## org.apache.lucene.analysis
Class CharFilter

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

All Implemented Interfaces:
  Closeable, Readable

Direct Known Subclasses:
  BaseCharFilter

    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. `Tokenizer`s will automatically use `correctOffset(int)` if a CharFilter/CharStream subclass is used.

Field Summary
`protected CharStream` `input`

Fields inherited from class java.io.Reader
`lock`

Constructor Summary
`protected` `CharFilter(CharStream in)`

Method Summary
`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
`read, read, read, ready, skip`

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 `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`