org.apache.commons.compress.archivers.zip
Class ZipArchiveInputStream

java.lang.Object
  java.io.InputStream
      org.apache.commons.compress.archivers.ArchiveInputStream
          org.apache.commons.compress.archivers.zip.ZipArchiveInputStream

All Implemented Interfaces:

Closeable

Direct Known Subclasses:

JarArchiveInputStream

public class ZipArchiveInputStream
extends ArchiveInputStream

Implements an input stream that can read Zip archives.

Note that ZipArchiveEntry.getSize() may return -1 if the DEFLATE algorithm is used, as the size information is not available from the header.

The ZipFile class is preferred when reading from files.

As of Apache Commons Compress it transparently supports Zip64 extensions and thus individual entries and archives larger than 4 GB or with more than 65536 entries.

See Also:

ZipFile

This class is not thread-safe

Constructor Summary

ZipArchiveInputStream(InputStream inputStream)

ZipArchiveInputStream(InputStream inputStream, String encoding, boolean useUnicodeExtraFields)

ZipArchiveInputStream(InputStream inputStream, String encoding, boolean useUnicodeExtraFields, boolean allowStoredEntriesWithDataDescriptor)

Method Summary

boolean	canReadEntryData(ArchiveEntry ae) Whether this class is able to read the given entry.
void	close()
ArchiveEntry	getNextEntry() Returns the next Archive Entry in this Stream.
ZipArchiveEntry	getNextZipEntry()
static boolean	matches(byte[] signature, int length) Checks if the signature matches what is expected for a zip file.
int	read(byte[] buffer, int start, int length)
long	skip(long value) Skips over and discards value bytes of data from this input stream.

Methods inherited from class org.apache.commons.compress.archivers.ArchiveInputStream

count, count, getBytesRead, getCount, pushedBackBytes, read

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, reset

Methods inherited from class java.lang.Object

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

Constructor Detail

ZipArchiveInputStream

public ZipArchiveInputStream(InputStream inputStream)

ZipArchiveInputStream

public ZipArchiveInputStream(InputStream inputStream,
                             String encoding,
                             boolean useUnicodeExtraFields)

Parameters:

encoding - the encoding to use for file names, use null for the platform's default encoding

useUnicodeExtraFields - whether to use InfoZIP Unicode Extra Fields (if present) to set the file names.

ZipArchiveInputStream

public ZipArchiveInputStream(InputStream inputStream,
                             String encoding,
                             boolean useUnicodeExtraFields,
                             boolean allowStoredEntriesWithDataDescriptor)

Parameters:

encoding - the encoding to use for file names, use null for the platform's default encoding

useUnicodeExtraFields - whether to use InfoZIP Unicode Extra Fields (if present) to set the file names.

allowStoredEntriesWithDataDescriptor - whether the stream will try to read STORED entries that use a data descriptor

Since:

1.1

Method Detail

getNextZipEntry

public ZipArchiveEntry getNextZipEntry()
                                throws IOException

Throws:

IOException

getNextEntry

public ArchiveEntry getNextEntry()
                          throws IOException

Returns the next Archive Entry in this Stream.

Specified by:

getNextEntry in class ArchiveInputStream

Returns:

the next entry, or null if there are no more entries

Throws:

IOException - if the next entry could not be read

canReadEntryData

public boolean canReadEntryData(ArchiveEntry ae)

Whether this class is able to read the given entry.

May return false if it is set up to use encryption or a compression method that hasn't been implemented yet.

Overrides:

canReadEntryData in class ArchiveInputStream

Since:

1.1

read

public int read(byte[] buffer,
                int start,
                int length)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

skip

public long skip(long value)
          throws IOException

Skips over and discards value bytes of data from this input stream.

This implementation may end up skipping over some smaller number of bytes, possibly 0, if and only if it reaches the end of the underlying stream.

The actual number of bytes skipped is returned.

Overrides:

skip in class InputStream

Parameters:

value - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

IOException - - if an I/O error occurs.

IllegalArgumentException - - if value is negative.

matches

public static boolean matches(byte[] signature,
                              int length)

Checks if the signature matches what is expected for a zip file. Does not currently handle self-extracting zips which may have arbitrary leading content.

Parameters:

signature - the bytes to check

length - the number of bytes to check

Returns:

true, if this stream is a zip archive stream, false otherwise