exec/java-exec/src/main/java/org/apache/drill/exec/store/easy/json/parser/FullValueParser.java

/*
 * 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.drill.exec.store.easy.json.parser;

import com.fasterxml.jackson.core.JsonToken;

public abstract class FullValueParser extends AbstractElementParser {

  private ObjectParser objectParser;
  private ArrayParser arrayParser;

  public FullValueParser(JsonStructureParser structParser) {
    super(structParser);
  }

  /**
   * Parses <code>true | false | null | integer | float | string|
   *              embedded-object | { ... } | [ ... ]</code>
   */
  @Override
  public void parse(TokenIterator tokenizer) {
    JsonToken token = tokenizer.requireNext();
    switch (token) {
    case START_OBJECT:
      // Position: { ^
      if (objectParser == null) {
        // No object parser yet. May be that the value was null,
        // or may be that it changed types.
        objectParser = buildObjectParser(tokenizer);
      }
      objectParser.parse(tokenizer);
      break;

    case START_ARRAY:
      // Position: [ ^
      if (arrayParser == null) {
        // No array parser yet. May be that the value was null,
        // or may be that it changed types.
        arrayParser = buildArrayParser(tokenizer);
      }
      arrayParser.parse(tokenizer);
      break;

    default:
      onValue(token, tokenizer);
    }
  }

  protected abstract void onValue(JsonToken token, TokenIterator tokenizer);
  protected abstract ObjectParser buildObjectParser(TokenIterator tokenizer);
  protected abstract ArrayParser buildArrayParser(TokenIterator tokenizer);
}