Java tutorial
/* * Copyright 2018 Red Hat, Inc. and/or its affiliates. * * 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.uberfire.ext.metadata.backend.infinispan.ickl; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; import org.apache.lucene.search.BooleanQuery; import org.apache.lucene.search.Query; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.apache.lucene.search.TermQuery; import org.apache.lucene.search.WildcardQuery; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.uberfire.ext.metadata.backend.infinispan.ickl.converters.BooleanQueryConverter; import org.uberfire.ext.metadata.backend.infinispan.ickl.converters.TermQueryConverter; import org.uberfire.ext.metadata.backend.infinispan.ickl.converters.WildcardQueryConverter; public class IckleConverter { private static final String ORDER_BY = "order by "; private static final String WHERE = "where "; private static final String ASC = "ASC"; private static final String DESC = "DESC"; private Logger logger = LoggerFactory.getLogger(IckleConverter.class); private final FieldConverterImpl converterImpl; public IckleConverter() { converterImpl = new FieldConverterImpl(); } public String convert(Query query) { if (TermQuery.class.isAssignableFrom(query.getClass())) { return new TermQueryConverter((TermQuery) query, converterImpl).convert(); } else if (WildcardQuery.class.isAssignableFrom(query.getClass())) { return new WildcardQueryConverter((WildcardQuery) query, converterImpl).convert(); } else if (BooleanQuery.class.isAssignableFrom(query.getClass())) { return new BooleanQueryConverter((BooleanQuery) query, this).convert(); } if (logger.isDebugEnabled()) { logger.debug("Converter not found, MatchAllDocsQuery will be used"); } return ""; } public String convert(Sort sort) { if (sort == null || sort.getSort() == null) { return ""; } List<SortField> fields = Arrays.asList(sort.getSort()); String sortString = fields.stream().filter(sortField -> sortField.getField() != null).map(sortField -> { String key = this.converterImpl.convertKey(sortField.getField()); String sortDirection = ASC; if (sortField.getReverse()) { sortDirection = DESC; } return key + " " + sortDirection; }).collect(Collectors.joining(",")); return sortString; } public String where(Query query) { String queryString = this.convert(query); if (queryString.isEmpty()) { return ""; } else { return WHERE + queryString; } } public String sort(Sort sort) { String sortString = this.convert(sort); if (sortString.isEmpty()) { return ""; } else { return ORDER_BY + sortString; } } }