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'jdbacl' stands for 'Java DataBase ACcess Layer' and provides utilities for accessing JDBC databases from Java programs, retrieving meta information in an object model and querying database data. 'rapiddweller jdbacl' is forked from Databene jdbacl by Volker Bergmann.

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/*
 * (c) Copyright 2010-2011 by Volker Bergmann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted under the terms of the
 * GNU General Public License (GPL).
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package com.rapiddweller.jdbacl.identity.mem;

import com.rapiddweller.common.HeavyweightIterator;
import com.rapiddweller.common.bean.ObjectOrArray;
import com.rapiddweller.common.exception.ExceptionFactory;
import com.rapiddweller.jdbacl.identity.IdentityModel;
import com.rapiddweller.jdbacl.identity.KeyMapper;
import com.rapiddweller.jdbacl.model.Database;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;

import java.io.IOException;
import java.sql.Connection;
import java.util.HashMap;
import java.util.Map;

/**
 * Parent for classes that map the primary key values of the rows of one table in one database
 * to their natural keys.


 * Created: 07.09.2010 14:11:16
 * @author Volker Bergmann
 * @since 0.6.4
 */
public abstract class AbstractTableMapper {

  private static final Logger logger = LoggerFactory.getLogger(AbstractTableMapper.class);

  protected final KeyMapper root;
  protected final Connection connection;
  protected final String dbId;
  protected final IdentityModel identity;
  private final Map pkToNk;
  private MapperState state;
  final Database database;

  protected AbstractTableMapper(KeyMapper root, Connection connection, String dbId, IdentityModel identity, Database database) {
    this.root = root;
    this.connection = connection;
    this.dbId = dbId;
    this.identity = identity;
    this.database = database;
    this.pkToNk = new HashMap<>(1000);
    this.state = MapperState.CREATED;
  }

  // interface -------------------------------------------------------------------------------------------------------

  public void store(Object pk, String naturalKey) {
    if (state == MapperState.CREATED) {
      state = MapperState.PASSIVE;
    }
    ObjectOrArray globalRowId = new ObjectOrArray(pk);
    pkToNk.put(globalRowId, naturalKey);
  }

  public String getNaturalKey(Object pk) {
    assureInitialized();
    return pkToNk.get(new ObjectOrArray(pk));
  }

  // helpers ---------------------------------------------------------------------------------------------------------

  private void populate() {
    this.state = MapperState.POPULATING;
    logger.debug("Populating key mapper for table {} on database {}", identity.getTableName(), dbId);
    try (HeavyweightIterator iterator = identity.createNkPkIterator(connection, dbId, root, database)) {
      while (iterator.hasNext()) {
        Object[] nkPkTuple = iterator.next();
        Object pk = identity.extractPK(nkPkTuple);
        String nk = identity.extractNK(nkPkTuple);
        store(pk, nk);
      }
      this.state = MapperState.POPULATED;
    } catch (IOException e) {
      throw ExceptionFactory.getInstance().operationFailed("table population failed", e);
    }
  }

  protected void assureInitialized() {
    if (state == MapperState.CREATED) {
      populate();
    }
  }

}