com.mucommander.file
Class AbstractRWArchiveFile

java.lang.Object
  com.mucommander.file.AbstractFile
      com.mucommander.file.impl.ProxyFile
          com.mucommander.file.AbstractArchiveFile
              com.mucommander.file.AbstractRWArchiveFile

All Implemented Interfaces:

PermissionAccesses, PermissionTypes

Direct Known Subclasses:

ZipArchiveFile

public abstract class AbstractRWArchiveFile
extends AbstractArchiveFile

AbstractRWArchiveFile represents a read-write archive file. This class is abstract and implemented by all read-write archive files. In addition to the read-only operations defined by AbstractArchiveFile, it provides abstract methods for adding and deleting entries from the archive. The isWritableArchive() method impletemented by this class always returns true. However, write operations may not always be available depending on the underlying file (e.g. if random file access is required). In that case, isWritableArchive() should be overridden to return true only when write operations are available.

Author:

Maxence Bernard

Field Summary

Fields inherited from class com.mucommander.file.AbstractArchiveFile

entryTreeDate, entryTreeRoot

Fields inherited from class com.mucommander.file.impl.ProxyFile

file

Fields inherited from class com.mucommander.file.AbstractFile

DEFAULT_SEPARATOR, fileURL, IO_BUFFER_SIZE, MUST_HINT, MUST_NOT_HINT, SHOULD_HINT, SHOULD_NOT_HINT, windowsDriveRootPattern

Fields inherited from interface com.mucommander.file.PermissionTypes

EXECUTE_PERMISSION, READ_PERMISSION, WRITE_PERMISSION

Fields inherited from interface com.mucommander.file.PermissionAccesses

GROUP_ACCESS, OTHER_ACCESS, USER_ACCESS

Constructor Summary

protected

AbstractRWArchiveFile(AbstractFile file) Creates an AbstractRWArchiveFile on top of the given file.

Method Summary

abstract java.io.OutputStream	addEntry(ArchiveEntry entry) Adds the given entry to the archive and returns an OutputStream to write the entry's contents if the entry is a regular file, null if the entry is a directory.
abstract void	deleteEntry(ArchiveEntry entry) Deletes the specified entry from the archive.
boolean	isWritableArchive() Returns true: AbstractRWArchiveFile implementations are capable of adding or deleting entries.
abstract void	optimizeArchive() Processes the archive file to leave it in an optimal form.
abstract void	updateEntry(ArchiveEntry entry) Updates the specified entry in the archive with the attributes containted in the ArchiveEntry object.

Methods inherited from class com.mucommander.file.AbstractArchiveFile

addToEntriesTree, canRunProcess, checkEntriesTree, createEntriesTree, declareEntriesTreeUpToDate, getArchiveEntryFile, getArchiveEntryFile, getEntries, getEntryInputStream, getFreeSpace, isBrowsable, isDirectory, ls, ls, ls, ls, ls, removeFromEntriesTree, runProcess

Methods inherited from class com.mucommander.file.impl.ProxyFile

canChangeDate, canGetGroup, canGetOwner, changeDate, changePermission, changePermissions, copyStream, copyTo, delete, deleteRecursively, equals, exists, getAbsolutePath, getCanonicalFile, getCanonicalPath, getChangeablePermissions, getCopyToHint, getDate, getExtension, getGroup, getInputStream, getInputStream, getJavaNetURL, getMoveToHint, getName, getOutputStream, getOwner, getParent, getPermissions, getPermissionsString, getProxiedFile, getRandomAccessInputStream, getRandomAccessOutputStream, getRoot, getSeparator, getSize, getTotalSpace, getUnderlyingFileObject, getURL, hashCode, hasRandomAccessInputStream, hasRandomAccessOutputStream, importPermissions, importPermissions, isHidden, isRoot, isSymlink, mkdir, mkfile, moveTo, setParent, toString

Methods inherited from class com.mucommander.file.AbstractFile

addTrailingSeparator, calculateChecksum, calculateChecksum, calculateChecksum, changePermissions, checkCopyPrerequisites, copyRecursively, deleteRecursively, getAbsolutePath, getAncestor, getAncestor, getCanonicalPath, getChild, getDirectChild, getExtension, getIcon, getIcon, getNameWithoutExtension, getParentArchive, getParentSilently, getTopAncestor, hasAncestor, hasAncestor, isParentOf, mkdir, mkdirs, mkfile, removeTrailingSeparator

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractRWArchiveFile

protected AbstractRWArchiveFile(AbstractFile file)

Creates an AbstractRWArchiveFile on top of the given file.

Parameters:

file - the file on top of which to create the archive

Method Detail

isWritableArchive

public boolean isWritableArchive()

Returns true: AbstractRWArchiveFile implementations are capable of adding or deleting entries. This method should be overridden if the implementation is capable of providing write access only under certain conditions, for example if it requires random access to the proxied archive file which may not always be available depending on the udnderlying file. If that is the case, this method should return true only when all conditions for providing write operations are met.

Specified by:

isWritableArchive in class AbstractArchiveFile

Returns:

true

addEntry

public abstract java.io.OutputStream addEntry(ArchiveEntry entry)
                                       throws java.io.IOException

Adds the given entry to the archive and returns an OutputStream to write the entry's contents if the entry is a regular file, null if the entry is a directory. Throws an IOException if the entry already exists in the archive or if an I/O error occurs.

Parameters:

entry - the entry to add to the archive

Returns:

an OutputStream to write the entry's contents if the entry is a regular file, null if the entry is a directory

Throws:

java.io.IOException - if the entry already exists in the archive or if an I/O error occurs

deleteEntry

public abstract void deleteEntry(ArchiveEntry entry)
                          throws java.io.IOException

Deletes the specified entry from the archive. Throws an IOException if the entry doesn't exist in the archive or if an I/O error occurs.

Parameters:

entry - the entry to delete from the archive

Throws:

java.io.IOException - if the entry doesn't exist in the archive or if an I/O error occurs

updateEntry

public abstract void updateEntry(ArchiveEntry entry)
                          throws java.io.IOException

Updates the specified entry in the archive with the attributes containted in the ArchiveEntry object. Throws an IOException if the entry doesn't exist in the archive or if an I/O error occurs.

This methods can be used to update the entry's date and permissions for instance.

Parameters:

entry - the entry to update in the archive

Throws:

java.io.IOException - if the entry doesn't exist in the archive or if an I/O error occurs

optimizeArchive

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

Processes the archive file to leave it in an optimal form. This method should be called after a writable archive has been modified (entries added or removed).

The actual effect of this method on the archive file depends on the kind of archive. It may be implemented as a no-op if there is no use for it. To illustrate, in the case of a ZipArchiveFile, this method removes chunks of free space that are left when entries are deleted.

Throws:

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