## org.apache.lucene.analysis
Class CharStream

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

All Implemented Interfaces:
  Closeable, Readable

Direct Known Subclasses:
  CharFilter, CharReader

    public abstract class CharStream

extends Reader

CharStream adds `correctOffset(int)` functionality over `Reader`. All Tokenizers accept a CharStream instead of `Reader` as input, which enables arbitrary character based filtering before tokenization. The `correctOffset(int)` method fixed offsets to account for removal or insertion of characters, so that the offsets reported in the tokens match the character offsets of the original Reader.

Field Summary

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

Constructor Summary
`CharStream()`

Method Summary
`abstract int` `correctOffset(int currentOff)` Called by CharFilter(s) and Tokenizer to correct token offset.

Methods inherited from class java.io.Reader
`close, mark, markSupported, read, read, read, read, ready, reset, skip`

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

Constructor Detail

### CharStream

    public CharStream()

Method Detail

### correctOffset

    public abstract int correctOffset(int currentOff)

  Called by CharFilter(s) and Tokenizer to correct token offset.

  Parameters:
    `currentOff` - offset as seen in the output
  Returns:
    corrected offset based on the input