Java tutorial
/* * Licensed to Elasticsearch under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Elasticsearch 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. */ package org.elasticsearch.search.sort; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Lists; import org.apache.lucene.search.Filter; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.elasticsearch.ElasticsearchIllegalArgumentException; import org.elasticsearch.common.Nullable; import org.elasticsearch.common.xcontent.XContentParser; import org.elasticsearch.index.fielddata.IndexFieldData; import org.elasticsearch.index.fielddata.fieldcomparator.SortMode; import org.elasticsearch.index.mapper.FieldMapper; import org.elasticsearch.index.mapper.ObjectMappers; import org.elasticsearch.index.mapper.core.NumberFieldMapper; import org.elasticsearch.index.mapper.object.ObjectMapper; import org.elasticsearch.index.query.ParsedFilter; import org.elasticsearch.index.search.nested.NestedFieldComparatorSource; import org.elasticsearch.index.search.nested.NonNestedDocsFilter; import org.elasticsearch.search.SearchParseElement; import org.elasticsearch.search.SearchParseException; import org.elasticsearch.search.internal.SearchContext; import java.util.List; /** * */ public class SortParseElement implements SearchParseElement { public static final SortField SORT_SCORE = new SortField(null, SortField.Type.SCORE); private static final SortField SORT_SCORE_REVERSE = new SortField(null, SortField.Type.SCORE, true); private static final SortField SORT_DOC = new SortField(null, SortField.Type.DOC); private static final SortField SORT_DOC_REVERSE = new SortField(null, SortField.Type.DOC, true); public static final String SCORE_FIELD_NAME = "_score"; public static final String DOC_FIELD_NAME = "_doc"; private final ImmutableMap<String, SortParser> parsers; public SortParseElement() { ImmutableMap.Builder<String, SortParser> builder = ImmutableMap.builder(); addParser(builder, new ScriptSortParser()); addParser(builder, new GeoDistanceSortParser()); this.parsers = builder.build(); } private void addParser(ImmutableMap.Builder<String, SortParser> parsers, SortParser parser) { for (String name : parser.names()) { parsers.put(name, parser); } } @Override public void parse(XContentParser parser, SearchContext context) throws Exception { XContentParser.Token token = parser.currentToken(); List<SortField> sortFields = Lists.newArrayListWithCapacity(2); if (token == XContentParser.Token.START_ARRAY) { while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) { if (token == XContentParser.Token.START_OBJECT) { addCompoundSortField(parser, context, sortFields); } else if (token == XContentParser.Token.VALUE_STRING) { addSortField(context, sortFields, parser.text(), false, false, null, null, null, null); } else { throw new ElasticsearchIllegalArgumentException( "malformed sort format, within the sort array, an object, or an actual string are allowed"); } } } else if (token == XContentParser.Token.VALUE_STRING) { addSortField(context, sortFields, parser.text(), false, false, null, null, null, null); } else if (token == XContentParser.Token.START_OBJECT) { addCompoundSortField(parser, context, sortFields); } else { throw new ElasticsearchIllegalArgumentException( "malformed sort format, either start with array, object, or an actual string"); } if (!sortFields.isEmpty()) { // optimize if we just sort on score non reversed, we don't really need sorting boolean sort; if (sortFields.size() > 1) { sort = true; } else { SortField sortField = sortFields.get(0); if (sortField.getType() == SortField.Type.SCORE && !sortField.getReverse()) { sort = false; } else { sort = true; } } if (sort) { context.sort(new Sort(sortFields.toArray(new SortField[sortFields.size()]))); } } } private void addCompoundSortField(XContentParser parser, SearchContext context, List<SortField> sortFields) throws Exception { XContentParser.Token token; while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) { if (token == XContentParser.Token.FIELD_NAME) { String fieldName = parser.currentName(); boolean reverse = false; String missing = null; String innerJsonName = null; boolean ignoreUnmapped = false; SortMode sortMode = null; Filter nestedFilter = null; String nestedPath = null; token = parser.nextToken(); if (token == XContentParser.Token.VALUE_STRING) { String direction = parser.text(); if (direction.equals("asc")) { reverse = SCORE_FIELD_NAME.equals(fieldName); } else if (direction.equals("desc")) { reverse = !SCORE_FIELD_NAME.equals(fieldName); } else { throw new ElasticsearchIllegalArgumentException( "sort direction [" + fieldName + "] not