Package org.apache.commons.compress.archivers

Class ArchiveOutputStream<E extends ArchiveEntry>

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

org.apache.commons.compress.CompressFilterOutputStream<java.io.OutputStream>

org.apache.commons.compress.archivers.ArchiveOutputStream<E>

Type Parameters:

E - The type of ArchiveEntry consumed.

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

Direct Known Subclasses:

ArArchiveOutputStream, CpioArchiveOutputStream, TarArchiveOutputStream, ZipArchiveOutputStream

public abstract class ArchiveOutputStream<E extends ArchiveEntry>
extends CompressFilterOutputStream<java.io.OutputStream>

Archive output stream implementations are expected to override the FilterOutputStream.write(byte[], int, int) method to improve performance. They should also override CompressFilterOutputStream.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),
  • FilterOutputStream.write(byte[]) (writes entry data, as often as needed),
  • closeArchiveEntry() (closes entry),
• CompressFilterOutputStream.finish() (ends the addition of entries),
• optionally write additional data, provided format supports it,
• CompressFilterOutputStream.close().

Constructor Summary

Constructors

Constructor	Description
ArchiveOutputStream()	Constructs a new instance without a backing OutputStream.
ArchiveOutputStream(java.io.OutputStream out)	Constructs a new instance with the given backing OutputStream.

Method Summary

Modifier and Type	Method	Description
boolean	canWriteEntryData(ArchiveEntry archiveEntry)	Tests 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 E	createArchiveEntry(java.io.File inputFile, java.lang.String entryName)	Creates an archive entry using the inputFile and entryName provided.
E	createArchiveEntry(java.nio.file.Path inputPath, java.lang.String entryName, java.nio.file.LinkOption... options)	Creates an archive entry using the inputPath and entryName provided.
long	getBytesWritten()	Gets 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(E 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 org.apache.commons.compress.CompressFilterOutputStream

close, finish, isClosed, write, write, writeUsAscii, writeUsAsciiRaw, writeUtf8

Methods inherited from class java.io.FilterOutputStream

flush, write, write

Methods inherited from class java.io.OutputStream

nullOutputStream

Methods inherited from class java.lang.Object

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

Constructor Detail

ArchiveOutputStream

public ArchiveOutputStream()

Constructs a new instance without a backing OutputStream.

You must initialize this.out after construction.

ArchiveOutputStream

public ArchiveOutputStream(java.io.OutputStream out)

Constructs a new instance with the given backing OutputStream.

Parameters:

out - the underlying output stream to be assigned to the field this.out for later use, or null if this instance is to be created without an underlying stream.

Since:

1.27.0.

Method Detail

canWriteEntryData

public boolean canWriteEntryData(ArchiveEntry archiveEntry)

Tests 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

closeArchiveEntry

public abstract void closeArchiveEntry()
                                throws java.io.IOException

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

Throws:

java.io.IOException - if an I/O error occurs

createArchiveEntry

public abstract E createArchiveEntry(java.io.File inputFile,
                                     java.lang.String entryName)
                              throws java.io.IOException

Creates 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:

java.io.IOException - if an I/O error occurs

createArchiveEntry

public E createArchiveEntry(java.nio.file.Path inputPath,
                            java.lang.String entryName,
                            java.nio.file.LinkOption... options)
                     throws java.io.IOException

Creates 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:

java.io.IOException - if an I/O error occurs

Since:

1.21

getBytesWritten

public long getBytesWritten()

Gets the current number of bytes written to this stream.

Returns:

the number of written bytes

Since:

1.1

getCount

@Deprecated
public int getCount()

Deprecated.

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

Gets the current number of bytes written to this stream.

Returns:

the number of written bytes

putArchiveEntry

public abstract void putArchiveEntry(E entry)
                              throws java.io.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:

java.io.IOException - if an I/O error occurs

write

public void write(int b)
           throws java.io.IOException

Writes a byte to the current archive entry.

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

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

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - The byte to be written.

Throws:

java.io.IOException - on error