DCMIPeriod.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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.opencastproject.metadata.dublincore;

import java.util.Date;

/**
 * A time interval, representing a DCMI period. They may be open.
 * <p>
 * For further information on DCMI periods please refer to <a
 * href="http://dublincore.org/documents/dcmi-period/">http://dublincore.org/documents/dcmi-period/</a>.
 */
public final class DCMIPeriod {

  private final Date start;
  private final Date end;
  private final String name;

  /**
   * Create a new period. To create an open interval you may set one of the boundaries null.
   */
  public DCMIPeriod(Date start, Date end) {
    this(start, end, null);
  }

  /**
   * Create a new period with an optional name. To create an open interval you may set one of the bounbaries null.
   */
  public DCMIPeriod(Date start, Date end, String name) {
    if (start == null && end == null)
      throw new IllegalStateException("A period must be bounded at least at one end");
    if (start != null && end != null && end.before(start))
      throw new IllegalStateException("The end date is before the start date");

    this.start = start;
    this.end = end;
    this.name = name;
  }

  /**
   * Returns the start date of the period or null, if it has only an upper bound.
   */
  public Date getStart() {
    return start;
  }

  /**
   * Returns the end date of the period or null, if it has only a lower bound.
   */
  public Date getEnd() {
    return end;
  }

  /**
   * Returns the optional name of the period.
   *
   * @return the name of the period or null
   */
  public String getName() {
    return name;
  }

  /**
   * Checks if the interval is closed.
   */
  public boolean isClosed() {
    return start != null && end != null;
  }

  /**
   * Checks if the interval has a start boundary.
   */
  public boolean hasStart() {
    return start != null;
  }

  /**
   * Checks if the interval has an end boundary.
   */
  public boolean hasEnd() {
    return end != null;
  }

  /**
   * Checks if the interval has a name.
   */
  public boolean hasName() {
    return name != null;
  }

  @Override
  public String toString() {
    return "DCMIPeriod{" + "start=" + (start != null ? start : "]") + ", end=" + (end != null ? end : "[")
            + (name != null ? ", name='" + name + '\'' : "") + '}';
  }

}