Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.wake.time;
020
021import java.util.Date;
022
023/**
024 * An abstract object that has a timestamp.
025 * That allows us to compare and order objects by the time.
026 */
027public abstract class Time implements Comparable<Time> {
028
029  private final long timestamp;
030
031  /**
032   * Initialize the internal timestamp. Timestamp remains constant
033   * for the entire lifecycle of the object.
034   * @param timestamp timestamp in milliseconds since the beginning
035   * of the epoch (01/01/1970).
036   */
037  public Time(final long timestamp) {
038    this.timestamp = timestamp;
039  }
040
041  /**
042   * Get timestamp in milliseconds since the beginning of the epoch (01/01/1970).
043   * @return Object's timestamp in milliseconds since the start of the epoch.
044   */
045  public final long getTimestamp() {
046    return this.timestamp;
047  }
048
049  /**
050   * Get timestamp in milliseconds since the beginning of the epoch (01/01/1970).
051   * @return Object's timestamp in milliseconds since the start of the epoch.
052   * @deprecated [REEF-1532] Prefer using getTimestamp() instead.
053   * Remove after release 0.16.
054   */
055  public final long getTimeStamp() {
056    return this.timestamp;
057  }
058
059  @Override
060  public String toString() {
061    return this.getClass().getName()
062        + ":[" + this.timestamp + '|' + new Date(this.timestamp) + ']';
063  }
064
065  @Override
066  public int compareTo(final Time other) {
067    final int cmp = Long.compare(this.timestamp, other.timestamp);
068    return cmp != 0 ? cmp : Integer.compare(this.hashCode(), other.hashCode());
069  }
070
071  @Override
072  public boolean equals(final Object other) {
073    return other instanceof Time && compareTo((Time) other) == 0;
074  }
075
076  @Override
077  public int hashCode() {
078    return super.hashCode();
079  }
080}