/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springmodules.lucene.search.core;
import java.io.IOException;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.Searcher;
/**
* Generic callback interface for code that operates on a Lucene Searcher.
* Allows to execute any number of operations on a single Searcher.
*
* <p>This is particularly useful for delegating to existing data access code
* that expects an Searcher to work on and throws IOException. For newly
* written code, it is strongly recommended to use LuceneSearchTemplate's more
* specific methods.
*
* @author Brian McCallister
* @author Thierry Templier
* @see org.springmodules.lucene.search.core.LuceneSearchTemplate
*/
public interface SearcherCallback {
/**
* Gets called by <code>LuceneSearchTemplate.search</code> with an active Lucene
* Searcher. Does not need to care about activating or closing the Searcher.
*
* <p>Allows for returning a result object created within the callback, i.e.
* a domain object or a collection of domain objects. A thrown
* RuntimeException is treated as application exception: it gets propagated
* to the caller of the template.
*
* @param searcher an active Searcher
* @return a result object, or null if none
* @throws IOException if thrown by a Lucene method, to be auto-converted
* to a LuceneSearchException
*/
public Object doWithSearcher(Searcher searcher) throws IOException,ParseException;
}