public static void main(String[] args) throws InterruptedException {
   StopWatchTest.test0();
//    StopWatchTest.test1();
}

public static void test0() throws InterruptedException {
   long start = System.currentTimeMillis();
   // do something
   Thread.sleep(100);
  long end = System.currentTimeMillis();
  long start2 = System.currentTimeMillis();
  // do something
  Thread.sleep(200);
  long end2 = System.currentTimeMillis();
  System.out.println("某某1執行耗時:" + (end - start));
  System.out.println("某某2執行耗時:" + (end2 - start2));
}

public static void main(String[] args) throws InterruptedException {
//    StopWatchTest.test0();
   StopWatchTest.test1();
}

public static void test1() throws InterruptedException {
   StopWatch sw = new StopWatch("test");
   sw.start("task1");
   // do something
  Thread.sleep(100);
  sw.stop();
  sw.start("task2");
  // do something
  Thread.sleep(200);
  sw.stop();
  System.out.println("sw.prettyPrint()~~~~~~~~~~~~~~~~~");
  System.out.println(sw.prettyPrint());
}

System.out.println("sw.shortSummary()~~~~~~~~~~~~~~~~~");
System.out.println(sw.shortSummary());
System.out.println("sw.getTotalTimeMillis()~~~~~~~~~~~~~~~~~");
System.out.println(sw.getTotalTimeMillis());

import java.text.NumberFormat;
import java.util.LinkedList;
import java.util.List;

public class StopWatch {
  private final String id;
  private boolean keepTaskList = true;
  private final List<TaskInfo> taskList = new LinkedList();
  private long startTimeMillis;
  private boolean running;
  private String currentTaskName;
  private StopWatch.TaskInfo lastTaskInfo;
  private int taskCount;
  private long totalTimeMillis;

  public StopWatch() {
    this.id = "";
  }

  public StopWatch(String id) {
    this.id = id;
  }

  public void setKeepTaskList(boolean keepTaskList) {
    this.keepTaskList = keepTaskList;
  }

  public void start() throws IllegalStateException {
    this.start("");
  }

  public void start(String taskName) throws IllegalStateException {
    if (this.running) {
      throw new IllegalStateException("Can't start StopWatch: it's already running");
    } else {
      this.startTimeMillis = System.currentTimeMillis();
      this.running = true;
      this.currentTaskName = taskName;
    }
  }

  public void stop() throws IllegalStateException {
    if (!this.running) {
      throw new IllegalStateException("Can't stop StopWatch: it's not running");
    } else {
      long lastTime = System.currentTimeMillis() - this.startTimeMillis;
      this.totalTimeMillis += lastTime;
      this.lastTaskInfo = new StopWatch.TaskInfo(this.currentTaskName, lastTime);
      if (this.keepTaskList) {
        this.taskList.add(this.lastTaskInfo);
      }

      ++this.taskCount;
      this.running = false;
      this.currentTaskName = null;
    }
  }

  public boolean isRunning() {
    return this.running;
  }

  public long getLastTaskTimeMillis() throws IllegalStateException {
    if (this.lastTaskInfo == null) {
      throw new IllegalStateException("No tasks run: can't get last task interval");
    } else {
      return this.lastTaskInfo.getTimeMillis();
    }
  }

  public String getLastTaskName() throws IllegalStateException {
    if (this.lastTaskInfo == null) {
      throw new IllegalStateException("No tasks run: can't get last task name");
    } else {
      return this.lastTaskInfo.getTaskName();
    }
  }

  public StopWatch.TaskInfo getLastTaskInfo() throws IllegalStateException {
    if (this.lastTaskInfo == null) {
      throw new IllegalStateException("No tasks run: can't get last task info");
    } else {
      return this.lastTaskInfo;
    }
  }

  public long getTotalTimeMillis() {
    return this.totalTimeMillis;
  }

  public double getTotalTimeSeconds() {
    return (double) this.totalTimeMillis / 1000.0D;
  }

  public int getTaskCount() {
    return this.taskCount;
  }

  public StopWatch.TaskInfo[] getTaskInfo() {
    if (!this.keepTaskList) {
      throw new UnsupportedOperationException("Task info is not being kept!");
    } else {
      return (StopWatch.TaskInfo[]) this.taskList.toArray(new StopWatch.TaskInfo[this.taskList.size()]);
    }
  }

  public String shortSummary() {
    return "StopWatch '" + this.id + "': running time (millis) = " + this.getTotalTimeMillis();
  }

  public String prettyPrint() {
    StringBuilder sb = new StringBuilder(this.shortSummary());
    sb.append('\n');
    if (!this.keepTaskList) {
      sb.append("No task info kept");
    } else {
      sb.append("-----------------------------------------\n");
      sb.append("ms   %   Task name\n");
      sb.append("-----------------------------------------\n");
      NumberFormat nf = NumberFormat.getNumberInstance();
      nf.setMinimumIntegerDigits(5);
      nf.setGroupingUsed(false);
      NumberFormat pf = NumberFormat.getPercentInstance();
      pf.setMinimumIntegerDigits(3);
      pf.setGroupingUsed(false);
      StopWatch.TaskInfo[] var7;
      int var6 = (var7 = this.getTaskInfo()).length;

      for (int var5 = 0; var5 < var6; ++var5) {
        StopWatch.TaskInfo task = var7[var5];
        sb.append(nf.format(task.getTimeMillis())).append(" ");
        sb.append(pf.format(task.getTimeSeconds() / this.getTotalTimeSeconds())).append(" ");
        sb.append(task.getTaskName()).append("\n");
      }
    }

    return sb.toString();
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder(this.shortSummary());
    if (this.keepTaskList) {
      StopWatch.TaskInfo[] var5;
      int var4 = (var5 = this.getTaskInfo()).length;

      for (int var3 = 0; var3 < var4; ++var3) {
        StopWatch.TaskInfo task = var5[var3];
        sb.append("; [").append(task.getTaskName()).append("] took ").append(task.getTimeMillis());
        long percent = Math.round(100.0D * task.getTimeSeconds() / this.getTotalTimeSeconds());
        sb.append(" = ").append(percent).append("%");
      }
    } else {
      sb.append("; no task info kept");
    }

    return sb.toString();
  }

  public static final class TaskInfo {
    private final String taskName;
    private final long timeMillis;

    TaskInfo(String taskName, long timeMillis) {
      this.taskName = taskName;
      this.timeMillis = timeMillis;
    }

    public String getTaskName() {
      return this.taskName;
    }

    public long getTimeMillis() {
      return this.timeMillis;
    }

    public double getTimeSeconds() {
      return (double) this.timeMillis / 1000.0D;
    }
  }

}