| /* |
| * 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. |
| */ |
| package org.apache.solr.update.processor; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| |
| import org.apache.solr.common.SolrException; |
| import org.apache.solr.core.SolrCore; |
| import org.apache.solr.update.processor.FieldMutatingUpdateProcessor.FieldNameSelector; |
| |
| import static org.apache.solr.common.SolrException.ErrorCode.BAD_REQUEST; |
| import static org.apache.solr.update.processor.FieldMutatingUpdateProcessor.SELECT_NO_FIELDS; |
| |
| /** |
| * An update processor that keeps only the the maximum value from any selected |
| * fields where multiple values are found. Correct behavior requires tha all |
| * of the values in the SolrInputFields being mutated are mutually comparable; |
| * If this is not the case, then a SolrException will br thrown. |
| * <p> |
| * By default, this processor matches no fields. |
| * </p> |
| * |
| * <p> |
| * In the example configuration below, if a document contains multiple integer |
| * values (ie: <code>64, 128, 1024</code>) in the field |
| * <code>largestFileSize</code> then only the biggest value |
| * (ie: <code>1024</code>) will be kept in that field. |
| * <br> |
| * |
| * <pre class="prettyprint"> |
| * <processor class="solr.MaxFieldValueUpdateProcessorFactory"> |
| * <str name="fieldName">largestFileSize</str> |
| * </processor> |
| * </pre> |
| * |
| * @see MinFieldValueUpdateProcessorFactory |
| * @see Collections#max |
| * @since 4.0.0 |
| */ |
| public final class MaxFieldValueUpdateProcessorFactory extends FieldValueSubsetUpdateProcessorFactory { |
| |
| @Override |
| @SuppressWarnings({"unchecked"}) |
| public Collection<Object> pickSubset(@SuppressWarnings({"rawtypes"})Collection values) { |
| @SuppressWarnings({"rawtypes"}) |
| Collection result = values; |
| try { |
| // NOTE: the extra cast to Object is needed to prevent compile |
| // errors on Eclipse Compiler (ecj) used for javadoc lint |
| result = Collections.singletonList((Object) Collections.max(values)); |
| } catch (ClassCastException e) { |
| throw new SolrException |
| (BAD_REQUEST, |
| "Field values are not mutually comparable: " + e.getMessage(), e); |
| } |
| return result; |
| } |
| |
| @Override |
| public FieldNameSelector getDefaultSelector(SolrCore core) { |
| return SELECT_NO_FIELDS; |
| } |
| |
| } |
| |