| java.lang.Object
 org.apache.lucene.store.Directory
All known Subclasses: org.apache.lucene.store.FSDirectory, org.apache.lucene.store.je.JEDirectory, org.apache.lucene.store.RAMDirectory, org.apache.lucene.store.db.DbDirectory, org.apache.lucene.index.CompoundFileReader,
| Directory | | abstract public class Directory (Code) | | A Directory is a flat list of files. Files may be written once, when they
are created. Once a file is created it may only be opened for read, or
deleted. Random access is permitted both when reading and writing.
Java's i/o APIs not used directly, but rather all i/o is
through this API. This permits things such as:
- implementation of RAM-based indices;
- implementation indices stored in a database, via JDBC;
- implementation of an index as a single file;
Directory locking is implemented by an instance of
LockFactory , and can be changed for each Directory
instance using
Directory.setLockFactory .
author:
Doug Cutting |
| Field Summary | |
| protected LockFactory | lockFactory
Holds the LockFactory instance (implements locking for
this Directory instance). |
| Method Summary | |
| public void | clearLock(String name)
Attempt to clear (forcefully unlock and remove) the
specified lock. | | abstract public void | close()
Closes the store. | | public static void | copy(Directory src, Directory dest, boolean closeDirSrc)
Copy contents of a directory src to a directory dest. | | abstract public IndexOutput | createOutput(String name)
Creates a new, empty file in the directory with the given name.
Returns a stream writing this file. | | abstract public void | deleteFile(String name)
Removes an existing file in the directory. | | abstract public boolean | fileExists(String name)
Returns true iff a file with the given name exists. | | abstract public long | fileLength(String name)
Returns the length of a file in the directory. | | abstract public long | fileModified(String name)
Returns the time the named file was last modified. | | public LockFactory | getLockFactory()
Get the LockFactory that this Directory instance is
using for its locking implementation. | | public String | getLockID()
Return a string identifier that uniquely differentiates
this Directory instance from other Directory instances.
This ID should be the same if two Directory instances
(even in different JVMs and/or on different machines)
are considered "the same index". | | abstract public String[] | list()
Returns an array of strings, one for each file in the
directory. | | public Lock | makeLock(String name)
Construct a
Lock . | | abstract public IndexInput | openInput(String name)
Returns a stream reading an existing file. | | public IndexInput | openInput(String name, int bufferSize)
Returns a stream reading an existing file, with the
specified read buffer size. | | abstract public void | renameFile(String from, String to)
Renames an existing file in the directory. | | public void | setLockFactory(LockFactory lockFactory)
Set the LockFactory that this Directory instance should
use for its locking implementation. | | abstract public void | touchFile(String name)
Set the modified time of an existing file to now. |
| lockFactory | | protected LockFactory lockFactory(Code) | | Holds the LockFactory instance (implements locking for
this Directory instance).
|
| clearLock | | public void clearLock(String name) throws IOException(Code) | | Attempt to clear (forcefully unlock and remove) the
specified lock. Only call this at a time when you are
certain this lock is no longer in use.
Parameters:
name - name of the lock to be cleared. |
| copy | | public static void copy(Directory src, Directory dest, boolean closeDirSrc) throws IOException(Code) | | Copy contents of a directory src to a directory dest.
If a file in src already exists in dest then the
one in dest will be blindly overwritten.
Parameters:
src - source directory
Parameters:
dest - destination directory
Parameters:
closeDirSrc - if true, call Directory.close() method on source directory
throws:
IOException - |
| createOutput | | abstract public IndexOutput createOutput(String name) throws IOException(Code) | | Creates a new, empty file in the directory with the given name.
Returns a stream writing this file.
|
| deleteFile | | abstract public void deleteFile(String name) throws IOException(Code) | | Removes an existing file in the directory.
|
| fileExists | | abstract public boolean fileExists(String name) throws IOException(Code) | | Returns true iff a file with the given name exists.
|
| fileLength | | abstract public long fileLength(String name) throws IOException(Code) | | Returns the length of a file in the directory.
|
| fileModified | | abstract public long fileModified(String name) throws IOException(Code) | | Returns the time the named file was last modified.
|
| getLockFactory | | public LockFactory getLockFactory()(Code) | | Get the LockFactory that this Directory instance is
using for its locking implementation. Note that this
may be null for Directory implementations that provide
their own locking implementation.
|
| getLockID | | public String getLockID()(Code) | | Return a string identifier that uniquely differentiates
this Directory instance from other Directory instances.
This ID should be the same if two Directory instances
(even in different JVMs and/or on different machines)
are considered "the same index". This is how locking
"scopes" to the right index.
|
| list | | abstract public String[] list() throws IOException(Code) | | Returns an array of strings, one for each file in the
directory. This method may return null (for example for
FSDirectory if the underlying directory doesn't
exist in the filesystem or there are permissions
problems).
|
| makeLock | | public Lock makeLock(String name)(Code) | | Construct a
Lock .
Parameters:
name - the name of the lock file |
| renameFile | | abstract public void renameFile(String from, String to) throws IOException(Code) | | Renames an existing file in the directory.
If a file already exists with the new name, then it is replaced.
This replacement is not guaranteed to be atomic.
|
| setLockFactory | | public void setLockFactory(LockFactory lockFactory)(Code) | | Set the LockFactory that this Directory instance should
use for its locking implementation. Each * instance of
LockFactory should only be used for one directory (ie,
do not share a single instance across multiple
Directories).
Parameters:
lockFactory - instance of LockFactory. |
| touchFile | | abstract public void touchFile(String name) throws IOException(Code) | | Set the modified time of an existing file to now.
|
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