de.schlichtherle.util.zip
Class BasicZipOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.FilterOutputStream
          de.schlichtherle.util.zip.BasicZipOutputStream

All Implemented Interfaces:

Closeable, Flushable

Direct Known Subclasses:

ZipOutputArchive, ZipOutputStream

public class BasicZipOutputStream
extends FilterOutputStream

This class is not intended for public use! The methods in this class are unsynchronized and entries/getEntry(java.lang.String) enumerate/return ZipEntry instances which are shared with this class rather than clones of them. This is used within TrueZIP in order to benefit from the slightly better performance.

Since:

TrueZIP 6.4

Version:

$Id: BasicZipOutputStream.java 5e709f50671d 2010/11/05 11:52:07 christian $

Author:

Christian Schlichtherle

See Also:

ZipOutputStream

Nested Class Summary

private static class

BasicZipOutputStream.ZipDeflater A Deflater which can be asked for its current deflation level and counts input and output data length as a long integer value.

Field Summary

private long	cdOffset Start of central directory.
private String	charset The charset to use for entry names and comments.
private boolean	closed
private String	comment The file comment.
private CRC32	crc CRC instance to avoid parsing DEFLATED data twice.
private long	dataStart Start of entry data.
private byte[]	dbuf This buffer holds deflated data for output.
private BasicZipOutputStream.ZipDeflater	def This instance is used for deflated output.
static String	DEFAULT_CHARSET The default character set used for entry names and comments in ZIP compatible files.
private boolean	deflate Whether or not we need to deflate the current entry.
private Map	entries The list of ZIP entries started to be written so far.
private ZipEntry	entry Current entry.
private boolean	finished
private short	method Default compression method for next entry.
private byte[]	sbuf

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

BasicZipOutputStream(OutputStream out)
Creates a new ZIP output stream decorating the given output stream, using the "UTF-8" charset.

BasicZipOutputStream(OutputStream out, String charset)
Creates a new ZIP output stream decorating the given output stream.

Method Summary

private static void	checkLocalFileHeaderData(ZipEntry entry)
void	close() Closes this output stream and releases any system resources associated with the stream.
void	closeEntry() Writes all necessary data for this entry to the underlying stream.
private void	deflate()
Enumeration	entries() Returns an enumeration of the ZIP entries written so far.
void	finish() Closes the current entry and writes the Central Directory to the underlying output stream.
String	getComment() Returns the file comment.
String	getEncoding() Returns the charset to use for filenames and the file comment.
ZipEntry	getEntry(String name) Returns the ZipEntry for the given name or null if no entry with that name exists.
int	getLevel() Returns the compression level currently used.
int	getMethod() Returns the default compression method for subsequent entries.
boolean	isBusy() Returns true if and only if this BasicZipOutputStream is currently writing a ZIP entry.
long	length() Returns the total number of (compressed) bytes this stream has written to the underlying stream.
void	putNextEntry(ZipEntry entry) Equivalent to putNextEntry(entry, true).
void	putNextEntry(ZipEntry entry, boolean deflate) Starts writing the next ZIP entry to the underlying stream.
void	setComment(String comment) Sets the file comment.
void	setLevel(int level) Sets the compression level for subsequent entries.
void	setMethod(int method) Sets the default compression method for subsequent entries.
int	size() Returns the number of ZIP entries written so far.
private static LEDataOutputStream	toLEDataOutputStream(OutputStream out)
void	write(byte[] b, int off, int len)
void	write(int b)
private void	writeCentralFileHeader(ZipEntry entry) Writes a Central File Header record.
private void	writeDataDescriptor()
private void	writeEndOfCentralDirectory() Writes the End Of Central Directory record.
private void	writeLocalFileHeader()

Methods inherited from class java.io.FilterOutputStream

flush, write

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CHARSET

public static final String DEFAULT_CHARSET

The default character set used for entry names and comments in ZIP compatible files. This is "UTF-8" for compatibility with Sun's JDK implementation. Note that you should use "IBM437" for ordinary ZIP files instead.

See Also:

Constant Field Values

charset

private final String charset

The charset to use for entry names and comments.

crc

private final CRC32 crc

CRC instance to avoid parsing DEFLATED data twice.

def

private final BasicZipOutputStream.ZipDeflater def

This instance is used for deflated output.

dbuf

private final byte[] dbuf

This buffer holds deflated data for output.

sbuf

private final byte[] sbuf

comment

private String comment

The file comment.

method

private short method

Default compression method for next entry.

entries

private final Map entries

The list of ZIP entries started to be written so far. Maps entry names to zip entries.

dataStart

private long dataStart

Start of entry data.

cdOffset

private long cdOffset

Start of central directory.

finished

private boolean finished

closed

private boolean closed

entry

private ZipEntry entry

Current entry.

deflate

private boolean deflate

Whether or not we need to deflate the current entry. This can be used together with the DEFLATED method to write already compressed entry data into the ZIP file.

Constructor Detail

BasicZipOutputStream

public BasicZipOutputStream(OutputStream out)
                     throws NullPointerException

Creates a new ZIP output stream decorating the given output stream, using the "UTF-8" charset.

Throws:

NullPointerException - If out is null.

