from interface: ZipEntrySource

Return an entry by its path

Specified by:

getEntry in interface ZipEntrySource

Parameters:

path - the path in unix-notation

Returns:

the entry or null if not found