com.togethersoft.openapi.vfs
Interface VirtualFile

public interface VirtualFile

extends PropertyMap

This class represents a file (or directory) of VirtualFileSystem. Like java.io.File, the instance of
VirtualFile can correspond to unexistent file. Files of VFS are cached and not necessarily are written or even
exists on disk. Different instances of VirtualFile can represent same file.
Each instance has a Context; however the contexts are not used currently.

VirtualFile has a number of properties. Custom properties are not supported now. The predefined properties
are listed in VirtualFileProperty.

Author:

TogetherSoft

Method Detail

addVirtualFileListener

public void addVirtualFileListener(VirtualFileListener listener, int depth)

Adds VirtualFileListener to a file

public VirtualFileEnumeration children()
                                 throws java.io.IOException

Returns children of invoking VirtualFile, which must be directory. Children are returned as enumeration of
VirtualFiles. The child can exists either on disk or in memory.

Returns: enumerations of all created files in directory.

Throws:

IOException when list of children cannot be obtained. Eg, when this
isn't directory at all.

public VirtualFileEnumeration children(VirtualFileFilter filter)
                                 throws java.io.IOException

Extension of children (UnatyPredicate). The child will be included in childlist only if
filer.accept(VirtualFile) method returns true.

Returns: enumerations of all created files in directory.

Throws:

IOException when list of children cannot be obtained. Eg, when this isn't directory.

public VirtualFile copy(VirtualFile newParent, boolean overwrite)
                  throws java.io.IOException

Copies VirtualFile to another directory.
See comments for move(...) method.

Parameters:

newParent destination directory;

overwrite specifies, if existent file can be overwritten;

Returns: VirtualFile of copied file.

Throws:

IOException if copying was unsuccessful.

public void create(VirtualFileType fileType, boolean overwrite)
             throws java.io.IOException

Creates file or directory if it didn't exist yet.
Currently file is physically created at the same time it is created in VFS.

Parameters:

overwrite specifies, if existent file should be overwritten

Throws:

IOException if file wasn't created for any reason.

public void delete()
             throws java.io.IOException

Deletes file from memory and disk. If applied to directory, deletes whole branch silently. If operation was successful,
VirtualFile became unexistent, i.e. exists method returns false.

public void discardCache()
                   throws java.io.IOException

Discards any changes made to cache but do not reload file from disk.

public void discardCache(Depth depth)
                   throws java.io.IOException

Discards any changes made to cache but do not reload file from disk.

Bugs:

1. Some manipulations with archive files can cause StackOverflowError in this method with depth == Depth.INFINITY .
   

Parameters:

depth defines, if the command should be recursive.

public boolean exists()

Returns true if the file exists either on disk or in memory.

public void externalUpdate(Depth depth)
                     throws java.io.IOException

Not supported now Checks timestamps of file(s) on disk and (re)load their contents if file(s) were updated.
Simultanious modification file in memory and on disk causes conflict, which is solved by mean of
VirtualFileErrorUI

Parameters:

depth defines, if the command should be recursive.

public byte[] getArrayOfBytes()
                        throws java.io.IOException

Reads the whole file, saving cache if needed, and returns the read array of bytes.
Notice, that in current realization returned value can (or cannot) be reference to the very VFS file cache
so modification of this array may cause file cache modification.

Returns: contents of file as array of bytes

Throws:

IOException when applied to directory.

public VirtualFile getChild(String shortName)

Does exactly the same as VirtualFileManager method getVirtualFile(VirtualFile parent, String
relativePath, VirtualFileContext context), but with default context.

public VirtualFileContext getContext()

Return instnace of Context, assigned to this VirtualFile

public String getExtension()

public String getFullName()

Shortcut for FILE_FULL_NAME property getting.

public InputStream getInputStream()
                            throws java.io.IOException

Returns: InputStream which can be used to read file contents.

Throws:

IOException when applied to directory.

public OutputStream getOutputStream()
                              throws java.io.IOException

Returns output stream. It should be closed in order to allow flushing. Opened stream always works for
rewriting file content.

Throws:

IOException when applied to directory.

public VirtualFile getParent()

Returns: VirtualFile for parent directory or null when applied to root directory.

public String getPathRelativeTo(VirtualFile from)

*

Returns: Path relative to VirtualFile gived as a parameter. Note that relative path
is the same whether FILE_TYPE of it is VirtualFileType.DIRECTORY or
VirtualFileType.FILE

public int getPermission()

Shortcut for FILE_PERMISSION property getting.

public Reader getReader()
                  throws java.io.IOException

Returns: Reader which can be used to read file contents.

Throws:

IOException when applied to directory.

public String getShortName()

Shortcut for FILE_SHORT_NAME property getting.

public VirtualFileType getType()

Shortcut for FILE_TYPE property getting.

public VirtualFile getUniqueChild(String prefix, String extension)
                            throws java.io.IOException

Gets unique child named on the base of prefix and extension

Returns: VirtualFile object representing file named prefixNUMBER.extension.

public String getUrl()

Shortcut for FILE_URL property getting.

public VirtualFileManager getVirtualFileManager()

Returns VirtualFileManager instance

public Writer getWriter()
                  throws java.io.IOException

Returns Writer for VirtualFile. It should be closed in order to allow flushing. Opened writer
always works for rewriting file content.

Throws:

IOException when applied to directory.

public boolean hasChild(String name)

Checks if the file has child named name

public boolean isAncestorOf(VirtualFile descendant)

Returns: true if invoking object is ancestor of descendant.

public boolean isCacheDirty()

Returns true if changes were made to cache since file was opened or cache saved/discarded.

public VirtualFile move(VirtualFile newParent, boolean overwrite)
                  throws java.io.IOException

Moves the VirtualFile to another virtual file which must exist and be a directory.

Files can be actually written anew, so no attributes (eg. timestamps) are guarantied to be preserved after moving.

Parameters:

newParent destination directory;

overwrite specifies, if existent file can be overwritten;

Throws:

IOException if VirtualFile cannot be moved.

returns VirtualFile of file in its new location.

public void removeVirtualFileListener(VirtualFileListener listener)

Removes listener

public void saveCache()
                throws java.io.IOException

Save all changes in cache to disk.

public void saveCache(Depth depth)
                throws java.io.IOException

Save all changes in cache to disk.

Parameters:

depth defines, if the command should be recursive.

public void setArrayOfBytes(byte[] array)
                      throws java.io.IOException

Notice: (in current realization) in any case, only value of array would be used in VFS. Unlike
getArrayOfBytes, original instance of array can be modified free without influence VFS cache system.

Throws:

IOException when applied to directory.

public void setShortName(String newName)
                   throws java.io.IOException

Shortcut for FILE_SHORT_NAME property setting.

public void touchContent()

Increases the internal cache age by one, that is file is treated as modified.