Java tutorial
/** * 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 java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.Writable; import org.apache.hadoop.io.WritableUtils; import org.apache.hadoop.mapred.TIPStatus; import org.apache.hadoop.mapred.TaskID; import org.apache.hadoop.util.StringInterner; /** A report on the state of a task. */ @InterfaceAudience.Private @InterfaceStability.Evolving public class TaskReport implements Writable { private TaskID taskid; private float progress; private String state; private String[] diagnostics; private long startTime; private long finishTime; private Counters counters; private TIPStatus currentStatus; private Collection<TaskAttemptID> runningAttempts = new ArrayList<TaskAttemptID>(); private TaskAttemptID successfulAttempt = new TaskAttemptID(); public TaskReport() { taskid = new TaskID(); } /** * Creates a new TaskReport object * @param taskid * @param progress * @param state * @param diagnostics * @param currentStatus * @param startTime * @param finishTime * @param counters */ public TaskReport(TaskID taskid, float progress, String state, String[] diagnostics, TIPStatus currentStatus, long startTime, long finishTime, Counters counters) { this.taskid = taskid; this.progress = progress; this.state = state; this.diagnostics = diagnostics; this.currentStatus = currentStatus; this.startTime = startTime; this.finishTime = finishTime; this.counters = counters; } /** The string of the task ID. */ public String getTaskId() { return taskid.toString(); } /** The ID of the task. */ public TaskID getTaskID() { return taskid; } /** The amount completed, between zero and one. */ public float getProgress() { return progress; } /** The most recent state, reported by the Reporter. */ public String getState() { return state; } /** A list of error messages. */ public String[] getDiagnostics() { return diagnostics; } /** A table of counters. */ public Counters getTaskCounters() { return counters; } /** The current status */ public TIPStatus getCurrentStatus() { return currentStatus; } /** * Get finish time of task. * @return 0, if finish time was not set else returns finish time. */ public long getFinishTime() { return finishTime; } /** * set finish time of task. * @param finishTime finish time of task. */ protected void setFinishTime(long finishTime) { this.finishTime = finishTime; } /** * Get start time of task. * @return 0 if start time was not set, else start time. */ public long getStartTime() { return startTime; } /** * set start time of the task. */ protected void setStartTime(long startTime) { this.startTime = startTime; } /** * set successful attempt ID of the task. */ protected void setSuccessfulAttemptId(TaskAttemptID t) { successfulAttempt = t; } /** * Get the attempt ID that took this task to completion */ public TaskAttemptID getSuccessfulTaskAttemptId() { return successfulAttempt; } /** * set running attempt(s) of the task. */ protected void setRunningTaskAttemptIds(Collection<TaskAttemptID> runningAttempts) { this.runningAttempts = runningAttempts; } /** * Get the running task attempt IDs for this task */ public Collection<TaskAttemptID> getRunningTaskAttemptIds() { return runningAttempts; } @Override public boolean equals(Object o) { if (o == null) return false; if (o.getClass().equals(this.getClass())) { TaskReport report = (TaskReport) o; return counters.equals(report.getTaskCounters()) && Arrays.toString(this.diagnostics).equals(Arrays.toString(report.getDiagnostics())) && this.finishTime == report.getFinishTime() && this.progress == report.getProgress() && this.startTime == report.getStartTime() && this.state.equals(report.getState()) && this.taskid.equals(report.getTaskID()); } return false; } @Override public int hashCode() { return (counters.toString() + Arrays.toString(this.diagnostics) + this.finishTime + this.progress + this.startTime + this.state + this.taskid.toString()).hashCode(); } ////////////////////////////////////////////// // Writable ////////////////////////////////////////////// public void write(DataOutput out) throws IOException { taskid.write(out); out.writeFloat(progress); Text.writeString(out, state); out.writeLong(startTime); out.writeLong(finishTime); WritableUtils.writeStringArray(out, diagnostics); counters.write(out); WritableUtils.writeEnum(out, currentStatus); if (currentStatus == TIPStatus.RUNNING) { WritableUtils.writeVInt(out, runningAttempts.size()); TaskAttemptID t[] = new TaskAttemptID[0]; t = runningAttempts.toArray(t); for (int i = 0; i < t.length; i++) { t[i].write(out); } } else if (currentStatus == TIPStatus.COMPLETE) { successfulAttempt.write(out); } } public void readFields(DataInput in) throws IOException { this.taskid.readFields(in); this.progress = in.readFloat(); this.state = StringInterner.weakIntern(Text.readString(in)); this.startTime = in.readLong(); this.finishTime = in.readLong(); diagnostics = WritableUtils.readStringArray(in); counters = new Counters(); counters.readFields(in); currentStatus = WritableUtils.readEnum(in, TIPStatus.class); if (currentStatus == TIPStatus.RUNNING) { int num = WritableUtils.readVInt(in); for (int i = 0; i < num; i++) { TaskAttemptID t = new TaskAttemptID(); t.readFields(in); runningAttempts.add(t); } } else if (currentStatus == TIPStatus.COMPLETE) { successfulAttempt.readFields(in); } } }