ReversedLinesFileReader (Apache Commons IO 2.5 API)

java.lang.Object
- org.apache.commons.io.input.ReversedLinesFileReader

All Implemented Interfaces:

Closeable, AutoCloseable
```
public class ReversedLinesFileReader
extends Object
implements Closeable
```
Reads lines in a file reversely (similar to a BufferedReader, but starting at the last line). Useful for e.g. searching in log files.

Since:

2.2

Constructor Summary

Constructors
Constructor and Description
`ReversedLinesFileReader(File file)` Deprecated. 2.5 use `ReversedLinesFileReader(File, Charset)` instead
`ReversedLinesFileReader(File file, Charset charset)` Creates a ReversedLinesFileReader with default block size of 4KB and the specified encoding.
`ReversedLinesFileReader(File file, int blockSize, Charset encoding)` Creates a ReversedLinesFileReader with the given block size and encoding.
`ReversedLinesFileReader(File file, int blockSize, String encoding)` Creates a ReversedLinesFileReader with the given block size and encoding.

Method Summary

Methods
Modifier and Type Method and Description

void close()
Closes underlying resources.

String readLine()
Returns the lines of the file from bottom to top.
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods
Modifier and Type	Method and Description
`void`	`close()` Closes underlying resources.
`String`	`readLine()` Returns the lines of the file from bottom to top.

- Constructor Detail
  - ReversedLinesFileReader
```
@Deprecated
public ReversedLinesFileReader(File file)
                        throws IOException
```
    Deprecated. 2.5 use ReversedLinesFileReader(File, Charset) instead
    
    Creates a ReversedLinesFileReader with default block size of 4KB and the platform's default encoding.
    
    Parameters:
    file - the file to be read
    
    Throws:
    
    IOException - if an I/O error occurs
  - ReversedLinesFileReader
```
public ReversedLinesFileReader(File file,
                       Charset charset)
                        throws IOException
```
    Creates a ReversedLinesFileReader with default block size of 4KB and the specified encoding.
    
    Parameters:
    file - the file to be read
    charset - the encoding to use
    
    Throws:
    
    IOException - if an I/O error occurs
    Since:
    
    2.5
  - ReversedLinesFileReader
```
public ReversedLinesFileReader(File file,
                       int blockSize,
                       Charset encoding)
                        throws IOException
```
    Creates a ReversedLinesFileReader with the given block size and encoding.
    
    Parameters:
    file - the file to be read
    blockSize - size of the internal buffer (for ideal performance this should match with the block size of the underlying file system).
    encoding - the encoding of the file
    
    Throws:
    
    IOException - if an I/O error occurs
    Since:
    
    2.3
  - ReversedLinesFileReader
```
public ReversedLinesFileReader(File file,
                       int blockSize,
                       String encoding)
                        throws IOException
```
    Creates a ReversedLinesFileReader with the given block size and encoding.
    
    Parameters:
    file - the file to be read
    blockSize - size of the internal buffer (for ideal performance this should match with the block size of the underlying file system).
    encoding - the encoding of the file
    
    Throws:
    
    IOException - if an I/O error occurs
    
    UnsupportedCharsetException - thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
- Method Detail
  - readLine
```
public String readLine()
                throws IOException
```
    Returns the lines of the file from bottom to top.
    
    Returns:
    the next line or null if the start of the file is reached
    
    Throws:
    
    IOException - if an I/O error occurs
  - close
```
public void close()
           throws IOException
```
    Closes underlying resources.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Throws:
    
    IOException - if an I/O error occurs

Class ReversedLinesFileReader

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ReversedLinesFileReader

ReversedLinesFileReader

ReversedLinesFileReader

ReversedLinesFileReader

Method Detail

readLine

close