ewe.zip
Class ZipOutputStream

java.lang.Object
  ewe.util.Errorable
      ewe.io.BasicStreamObject
          ewe.io.StreamObject
              ewe.zip.ZipOutputStream

All Implemented Interfaces:

BasicStream, Stream, Streamable, ZipConstants

public class ZipOutputStream

extends StreamObject

implements ZipConstants

This is a FilterOutputStream that writes the files into a zip archive one after another. It has a special method to start a new zip entry. The zip entries contains information about the file name size, compressed size, CRC, etc. It includes support for STORED and DEFLATED entries. This class is not thread safe.

Field Summary

static int	DEFLATED Compression method.
int	level
static int	STORED Compression method.

Fields inherited from class ewe.io.StreamObject

napIterations, napTime, READWRITE_CLOSED, READWRITE_ERROR, READWRITE_WOULDBLOCK

Fields inherited from class ewe.io.BasicStreamObject

closed

Fields inherited from class ewe.util.Errorable

error

Fields inherited from interface ewe.zip.ZipConstants

C_COMPRESSED_SIZE, C_COMPRESSION_METHOD, C_CRC32, C_DISK_NUMBER_START, C_EXTERNAL_FILE_ATTRIBUTES, C_EXTRA_FIELD_LENGTH, C_FILE_COMMENT_LENGTH, C_FILENAME_LENGTH, C_GENERAL_PURPOSE_BIT_FLAG, C_HDR_SIG, C_INTERNAL_FILE_ATTRIBUTES, C_LAST_MOD_FILE_DATE, C_LAST_MOD_FILE_TIME, C_RELATIVE_OFFSET_LOCAL_HEADER, C_SIGNATURE, C_SIZE, C_UNCOMPRESSED_SIZE, C_VERSION_MADE_BY, C_VERSION_NEEDED_TO_EXTRACT, D_COMPRESSED_SIZE, D_CRC32, D_HDR_SIG, D_SIGNATURE, D_SIZE, D_UNCOMPRESSED_SIZE, EC_HDR_SIG, EC_NUM_DISK_WITH_START_CENTRAL_DIR, EC_NUM_ENTRIES_CENTRL_DIR_THS_DISK, EC_NUMBER_THIS_DISK, EC_OFFSET_START_CENTRAL_DIRECTORY, EC_SIGNATURE, EC_SIZE, EC_SIZE_CENTRAL_DIRECTORY, EC_TOTAL_ENTRIES_CENTRAL_DIR, EC_ZIPFILE_COMMENT_LENGTH, L_COMPRESSED_SIZE, L_COMPRESSION_METHOD, L_CRC32, L_EXTRA_FIELD_LENGTH, L_FILENAME_LENGTH, L_GENERAL_PURPOSE_BIT_FLAG, L_HDR_SIG, L_LAST_MOD_FILE_DATE, L_LAST_MOD_FILE_TIME, L_SIGNATURE, L_SIZE, L_UNCOMPRESSED_SIZE, L_VERSION_NEEDED_TO_EXTRACT, Z_BEST_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_NO_COMPRESSION

Constructor Summary

ZipOutputStream(BasicStream out)
Creates a new Zip output stream, writing a zip archive.

Method Summary

boolean	closeEntry() Closes the current entry.
boolean	finish() Finishes the stream.
boolean	flushStream() This is non-blocking.
int	nonBlockingWrite(byte[] b, int off, int len) Writes the given buffer to the current entry.
boolean	putNextEntry(ZipEntry entry) Starts a new Zip entry.
boolean	setComment(String comment) Set the zip file comment.
void	setLevel(int level) Sets default compression level.
boolean	setMethod(int method) Sets default compression method.

Methods inherited from class ewe.io.StreamObject

close, closeStream, doRead, doWrite, flush, isOpen, nap, nap, nonBlockingRead, read, readAByte, readBytes, readBytes, write, writeAByte, writeBytes, writeBytes

Methods inherited from class ewe.io.BasicStreamObject

getException, getName, read, read, throwIOException, toInputStream, toOutputStream, toStream, write, write

Methods inherited from class ewe.util.Errorable

returnError, returnError, returnError

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, toString

Field Detail

STORED

public static final int STORED

Compression method. This method doesn't compress at all.

See Also:

Constant Field Values

DEFLATED

public static final int DEFLATED

Compression method. This method uses the Deflater.

See Also:

Constant Field Values

level

public int level

Constructor Detail

ZipOutputStream

public ZipOutputStream(BasicStream out)

Creates a new Zip output stream, writing a zip archive.

Parameters:

out - the output stream to which the zip archive is written.

Method Detail

setComment

public boolean setComment(String comment)

Set the zip file comment.

Parameters:

comment - the comment.

Throws:

IllegalArgumentException - if UTF8 encoding of comment is longer than 0xffff bytes.

setMethod

public boolean setMethod(int method)

Sets default compression method. If the Zip entry specifies another method its method takes precedence.

Parameters:

method - the method.

Throws:

IllegalArgumentException - if method is not supported.

See Also:

STORED, DEFLATED

setLevel

public void setLevel(int level)

Sets default compression level. The new level will be activated immediately.

Throws:

IllegalArgumentException - if level is not supported.

See Also:

Deflater

putNextEntry

public boolean putNextEntry(ZipEntry entry)

Starts a new Zip entry. It automatically closes the previous entry if present. If the compression method is stored, the entry must have a valid size and crc, otherwise all elements (except name) are optional, but must be correct if present. If the time is not set in the entry, the current time is used.

Parameters:

entry - the entry.

Throws:

IOException - if an I/O error occured.

IllegalStateException - if stream was finished

closeEntry

public boolean closeEntry()

Closes the current entry.

Throws:

IOException - if an I/O error occured.

IllegalStateException - if no entry is active.

nonBlockingWrite

public int nonBlockingWrite(byte[] b,
                            int off,
                            int len)

Writes the given buffer to the current entry.

Specified by:

nonBlockingWrite in interface BasicStream

Overrides:

nonBlockingWrite in class StreamObject

Parameters:

b - Source byte array holding data to be written.

off - Starting index in buff for data to be written.

len - Number of bytes to write - should never be zero.

Returns:

greater than 0 = Number of bytes actually written.
0 = No bytes could be written yet - but the stream is still open.
-1 = Stream has been closed - no further writes are possible.
-2 = IO error - something went wrong.
Note that these values are different to the Stream.writeBytes method.

Throws:

IOException - if an I/O error occured.

IllegalStateException - if no entry is active.

finish

public boolean finish()

Finishes the stream. This will write the central directory at the end of the zip file and flush the stream.

Throws:

IOException - if an I/O error occured.

flushStream

public boolean flushStream()
                    throws IOException

Description copied from interface: BasicStream

This is non-blocking. It returns true if the flush completed, false if it did not, or throws an exception on error.

Specified by:

flushStream in interface BasicStream

Throws:

IOException