JournalFile (Oak Segment Tar 1.22.13 API)

All Known Implementing Classes:

LocalJournalFile, SplitJournalFile
```
public interface JournalFile
```
The journal is a special, atomically updated file that records the state of the repository as a sequence of references to successive root node records. See oak-segment-tar documentation for more details.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`exists()`	Check if the journal already exists.
`String`	`getName()`	Return the name representing the journal file.
`JournalFileReader`	`openJournalReader()`	Opens the journal file for reading.
`JournalFileWriter`	`openJournalWriter()`	Opens the journal file for writing.

- Method Detail
  - openJournalReader
```
JournalFileReader openJournalReader()
                             throws IOException
```
    Opens the journal file for reading. The returned object will represent the current state of the journal. Subsequent writes made by the JournalFileWriter won't be visible until a new JournalFileReader is opened.
    
    Returns:
    
    the reader representing the current state of the journal
    
    Throws:
    
    IOException
  - openJournalWriter
```
JournalFileWriter openJournalWriter()
                             throws IOException
```
    Opens the journal file for writing.
    
    Returns:
    
    Throws:
    
    IOException
  - getName
```
String getName()
```
    Return the name representing the journal file.
    
    Returns:
    
    name (eg. file name) representing the journal
  - exists
```
boolean exists()
```
    Check if the journal already exists.
    
    Returns:
    
    true if the journal has been already created by the JournalFileWriter