RowComparator.java

/**
 * Licensed 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.
 *
 * Copyright 2012-2016 the original author or authors.
 */
package org.assertj.db.util;

import org.assertj.db.type.Row;
import org.assertj.db.type.Value;

import java.util.Comparator;
import java.util.List;

/**
 * Comparator for the {@code Row}.
 * 
 * @author Régis Pouiller
 * 
 */
public enum RowComparator implements Comparator<Row>{

  /**
   * The singleton
   */
  INSTANCE;

  /**
   * Compare one array of values to another.
   * @param values1 The first array of values.
   * @param values2 The second array of values.
   * @return The result.
   * @see Comparator#compare(Object, Object)
   */
  private static int compare(Value[] values1, Value[] values2) {
    if (values1.length == values2.length) {
      for (int index = 0; index < values1.length; index++) {
        Value value1 = values1[index];
        Value value2 = values2[index];
        Object object1 = value1.getValue();
        Object object2 = value2.getValue();
        if (object1 == null && object2 != null) {
          return 1;
        }
        if (object1 != null && object2 == null) {
          return -1;
        }
        if (object1 instanceof Comparable && object2 instanceof Comparable) {
          @SuppressWarnings("unchecked")
          Comparable<Object> comparable1 = Comparable.class.cast(object1);
          int compare = comparable1.compareTo(object2);
          if (compare != 0) {
            return compare;
          }
        }
      }
    }
    return 0;
  }

  /** {@inheritDoc} */
  @Override
  public int compare(Row row1, Row row2) {
    Value[] pksValues1 = row1.getPksValues();
    Value[] pksValues2 = row2.getPksValues();
    int compare = compare(pksValues1, pksValues2);
    if (compare != 0) {
      return compare;
    }
    List<Value> valuesList1 = row1.getValuesList();
    List<Value> valuesList2 = row2.getValuesList();
    Value[] values1 = valuesList1.toArray(new Value[valuesList1.size()]);
    Value[] values2 = valuesList2.toArray(new Value[valuesList2.size()]);
    return compare(values1, values2);
  }
}