Lucene - Analyzer


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Analyzer class is responsible to analyze a document and get the tokens/words from the text which is to be indexed. Without analysis, IndexWriter cannot create index.

Class Declaration

Following is the declaration for org.apache.lucene.analysis.Analyzer class −

public abstract class Analyzer
   extends Object
      implements Closeable

Class Constructors

The following table shows a class constructor −

S.No. Constructor & Description
1

protected Analyzer()

Class Methods

The following table shows the different class methods −

S.No. Method & Description
1

void close()

Frees persistent resources used by this Analyzer.

2

int getOffsetGap(Fieldable field)

Just like getPositionIncrementGap(java.lang.String), except for Token offsets instead.

3

int getPositionIncrementGap(String fieldName)

Invoked before indexing a Fieldable instance if terms have already been added to that field.

4

protected Object getPreviousTokenStream()

Used by Analyzers that implement reusableTokenStream to retrieve previously saved TokenStreams for re-use by the same thread.

5

TokenStream reusableTokenStream(String fieldName, Reader reader)

Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method.

6

protected void setPreviousTokenStream(Object obj)

Used by Analyzers that implement reusableTokenStream to save a TokenStream for later re-use by the same thread.

7

abstract TokenStream tokenStream(String fieldName, Reader reader)

Creates a TokenStream which tokenizes all the text in the provided Reader.

Methods Inherited

This class inherits methods from the following classes −

  • java.lang.Object

lucene_indexing_classes.htm

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