java.lang.Object
- java.io.Reader
- - org.apache.lucene.analysis.CharStream
  - - org.apache.lucene.analysis.CharFilter

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

Direct Known Subclasses:

BaseCharFilter, PersianCharFilter
```
public abstract class CharFilter
extends CharStream
```
Subclasses of CharFilter can be chained to filter CharStream. They can be used as Reader with additional offset correction. Tokenizers will automatically use correctOffset(int) if a CharFilter/CharStream subclass is used.

Field Summary

Fields
Modifier and Type Field Description

protected CharStream input
- Fields inherited from class java.io.Reader
  lock

Constructor Summary

Constructors
Modifier Constructor Description

protected CharFilter(CharStream in)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`
`protected int`	`correct(int currentOff)`	Subclass may want to override to correct the current offset.
`int`	`correctOffset(int currentOff)`	Chains the corrected offset through the input CharFilter.
`void`	`mark(int readAheadLimit)`
`boolean`	`markSupported()`
`int`	`read(char[] cbuf, int off, int len)`
`void`	`reset()`

Methods inherited from class java.io.Reader
nullReader, read, read, read, ready, skip, transferTo

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

- Field Detail
  - input
```
protected CharStream input
```
- Constructor Detail
  - CharFilter
```
protected CharFilter(CharStream in)
```
- Method Detail
  - correct
```
protected int correct(int currentOff)
```
    Subclass may want to override to correct the current offset.
    
    Parameters:
    
    currentOff - current offset
    
    Returns:
    
    corrected offset
  - correctOffset
```
public final int correctOffset(int currentOff)
```
    Chains the corrected offset through the input CharFilter.
    
    Specified by:
    
    correctOffset in class CharStream
    
    Parameters:
    
    currentOff - offset as seen in the output
    
    Returns:
    
    corrected offset based on the input
  - close
```
public void close()
           throws IOException
```
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in class Reader
    
    Throws:
    
    IOException
  - read
```
public int read(char[] cbuf,
                int off,
                int len)
         throws IOException
```
    Specified by:
    
    read in class Reader
    
    Throws:
    
    IOException
  - markSupported
```
public boolean markSupported()
```
    Overrides:
    
    markSupported in class Reader
  - mark
```
public void mark(int readAheadLimit)
          throws IOException
```
    Overrides:
    
    mark in class Reader
    
    Throws:
    
    IOException
  - reset
```
public void reset()
           throws IOException
```
    Overrides:
    
    reset in class Reader
    
    Throws:
    
    IOException

Class CharFilter

Field Summary

Fields inherited from class java.io.Reader

Constructor Summary

Method Summary

Methods inherited from class java.io.Reader

Methods inherited from class java.lang.Object

Field Detail

input

Constructor Detail

CharFilter

Method Detail

correct

correctOffset

close

read

markSupported

mark

reset