package org.apache.solr.highlight;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.lucene.search.Query;
import org.apache.solr.common.params.HighlightParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrConfig;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.search.DocList;
import org.apache.solr.util.SolrPluginUtils;
public abstract class SolrHighlighter
{
public static Logger log = LoggerFactory.getLogger(SolrHighlighter.class);
// Thread safe registry
protected final Map<String,SolrFormatter> formatters =
new HashMap<String, SolrFormatter>();
// Thread safe registry
protected final Map<String,SolrEncoder> encoders =
new HashMap<String, SolrEncoder>();
// Thread safe registry
protected final Map<String,SolrFragmenter> fragmenters =
new HashMap<String, SolrFragmenter>() ;
// Thread safe registry
protected final Map<String, SolrFragListBuilder> fragListBuilders =
new HashMap<String, SolrFragListBuilder>() ;
// Thread safe registry
protected final Map<String, SolrFragmentsBuilder> fragmentsBuilders =
new HashMap<String, SolrFragmentsBuilder>() ;
// Thread safe registry
protected final Map<String, SolrBoundaryScanner> boundaryScanners =
new HashMap<String, SolrBoundaryScanner>() ;
@Deprecated
public abstract void initalize( SolrConfig config );
/**
* Check whether Highlighting is enabled for this request.
* @param params The params controlling Highlighting
* @return <code>true</code> if highlighting enabled, <code>false</code> if not.
*/
public boolean isHighlightingEnabled(SolrParams params) {
return params.getBool(HighlightParams.HIGHLIGHT, false);
}
/**
* Return a String array of the fields to be highlighted.
* Falls back to the programatic defaults, or the default search field if the list of fields
* is not specified in either the handler configuration or the request.
* @param query The current Query
* @param request The current SolrQueryRequest
* @param defaultFields Programmatic default highlight fields, used if nothing is specified in the handler config or the request.
*/
public String[] getHighlightFields(Query query, SolrQueryRequest request, String[] defaultFields) {
String fields[] = request.getParams().getParams(HighlightParams.FIELDS);
// if no fields specified in the request, or the handler, fall back to programmatic default, or default search field.
if(emptyArray(fields)) {
// use default search field if highlight fieldlist not specified.
if (emptyArray(defaultFields)) {
String defaultSearchField = request.getSchema().getDefaultSearchFieldName();
fields = null == defaultSearchField ? new String[]{} : new String[]{defaultSearchField};
}
else {
fields = defaultFields;
}
}
else if (fields.length == 1) {
if (fields[0].contains("*")) {
// create a Java regular expression from the wildcard string
String fieldRegex = fields[0].replaceAll("\\*", ".*");
Collection<String> storedHighlightFieldNames = request.getSearcher().getStoredHighlightFieldNames();
List<String> storedFieldsToHighlight = new ArrayList<String>();
for (String storedFieldName: storedHighlightFieldNames) {
if (storedFieldName.matches(fieldRegex)) {
storedFieldsToHighlight.add(storedFieldName);
}
}
fields = storedFieldsToHighlight.toArray(new String[] {});
} else {
// if there's a single request/handler value, it may be a space/comma separated list
fields = SolrPluginUtils.split(fields[0]);
}
}
return fields;
}
protected boolean emptyArray(String[] arr) {
return (arr == null || arr.length == 0 || arr[0] == null || arr[0].trim().length() == 0);
}
/**
* Generates a list of Highlighted query fragments for each item in a list
* of documents, or returns null if highlighting is disabled.
*
* @param docs query results
* @param query the query
* @param req the current request
* @param defaultFields default list of fields to summarize
*
* @return NamedList containing a NamedList for each document, which in
* turns contains sets (field, summary) pairs.
*/
@SuppressWarnings("unchecked")
public abstract NamedList<Object> doHighlighting(DocList docs, Query query, SolrQueryRequest req, String[] defaultFields) throws IOException;
}