BasicZipOutputStream

public BasicZipOutputStream(OutputStream out,
                            String charset)
                     throws NullPointerException,
                            UnsupportedEncodingException

Creates a new ZIP output stream decorating the given output stream.

Throws:

NullPointerException - If out or charset is null.

UnsupportedEncodingException - If charset is not supported by this JVM.

Method Detail

toLEDataOutputStream

private static LEDataOutputStream toLEDataOutputStream(OutputStream out)

getEncoding

public String getEncoding()

Returns the charset to use for filenames and the file comment.

size

public int size()

Returns the number of ZIP entries written so far.

entries

public Enumeration entries()

Returns an enumeration of the ZIP entries written so far. Note that the enumerated entries are shared with this class. It is illegal to put more entries into this ZIP output stream concurrently or modify the state of the enumerated entries.

getEntry

public ZipEntry getEntry(String name)

Returns the ZipEntry for the given name or null if no entry with that name exists. Note that the returned entry is shared with this class. It is illegal to change its state!

Parameters:

name - Name of the ZIP entry.

getComment

public String getComment()

Returns the file comment.

setComment

public void setComment(String comment)

Sets the file comment.

getLevel

public int getLevel()

Returns the compression level currently used.

setLevel

public void setLevel(int level)

Sets the compression level for subsequent entries.

getMethod

public int getMethod()

Returns the default compression method for subsequent entries. This property is only used if a ZipEntry does not specify a compression method.

See Also:

setMethod(int), ZipEntry.getMethod()

setMethod

public void setMethod(int method)

Sets the default compression method for subsequent entries. This property is only used if a ZipEntry does not specify a compression method.

Legal values are ZipEntry.STORED (uncompressed) and ZipEntry.DEFLATED (compressed). The initial value is ZipEntry.DEFLATED.

See Also:

getMethod(), ZipEntry.setMethod(int)

length

public long length()

Returns the total number of (compressed) bytes this stream has written to the underlying stream.

isBusy

public boolean isBusy()

Returns true if and only if this BasicZipOutputStream is currently writing a ZIP entry.

putNextEntry

public final void putNextEntry(ZipEntry entry)
                        throws IOException

Equivalent to putNextEntry(entry, true).

Throws:

IOException

putNextEntry

public void putNextEntry(ZipEntry entry,
                         boolean deflate)
                  throws IOException

Starts writing the next ZIP entry to the underlying stream. Note that if two or more entries with the same name are written consecutively to this stream, the last entry written will shadow all other entries, i.e. all of them are written to the ZIP compatible file (and hence require space), but only the last will be accessible from the central directory. This is unlike the genuine java.util.zip.ZipOutputStream which would throw a ZipException in this method when the second entry with the same name is to be written.

Parameters:

entry - The ZIP entry to write.

deflate - Whether or not the entry data should be deflated. This should be set to false if and only if you are writing data which has been read from a ZIP archive file and has not been inflated again. The entries' properties CRC, compressed size and uncompressed size must be set appropriately.

Throws:

ZipException - If and only if writing the entry is impossible because the resulting file would not comply to the ZIP file format specification.

IOException - On any I/O related issue.

checkLocalFileHeaderData

private static void checkLocalFileHeaderData(ZipEntry entry)
                                      throws ZipException

Throws:

ZipException

writeLocalFileHeader

private void writeLocalFileHeader()
                           throws IOException

Throws:

IOException - On any I/O related issue.

write

public void write(int b)
           throws IOException

Overrides:

write in class FilterOutputStream

Throws:

IOException - On any I/O related issue.

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Overrides:

write in class FilterOutputStream

Throws:

IOException - On any I/O related issue.

deflate

private void deflate()
              throws IOException

Throws:

IOException

closeEntry

public void closeEntry()
                throws IOException

Writes all necessary data for this entry to the underlying stream.

Throws:

ZipException - If and only if writing the entry is impossible because the resulting file would not comply to the ZIP file format specification.

IOException - On any I/O related issue.

writeDataDescriptor

private void writeDataDescriptor()
                          throws IOException

Throws:

IOException - On any I/O related issue.

finish

public void finish()
            throws IOException

Closes the current entry and writes the Central Directory to the underlying output stream.

Notes:

• The underlying stream is not closed.
• Unlike Sun's implementation in J2SE 1.4.2, you may continue to use this ZIP output stream with putNextEntry(...) and the like. When you finally close the stream, the central directory will contain all entries written.

Throws:

ZipException - If and only if writing the entry is impossible because the resulting file would not comply to the ZIP file format specification.

IOException - On any I/O related issue.

writeCentralFileHeader

private void writeCentralFileHeader(ZipEntry entry)
                             throws IOException

Writes a Central File Header record.

Throws:

IOException - On any I/O related issue.

writeEndOfCentralDirectory

private void writeEndOfCentralDirectory()
                                 throws IOException

Writes the End Of Central Directory record.

Throws:

IOException - On any I/O related issue.

close

public void close()
           throws IOException

Closes this output stream and releases any system resources associated with the stream. This closes the open output stream writing to this ZIP file, if any.

Specified by:

close in interface Closeable

Overrides:

close in class FilterOutputStream

Throws:

IOException - On any I/O related issue.