java.lang.Object
- org.apache.lucene.store.Directory
- - org.apache.lucene.store.FileSwitchDirectory

All Implemented Interfaces:

Closeable, AutoCloseable
```
public class FileSwitchDirectory
extends Directory
```
Expert: A Directory instance that switches files between two other Directory instances.
Files with the specified extensions are placed in the primary directory; others are placed in the secondary directory. The provided Set must not change once passed to this class, and must allow multiple threads to call contains at once.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary
- Fields inherited from class org.apache.lucene.store.Directory
  isOpen, lockFactory

Constructor Summary

Constructors
Constructor	Description
`FileSwitchDirectory(Set<String> primaryExtensions, Directory primaryDir, Directory secondaryDir, boolean doClose)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the store.
`IndexOutput`	`createOutput(String name)`	Creates a new, empty file in the directory with the given name.
`void`	`deleteFile(String name)`	Removes an existing file in the directory.
`boolean`	`fileExists(String name)`	Returns true iff a file with the given name exists.
`long`	`fileLength(String name)`	Returns the length of a file in the directory.
`long`	`fileModified(String name)`	Returns the time the named file was last modified.
`static String`	`getExtension(String name)`	Utility method to return a file's extension.
`Directory`	`getPrimaryDir()`	Return the primary directory
`Directory`	`getSecondaryDir()`	Return the secondary directory
`String[]`	`listAll()`	Returns an array of strings, one for each file in the directory.
`IndexInput`	`openInput(String name)`	Returns a stream reading an existing file.
`void`	`sync(String name)`	Deprecated.
`void`	`sync(Collection<String> names)`	Ensure that any writes to these files are moved to stable storage.
`void`	`touchFile(String name)`	Deprecated.

Methods inherited from class org.apache.lucene.store.Directory
clearLock, copy, copy, ensureOpen, getLockFactory, getLockID, makeLock, openInput, setLockFactory, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - FileSwitchDirectory
```
public FileSwitchDirectory(Set<String> primaryExtensions,
                           Directory primaryDir,
                           Directory secondaryDir,
                           boolean doClose)
```
- Method Detail
  - getPrimaryDir
```
public Directory getPrimaryDir()
```
    Return the primary directory
  - getSecondaryDir
```
public Directory getSecondaryDir()
```
    Return the secondary directory
  - close
```
public void close()
           throws IOException
```
    Description copied from class: Directory
    
    Closes the store.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in class Directory
    
    Throws:
    
    IOException
  - listAll
```
public String[] listAll()
                 throws IOException
```
    Description copied from class: Directory
    
    Returns an array of strings, one for each file in the directory.
    
    Specified by:
    
    listAll in class Directory
    
    Throws:
    
    NoSuchDirectoryException - if the directory is not prepared for any write operations (such as Directory.createOutput(String)).
    
    IOException - in case of other IO errors
  - getExtension
```
public static String getExtension(String name)
```
    Utility method to return a file's extension.
  - fileExists
```
public boolean fileExists(String name)
                   throws IOException
```
    Description copied from class: Directory
    
    Returns true iff a file with the given name exists.
    
    Specified by:
    
    fileExists in class Directory
    
    Throws:
    
    IOException
  - fileModified
```
public long fileModified(String name)
                  throws IOException
```
    Description copied from class: Directory
    
    Returns the time the named file was last modified.
    
    Specified by:
    
    fileModified in class Directory
    
    Throws:
    
    IOException
  - touchFile
```
@Deprecated
public void touchFile(String name)
               throws IOException
```
    Deprecated.
    
    Description copied from class: Directory
    
    Set the modified time of an existing file to now.
    
    Specified by:
    
    touchFile in class Directory
    
    Throws:
    
    IOException
  - deleteFile
```
public void deleteFile(String name)
                throws IOException
```
    Description copied from class: Directory
    
    Removes an existing file in the directory.
    
    Specified by:
    
    deleteFile in class Directory
    
    Throws:
    
    IOException
  - fileLength
```
public long fileLength(String name)
                throws IOException
```
    Description copied from class: Directory
    Returns the length of a file in the directory. This method follows the following contract:
    
    Throws FileNotFoundException if the file does not exist
    Returns a value ≥0 if the file exists, which specifies its length.
    Specified by:
    
    fileLength in class Directory
    
    Parameters:
    
    name - the name of the file for which to return the length.
    
    Throws:
    
    FileNotFoundException - if the file does not exist.
    
    IOException - if there was an IO error while retrieving the file's length.
  - createOutput
```
public IndexOutput createOutput(String name)
                         throws IOException
```
    Description copied from class: Directory
    
    Creates a new, empty file in the directory with the given name. Returns a stream writing this file.
    
    Specified by:
    
    createOutput in class Directory
    
    Throws:
    
    IOException
  - sync
```
@Deprecated
public void sync(String name)
          throws IOException
```
    Deprecated.
    
    Description copied from class: Directory
    
    Ensure that any writes to this file are moved to stable storage. Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.
    
    Overrides:
    
    sync in class Directory
    
    Throws:
    
    IOException
  - sync
```
public void sync(Collection<String> names)
          throws IOException
```
    Description copied from class: Directory
    
    Ensure that any writes to these files are moved to stable storage. Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.
    
    NOTE: Clients may call this method for same files over and over again, so some impls might optimize for that. For other impls the operation can be a noop, for various reasons.
    
    Overrides:
    
    sync in class Directory
    
    Throws:
    
    IOException
  - openInput
```
public IndexInput openInput(String name)
                     throws IOException
```
    Description copied from class: Directory
    
    Returns a stream reading an existing file.
    
    Specified by:
    
    openInput in class Directory
    
    Throws:
    
    IOException

Class FileSwitchDirectory

Field Summary

Fields inherited from class org.apache.lucene.store.Directory

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.store.Directory

Methods inherited from class java.lang.Object

Constructor Detail

FileSwitchDirectory

Method Detail

getPrimaryDir

getSecondaryDir

close

listAll

getExtension

fileExists

fileModified

touchFile

deleteFile

fileLength

createOutput

sync

sync

openInput