StopWatch (Commons Time

java.lang.Object
- de.weltraumschaf.commons.time.StopWatch

```
public final class StopWatch
extends Object
```
StopWatch provides a convenient API for timings.
To start the watch, call start(). At this point you can:
- split() the watch to get the time whilst the watch continues in the background. unsplit() will remove the effect of the split. At this point, these three options are available again.
- suspend() the watch to pause it. resume() allows the watch to continue. Any time between the suspend and resume will not be counted in the total. At this point, these three options are available again.
- stop() the watch to complete the timing session.
It is intended that the output methods toString() and getTime() should only be called after stop, split or suspend, however a suitable result will be returned at other points.

NOTE: As from v2.1, the methods protect against inappropriate calls. Thus you cannot now call stop before start, resume before suspend or unsplit before split.
1. split(), suspend(), or stop() cannot be invoked twice
2. unsplit() may only be called if the watch has been split()
3. resume() may only be called if the watch has been suspend()
4. start() cannot be called twice without calling reset()
This class is not thread-safe
Since:

1.0.0

Author:

Sven Strittmatter <weltraumschaf@googlemail.com>

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`StopWatch.SplitState` Enumeration type which indicates the split status of stopwatch.
`(package private) static class`	`StopWatch.State` Enumeration type which indicates the status of stopwatch.

Field Summary

Fields
Modifier and Type	Field and Description
`private static String`	`DATE_FORMAT` Default format for string representation.
`private static long`	`NANO_2_MILLIS` Factor to convert from nanoseconds to milliseconds.
`(package private) StopWatch.State`	`runningState` The current running state of the StopWatch.
`(package private) StopWatch.SplitState`	`splitState` Whether the stopwatch has a split time recorded.
`private long`	`startTime` The start time.
`private long`	`startTimeMillis` The start time in Millis - nanoTime is only for elapsed time so we need to also store the currentTimeMillis to maintain the old getStartTime API.
`private long`	`stopTime` The stop time.

Constructor Summary

Constructors
Constructor and Description

StopWatch()

Constructors
Constructor and Description
`StopWatch()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`long`	`getNanoTime()` Get the time on the stopwatch in nanoseconds.
`long`	`getSplitNanoTime()` Get the split time on the stopwatch in nanoseconds.
`long`	`getSplitTime()` Get the split time on the stopwatch.
`long`	`getStartTime()` Returns the time this stopwatch was started.
`long`	`getTime()` Get the time on the stopwatch.
`boolean`	`isStarted()` The method is used to find out if the StopWatch is started.
`boolean`	`isStopped()` This method is used to find out whether the StopWatch is stopped.
`boolean`	`isSuspended()` This method is used to find out whether the StopWatch is suspended.
`void`	`reset()` Resets the stopwatch.
`void`	`resume()` Resume the stopwatch after a suspend.
`void`	`split()` Split the time.
`void`	`start()` Start the stopwatch.
`void`	`stop()` Stop the stopwatch.
`void`	`suspend()` Suspend the stopwatch for later resumption.
`String`	`toSplitString()` Gets a summary of the split time that the stopwatch recorded as a string.
`String`	`toString()` Gets a summary of the time that the stopwatch recorded as a string.
`void`	`unsplit()` Remove a split.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DATE_FORMAT
```
private static final String DATE_FORMAT
```
    Default format for string representation.
    
    See Also:
    
    Constant Field Values
  - NANO_2_MILLIS
```
private static final long NANO_2_MILLIS
```
    Factor to convert from nanoseconds to milliseconds.
    
    See Also:
    
    Constant Field Values
  - runningState
```
StopWatch.State runningState
```
    The current running state of the StopWatch.
  - splitState
```
StopWatch.SplitState splitState
```
    Whether the stopwatch has a split time recorded.
  - startTime
```
private long startTime
```
    The start time.
  - startTimeMillis
```
private long startTimeMillis
```
    The start time in Millis - nanoTime is only for elapsed time so we need to also store the currentTimeMillis to maintain the old getStartTime API.
  - stopTime
```
private long stopTime
```
    The stop time.
- Constructor Detail
  - StopWatch
```
public StopWatch()
```
- Method Detail
  - start
```
public void start()
```
    Start the stopwatch.
    This method starts a new timing session, clearing any previous values.
    
