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* regarding copyright ownership. The ASF licenses this file *
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package org.apache.james.mailbox.lucene.search;
import java.io.Reader;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.cn.smart.SentenceTokenizer;
import org.apache.lucene.analysis.ngram.NGramTokenFilter;
/**
*
* {@link Analyzer} which match substrings. This is needed because of RFC 3501.
*
* From RFC:
*
* In all search keys that use strings, a message matches the key if
* the string is a substring of the field. The matching is
* case-insensitive.
*
*/
public final class StrictImapSearchAnalyzer extends Analyzer {
private final int minTokenLength;
private final int maxTokenLength;
public StrictImapSearchAnalyzer() {
this(3, 40);
}
public StrictImapSearchAnalyzer(int minTokenLength, int maxTokenLength) {
this.minTokenLength = minTokenLength;
this.maxTokenLength = maxTokenLength;
}
/**
* @see org.apache.lucene.analysis.Analyzer#tokenStream(java.lang.String, java.io.Reader)
*/
public TokenStream tokenStream(String fieldName, Reader reader) {
return new NGramTokenFilter(new UpperCaseFilter(new SentenceTokenizer(reader)), minTokenLength, maxTokenLength);
}
}