supported"); } addSortField(context, sortFields, fieldName, reverse, ignoreUnmapped, missing, sortMode, nestedPath, nestedFilter); } else { if (parsers.containsKey(fieldName)) { sortFields.add(parsers.get(fieldName).parse(parser, context)); } else { while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) { if (token == XContentParser.Token.FIELD_NAME) { innerJsonName = parser.currentName(); } else if (token.isValue()) { if ("reverse".equals(innerJsonName)) { reverse = parser.booleanValue(); } else if ("order".equals(innerJsonName)) { if ("asc".equals(parser.text())) { reverse = SCORE_FIELD_NAME.equals(fieldName); } else if ("desc".equals(parser.text())) { reverse = !SCORE_FIELD_NAME.equals(fieldName); } } else if ("missing".equals(innerJsonName)) { missing = parser.textOrNull(); } else if ("ignore_unmapped".equals(innerJsonName) || "ignoreUnmapped".equals(innerJsonName)) { ignoreUnmapped = parser.booleanValue(); } else if ("mode".equals(innerJsonName)) { sortMode = SortMode.fromString(parser.text()); } else if ("nested_path".equals(innerJsonName) || "nestedPath".equals(innerJsonName)) { nestedPath = parser.text(); } else { throw new ElasticsearchIllegalArgumentException( "sort option [" + innerJsonName + "] not supported"); } } else if (token == XContentParser.Token.START_OBJECT) { if ("nested_filter".equals(innerJsonName) || "nestedFilter".equals(innerJsonName)) { ParsedFilter parsedFilter = context.queryParserService() .parseInnerFilter(parser); nestedFilter = parsedFilter == null ? null : parsedFilter.filter(); } else { throw new ElasticsearchIllegalArgumentException( "sort option [" + innerJsonName + "] not supported"); } } } addSortField(context, sortFields, fieldName, reverse, ignoreUnmapped, missing, sortMode, nestedPath, nestedFilter); } } } } } private void addSortField(SearchContext context, List<SortField> sortFields, String fieldName, boolean reverse, boolean ignoreUnmapped, @Nullable final String missing, SortMode sortMode, String nestedPath, Filter nestedFilter) { if (SCORE_FIELD_NAME.equals(fieldName)) { if (reverse) { sortFields.add(SORT_SCORE_REVERSE); } else { sortFields.add(SORT_SCORE); } } else if (DOC_FIELD_NAME.equals(fieldName)) { if (reverse) { sortFields.add(SORT_DOC_REVERSE); } else { sortFields.add(SORT_DOC); } } else { FieldMapper fieldMapper = context.smartNameFieldMapper(fieldName); if (fieldMapper == null) { if (ignoreUnmapped) { return; } throw new SearchParseException(context, "No mapping found for [" + fieldName + "] in order to sort on"); } if (!fieldMapper.isSortable()) { throw new SearchParseException(context, "Sorting not supported for field[" + fieldName + "]"); } // Enable when we also know how to detect fields that do tokenize, but only emit one token /*if (fieldMapper instanceof StringFieldMapper) { StringFieldMapper stringFieldMapper = (StringFieldMapper) fieldMapper; if (stringFieldMapper.fieldType().tokenized()) { // Fail early throw new SearchParseException(context, "Can't sort on tokenized string field[" + fieldName + "]"); } }*/ // We only support AVG and SUM on number based fields if (!(fieldMapper instanceof NumberFieldMapper) && (sortMode == SortMode.SUM || sortMode == SortMode.AVG)) { sortMode = null; } if (sortMode == null) { sortMode = resolveDefaultSortMode(reverse); } IndexFieldData.XFieldComparatorSource fieldComparatorSource = context.fieldData() .getForField(fieldMapper).comparatorSource(missing, sortMode); ObjectMapper objectMapper; if (nestedPath != null) { ObjectMappers objectMappers = context.mapperService().objectMapper(nestedPath); if (objectMappers == null) { throw new ElasticsearchIllegalArgumentException( "failed to find nested object mapping for explicit nested path [" + nestedPath + "]"); } objectMapper = objectMappers.mapper(); if (!objectMapper.nested().isNested()) { throw new ElasticsearchIllegalArgumentException( "mapping for explicit nested path is not mapped as nested: [" + nestedPath + "]"); } } else { objectMapper = context.mapperService().resolveClosestNestedObjectMapper(fieldName); } if (objectMapper != null && objectMapper.nested().isNested()) { Filter rootDocumentsFilter = context.filterCache().cache(NonNestedDocsFilter.INSTANCE); Filter innerDocumentsFilter; if (nestedFilter != null) { innerDocumentsFilter = context.filterCache().cache(nestedFilter); } else { innerDocumentsFilter = context.filterCache().cache(objectMapper.nestedTypeFilter()); } fieldComparatorSource = new NestedFieldComparatorSource(sortMode, fieldComparatorSource, rootDocumentsFilter, innerDocumentsFilter); } sortFields.add(new SortField(fieldMapper.names().indexName(), fieldComparatorSource, reverse)); } } private static SortMode resolveDefaultSortMode(boolean reverse) { return reverse ? SortMode.MAX : SortMode.MIN; } }