content: /*
   * 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.calcite.adapter.file;
  
  import org.apache.calcite.adapter.file.JsonEnumerator.JsonDataConverter;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeFactory;
  import org.apache.calcite.schema.Statistic;
  import org.apache.calcite.schema.Statistics;
  import org.apache.calcite.schema.impl.AbstractTable;
  import org.apache.calcite.util.Source;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  
  /**
   * Table based on a JSON file.
   */
  public class JsonTable extends AbstractTable {
    private final Source source;
    private @Nullable RelDataType rowType;
    protected @Nullable List<Object> dataList;
  
    public JsonTable(Source source) {
      this.source = source;
    }
  
    @Override public RelDataType getRowType(RelDataTypeFactory typeFactory) {
      if (rowType == null) {
        rowType = JsonEnumerator.deduceRowType(typeFactory, source).getRelDataType();
      }
      return rowType;
    }
  
    /** Returns the data list of the table. */
    public List<Object> getDataList(RelDataTypeFactory typeFactory) {
      if (dataList == null) {
        JsonDataConverter jsonDataConverter =
            JsonEnumerator.deduceRowType(typeFactory, source);
        dataList = jsonDataConverter.getDataList();
      }
      return dataList;
    }
  
    @Override public Statistic getStatistic() {
      return Statistics.UNKNOWN;
    }
  }
  