org.apache.lucene.queryParser.standard
Class QueryParserUtil

java.lang.Object
  org.apache.lucene.queryParser.standard.QueryParserUtil

public final class QueryParserUtil
extends Object

This class defines utility methods to (help) parse query strings into Query objects.

Constructor Summary

QueryParserUtil()

Method Summary

static String	escape(String s) Returns a String where those characters that TextParser expects to be escaped are escaped by a preceding \.
static Query	parse(String[] queries, String[] fields, Analyzer analyzer) Parses a query which searches on the fields specified.
static Query	parse(String[] queries, String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer) Parses a query, searching on the fields specified.
static Query	parse(String query, String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer) Parses a query, searching on the fields specified.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryParserUtil

public QueryParserUtil()

Method Detail

parse

public static Query parse(String[] queries,
                          String[] fields,
                          Analyzer analyzer)
                   throws QueryNodeException

Parses a query which searches on the fields specified.

If x fields are specified, this effectively constructs:

 <code>
 (field1:query1) (field2:query2) (field3:query3)...(fieldx:queryx)
 </code>
 

Parameters:

queries - Queries strings to parse

fields - Fields to search on

analyzer - Analyzer to use

Throws:

IllegalArgumentException - if the length of the queries array differs from the length of the fields array

QueryNodeException

parse

public static Query parse(String query,
                          String[] fields,
                          BooleanClause.Occur[] flags,
                          Analyzer analyzer)
                   throws QueryNodeException

Parses a query, searching on the fields specified. Use this if you need to specify certain fields as required, and others as prohibited.

 Usage:
 <code>
 String[] fields = {"filename", "contents", "description"};
 BooleanClause.Occur[] flags = {BooleanClause.Occur.SHOULD,
                BooleanClause.Occur.MUST,
                BooleanClause.Occur.MUST_NOT};
 MultiFieldQueryParser.parse("query", fields, flags, analyzer);
 </code>
 

The code above would construct a query:

 <code>
 (filename:query) +(contents:query) -(description:query)
 </code>
 

Parameters:

query - Query string to parse

fields - Fields to search on

flags - Flags describing the fields

analyzer - Analyzer to use

Throws:

IllegalArgumentException - if the length of the fields array differs from the length of the flags array

QueryNodeException

parse

public static Query parse(String[] queries,
                          String[] fields,
                          BooleanClause.Occur[] flags,
                          Analyzer analyzer)
                   throws QueryNodeException

Parses a query, searching on the fields specified. Use this if you need to specify certain fields as required, and others as prohibited.

 Usage:
 <code>
 String[] query = {"query1", "query2", "query3"};
 String[] fields = {"filename", "contents", "description"};
 BooleanClause.Occur[] flags = {BooleanClause.Occur.SHOULD,
                BooleanClause.Occur.MUST,
                BooleanClause.Occur.MUST_NOT};
 MultiFieldQueryParser.parse(query, fields, flags, analyzer);
 </code>
 

The code above would construct a query:

 <code>
 (filename:query1) +(contents:query2) -(description:query3)
 </code>
 

Parameters:

queries - Queries string to parse

fields - Fields to search on

flags - Flags describing the fields

analyzer - Analyzer to use

Throws:

IllegalArgumentException - if the length of the queries, fields, and flags array differ

QueryNodeException

escape

public static String escape(String s)

Returns a String where those characters that TextParser expects to be escaped are escaped by a preceding \.