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'rapiddweller Common' is an open source Java library forked from Databene Commons by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

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/*
 * Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
 * All rights reserved.
 *
 * 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.
 */

package com.rapiddweller.common.comparator;

import java.util.Comparator;

/**
 * Delegates comparation to a chain of comparators.
 * They are evaluated consecutively and the first result that is not zero is returned.
 * If all used Comparators return zero, zero is returned as the comparation result.
 * You can use this, e.g. for ordering objects by attributes of different priority,
 * e.g. country, city.
 * Created: 22.05.2007 18:16:15
 *
 * @param  the type of objects to be compared
 * @author Volker Bergmann
 */
public class ComparatorChain implements Comparator {

  private final Comparator[] comparators;

  /**
   * Instantiates a new Comparator chain.
   *
   * @param comparators the comparators
   */
  @SafeVarargs
  public ComparatorChain(Comparator... comparators) {
    this.comparators = comparators;
  }

  @Override
  public int compare(E e1, E e2) {
    for (Comparator comparator : comparators) {
      int diff = comparator.compare(e1, e2);
      if (diff != 0) {
        return diff;
      }
    }
    return 0;
  }
}