    Throws IllegalStateException if the StopWatch is already running or not started yet.
  - stop
```
public void stop()
```
    Stop the stopwatch.
    This method ends a new timing session, allowing the time to be retrieved.
    
    Throws IllegalStateException if the StopWatch is not running.
  - reset
```
public void reset()
```
    Resets the stopwatch. Stops it if need be.
    This method clears the internal values to allow the object to be reused.
  - split
```
public void split()
```
    Split the time.
    This method sets the stop time of the watch to allow a time to be extracted. The start time is unaffected, enabling unsplit() to continue the timing from the original start point.
    
    Throws IllegalStateException if the StopWatch is not running.
  - unsplit
```
public void unsplit()
```
    Remove a split.
    This method clears the stop time. The start time is unaffected, enabling timing from the original start point to continue.
    
    Throws IllegalStateException if the StopWatch has not been split.
  - suspend
```
public void suspend()
```
    Suspend the stopwatch for later resumption.
    This method suspends the watch until it is resumed. The watch will not include time between the suspend and resume calls in the total time.
    
    Throws IllegalStateException if the StopWatch is not currently running.
  - resume
```
public void resume()
```
    Resume the stopwatch after a suspend.
    This method resumes the watch after it was suspended. The watch will not include time between the suspend and resume calls in the total time.
    
    Throws IllegalStateException if the StopWatch has not been suspended.
  - getTime
```
public long getTime()
```
    Get the time on the stopwatch.
    This is either the time between the start and the moment this method is called, or the amount of time between start and stop.
    
    Returns:
    
    the time in milliseconds
  - getNanoTime
```
public long getNanoTime()
```
    Get the time on the stopwatch in nanoseconds.
    This is either the time between the start and the moment this method is called, or the amount of time between start and stop.
    
    Returns:
    
    the time in nanoseconds
  - getSplitTime
```
public long getSplitTime()
```
    Get the split time on the stopwatch.
    This is the time between start and latest split.
    
    Throws IllegalStateException if the StopWatch has not yet been split.
    
    Returns:
    
    the split time in milliseconds
  - getSplitNanoTime
```
public long getSplitNanoTime()
```
    Get the split time on the stopwatch in nanoseconds.
    This is the time between start and latest split.
    
    Throws IllegalStateException if the StopWatch has not yet been split.
    
    Returns:
    
    the split time in nanoseconds
  - getStartTime
```
public long getStartTime()
```
    Returns the time this stopwatch was started.
    Throws IllegalStateException if this StopWatch has not been started.
    
    Returns:
    
    the time this stopwatch was started
  - toString
```
public String toString()
```
    Gets a summary of the time that the stopwatch recorded as a string.
    The format used is ISO8601-like, hours:minutes:seconds.milliseconds.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    never null or empty
  - toSplitString
```
public String toSplitString()
```
    Gets a summary of the split time that the stopwatch recorded as a string.
    The format used is ISO8601-like, hours:minutes:seconds.milliseconds.
    
    Returns:
    
    the split time as a String
  - isStarted
```
public boolean isStarted()
```
    The method is used to find out if the StopWatch is started. A suspended StopWatch is also started watch.
    
    Returns:
    
    boolean If the StopWatch is started.
  - isSuspended
```
public boolean isSuspended()
```
    This method is used to find out whether the StopWatch is suspended.
    
    Returns:
    
    boolean If the StopWatch is suspended.
  - isStopped
```
public boolean isStopped()
```
    This method is used to find out whether the StopWatch is stopped.
    The stopwatch which's not yet started and explicitly stopped stopwatch is considered as stopped.
    
    Returns:
    
    boolean If the StopWatch is stopped.

Class StopWatch

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DATE_FORMAT

NANO_2_MILLIS

runningState

splitState

startTime

startTimeMillis

stopTime

Constructor Detail

StopWatch

Method Detail

start

stop

reset

split

unsplit

suspend

resume

getTime

getNanoTime

getSplitTime

getSplitNanoTime

getStartTime

toString

toSplitString

isStarted

isSuspended

isStopped