org.apache.lucene.analysis

Class CharFilter

java.lang.Object

java.io.Reader

org.apache.lucene.analysis.CharFilter

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

Direct Known Subclasses:

BaseCharFilter, PersianCharFilter

public abstract class CharFilter
extends Reader

Subclasses of CharFilter can be chained to filter a Reader They can be used as Reader with additional offset correction. Tokenizers will automatically use correctOffset(int) if a CharFilter subclass is used.

This class is abstract: at a minimum you must implement Reader.read(char[], int, int), transforming the input in some way from input, and correct(int) to adjust the offsets to match the originals.

You can optionally provide more efficient implementations of additional methods like Reader.read(), Reader.read(char[]), Reader.read(java.nio.CharBuffer), but this is not required.

For examples and integration with Analyzer, see the Analysis package documentation.

Constructor Summary

Constructors

Constructor and Description
CharFilter(Reader input) Create a new CharFilter wrapping the provided reader.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying input stream.
int	correctOffset(int currentOff) Chains the corrected offset through the input CharFilter(s).

Methods inherited from class java.io.Reader

mark, markSupported, read, read, read, read, ready, reset, skip

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CharFilter

public CharFilter(Reader input)

Create a new CharFilter wrapping the provided reader.

Parameters:

input - a Reader, can also be a CharFilter for chaining.

Method Detail

close

public void close()
           throws IOException

Closes the underlying input stream.

NOTE: The default implementation closes the input Reader, so be sure to call super.close() when overriding this method.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader

Throws:

IOException

correctOffset

public final int correctOffset(int currentOff)

Chains the corrected offset through the input CharFilter(s).