Mailing List Archive

otis 02/02/22 12:59:11

Added: src/java/org/apache/lucene/queryParser
MultiFieldQueryParser.java
Log:
- A query parser that searches multiple fields at once.
Initial checkin.
Submitted by: Kelvin Tan
Reviewed by: Otis Gospodnetic

Revision Changes Path
1.1 jakarta-lucene/src/java/org/apache/lucene/queryParser/MultiFieldQueryParser.java

Index: MultiFieldQueryParser.java
===================================================================
package org.apache.lucene.queryParser;

/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
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* must not be used to endorse or promote products
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* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.queryParser.CharStream;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.queryParser.QueryParserTokenManager;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Query;

/**
* A QueryParser which constructs queries to search multiple fields.
*
* @author <a href="mailto:kelvin@relevanz.com">Kelvin Tan</a>
* @version $Revision: 1.1 $
*/
public class MultiFieldQueryParser extends QueryParser
{
public static final int NORMAL_FIELD = 0;
public static final int REQUIRED_FIELD = 1;
public static final int PROHIBITED_FIELD = 2;

public MultiFieldQueryParser(QueryParserTokenManager tm)
{
super(tm);
}

public MultiFieldQueryParser(CharStream stream)
{
super(stream);
}

public MultiFieldQueryParser(String f, Analyzer a)
{
super(f, a);
}

/**
* <p>
* Parses a query which searches on the fields specified.
* <p>
* If x fields are specified, this effectively constructs:
* <pre>
* <code>
* ({field1}:{query}) ({field2}:{query}) ({field3}:{query})...({fieldx}:{query})
* </code>
* </pre>
*
* @param query Query string to parse
* @param fields Fields to search on
* @param analyzer Analyzer to use
* @throws ParserException if query parsing fails
* @throws TokenMgrError if query parsing fails
*/
public static Query parse(String query, String[] fields, Analyzer analyzer)
throws ParseException
{
BooleanQuery bQuery = new BooleanQuery();
for (int i = 0; i < fields.length; i++)
{
Query q = parse(query, fields[i], analyzer);
bQuery.add(q, false, false);
}
return bQuery;
}

/**
* <p>
* Parses a query, searching on the fields specified.
* Use this if you need to specify certain fields as required,
* and others as prohibited.
* <p><pre>
* Usage:
* <code>
* String[] fields = {"filename", "contents", "description"};
* int[] flags = {MultiFieldQueryParser.NORMAL FIELD,
* MultiFieldQueryParser.REQUIRED FIELD,
* MultiFieldQueryParser.PROHIBITED FIELD,};
* parse(query, fields, flags, analyzer);
* </code>
* </pre>
*<p>
* The code above would construct a query:
* <pre>
* <code>
* (filename:{query}) +(contents:{query}) -(description:{query})
* </code>
* </pre>
*
* @param query Query string to parse
* @param fields Fields to search on
* @param flags Flags describing the fields
* @param analyzer Analyzer to use
* @throws ParserException if query parsing fails
* @throws TokenMgrError if query parsing fails
*/
public static Query parse(String query, String[] fields, int[] flags,
Analyzer analyzer)
throws ParseException
{
BooleanQuery bQuery = new BooleanQuery();
for (int i = 0; i < fields.length; i++)
{
Query q = parse(query, fields[i], analyzer);
int flag = flags[i];
switch (flag)
{
case REQUIRED_FIELD:
bQuery.add(q, true, false);
break;
case PROHIBITED_FIELD:
bQuery.add(q, false, true);
break;
default:
bQuery.add(q, false, false);
break;
}
}
return bQuery;
}
}




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