Package org.apache.commons.compress.archivers

Class ArchiveOutputStream

java.lang.Object

java.io.OutputStream

org.apache.commons.compress.archivers.ArchiveOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

ArArchiveOutputStream, CpioArchiveOutputStream, TarArchiveOutputStream, ZipArchiveOutputStream

public abstract class ArchiveOutputStream
extends OutputStream

Archive output stream implementations are expected to override the OutputStream.write(byte[], int, int) method to improve performance. They should also override OutputStream.close() to ensure that any necessary trailers are added.

The normal sequence of calls when working with ArchiveOutputStreams is:

• Create ArchiveOutputStream object,
• optionally write SFX header (Zip only),
• repeat as needed:
  • putArchiveEntry(ArchiveEntry) (writes entry header),
  • OutputStream.write(byte[]) (writes entry data, as often as needed),
  • closeArchiveEntry() (closes entry),
• finish() (ends the addition of entries),
• optionally write additional data, provided format supports it,
• OutputStream.close().

Constructor Summary

Constructors

Constructor	Description
ArchiveOutputStream()

Method Summary

Modifier and Type	Method	Description
boolean	canWriteEntryData(ArchiveEntry archiveEntry)	Whether this stream is able to write the given entry.
abstract void	closeArchiveEntry()	Closes the archive entry, writing any trailer information that may be required.
abstract ArchiveEntry	createArchiveEntry(File inputFile, String entryName)	Create an archive entry using the inputFile and entryName provided.
ArchiveEntry	createArchiveEntry(Path inputPath, String entryName, LinkOption... options)	Create an archive entry using the inputPath and entryName provided.
abstract void	finish()	Finishes the addition of entries to this stream, without closing it.
long	getBytesWritten()	Returns the current number of bytes written to this stream.
int	getCount()	Deprecated. this method may yield wrong results for large archives, use #getBytesWritten instead
abstract void	putArchiveEntry(ArchiveEntry entry)	Writes the headers for an archive entry to the output stream.
void	write(int b)	Writes a byte to the current archive entry.

Methods inherited from class java.io.OutputStream

close, flush, nullOutputStream, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

ArchiveOutputStream

public ArchiveOutputStream()

Method Detail

putArchiveEntry

public abstract void putArchiveEntry(ArchiveEntry entry)
                              throws IOException

Writes the headers for an archive entry to the output stream. The caller must then write the content to the stream and call closeArchiveEntry() to complete the process.

Parameters:

entry - describes the entry

Throws:

IOException - if an I/O error occurs

closeArchiveEntry

public abstract void closeArchiveEntry()
                                throws IOException

Closes the archive entry, writing any trailer information that may be required.

Throws:

IOException - if an I/O error occurs

finish

public abstract void finish()
                     throws IOException

Finishes the addition of entries to this stream, without closing it. Additional data can be written, if the format supports it.

Throws:

IOException - if the user forgets to close the entry.

createArchiveEntry

public abstract ArchiveEntry createArchiveEntry(File inputFile,
                                                String entryName)
                                         throws IOException

Create an archive entry using the inputFile and entryName provided.

Parameters:

inputFile - the file to create the entry from

entryName - name to use for the entry

Returns:

the ArchiveEntry set up with details from the file

Throws:

IOException - if an I/O error occurs

createArchiveEntry

public ArchiveEntry createArchiveEntry(Path inputPath,
                                       String entryName,
                                       LinkOption... options)
                                throws IOException

Create an archive entry using the inputPath and entryName provided. The default implementation calls simply delegates as:

return createArchiveEntry(inputFile.toFile(), entryName);

Subclasses should override this method.

Parameters:

inputPath - the file to create the entry from

entryName - name to use for the entry

options - options indicating how symbolic links are handled.

Returns:

the ArchiveEntry set up with details from the file

Throws:

IOException - if an I/O error occurs

Since:

1.21

write

public void write(int b)
           throws IOException

Writes a byte to the current archive entry.

This method simply calls write( byte[], 0, 1 ).

MUST be overridden if the OutputStream.write(byte[], int, int) method is not overridden; may be overridden otherwise.

Specified by:

write in class OutputStream

Parameters:

b - The byte to be written.

Throws:

IOException - on error

getCount

@Deprecated
public int getCount()

Deprecated.

this method may yield wrong results for large archives, use #getBytesWritten instead

Returns the current number of bytes written to this stream.

Returns:

the number of written bytes

getBytesWritten

public long getBytesWritten()

Returns the current number of bytes written to this stream.

Returns:

the number of written bytes

Since:

1.1

canWriteEntryData

public boolean canWriteEntryData(ArchiveEntry archiveEntry)

Whether this stream is able to write the given entry.

Some archive formats support variants or details that are not supported (yet).

Parameters:

archiveEntry - the entry to test

Returns:

This implementation always returns true.

Since:

1.1