| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.hadoop.mapreduce; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.io.WritableComparable; |
| |
| /** |
| * A general identifier, which internally stores the id |
| * as an integer. This is the super class of {@link JobID}, |
| * {@link TaskID} and {@link TaskAttemptID}. |
| * |
| * @see JobID |
| * @see TaskID |
| * @see TaskAttemptID |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public abstract class ID implements WritableComparable<ID> { |
| protected static final char SEPARATOR = '_'; |
| protected int id; |
| |
| /** constructs an ID object from the given int */ |
| public ID(int id) { |
| this.id = id; |
| } |
| |
| protected ID() { |
| } |
| |
| /** returns the int which represents the identifier */ |
| public int getId() { |
| return id; |
| } |
| |
| @Override |
| public String toString() { |
| return String.valueOf(id); |
| } |
| |
| @Override |
| public int hashCode() { |
| return id; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) |
| return true; |
| if(o == null) |
| return false; |
| if (o.getClass() == this.getClass()) { |
| ID that = (ID) o; |
| return this.id == that.id; |
| } |
| else |
| return false; |
| } |
| |
| /** Compare IDs by associated numbers */ |
| public int compareTo(ID that) { |
| return this.id - that.id; |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| this.id = in.readInt(); |
| } |
| |
| public void write(DataOutput out) throws IOException { |
| out.writeInt(id); |
| } |
| |
| } |