Java tutorial
/** * 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 * <p> * http://www.apache.org/licenses/LICENSE-2.0 * <p> * 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.metamodel.elasticsearch.elastic1.rest; import java.util.Date; import java.util.List; import java.util.Map; import org.apache.metamodel.data.DataSetHeader; import org.apache.metamodel.data.DefaultRow; import org.apache.metamodel.data.Row; import org.apache.metamodel.elasticsearch.common.ElasticSearchDateConverter; import org.apache.metamodel.query.SelectItem; import org.apache.metamodel.schema.Column; import org.apache.metamodel.schema.ColumnType; import org.apache.metamodel.util.NumberComparator; import com.google.gson.Gson; import com.google.gson.JsonElement; import com.google.gson.JsonObject; /** * Shared/common util functions for the ElasticSearch MetaModel module. */ final class JestElasticSearchUtils { public static Row createRow(JsonObject source, String documentId, DataSetHeader header) { final Object[] values = new Object[header.size()]; for (int i = 0; i < values.length; i++) { final SelectItem selectItem = header.getSelectItem(i); final Column column = selectItem.getColumn(); assert column != null; assert !selectItem.hasFunction(); if (column.isPrimaryKey()) { values[i] = documentId; } else { values[i] = getDataFromColumnType(source.get(column.getName()), column.getType()); } } return new DefaultRow(header, values); } private static Object getDataFromColumnType(JsonElement field, ColumnType type) { if (field == null || field.isJsonNull()) { return null; } if (field.isJsonObject()) { return new Gson().fromJson(field, Map.class); } if (field.isJsonArray()) { return new Gson().fromJson(field, List.class); } if (type.isNumber()) { // Pretty terrible workaround to avoid LazilyParsedNumber // (which is happily output, but not recognized by Jest/GSON). return NumberComparator.toNumber(field.getAsString()); } else if (type.isTimeBased()) { final Date valueToDate = ElasticSearchDateConverter.tryToConvert(field.getAsString()); if (valueToDate == null) { return field.getAsString(); } else { return valueToDate; } } else if (type.isBoolean()) { return field.getAsBoolean(); } else { return field.getAsString(); } } }