org.apache.commons.lang.time

Class StopWatch

java.lang.Object

org.apache.commons.lang.time.StopWatch

public class StopWatch
extends java.lang.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:

2.0

Constructor Summary

Constructors

Constructor and Description
StopWatch() Constructor.

Method Summary

Modifier and Type	Method and Description
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.
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.
java.lang.String	toSplitString() Gets a summary of the split time that the stopwatch recorded as a string.
java.lang.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

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

StopWatch

public StopWatch()

Constructor.

Method Detail

start

public void start()

Start the stopwatch.

This method starts a new timing session, clearing any previous values.

Throws:

java.lang.IllegalStateException - if the StopWatch is already running.

stop

public void stop()

Stop the stopwatch.

This method ends a new timing session, allowing the time to be retrieved.

Throws:

java.lang.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:

java.lang.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:

java.lang.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:

java.lang.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:

java.lang.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

getSplitTime

public long getSplitTime()

Get the split time on the stopwatch.

This is the time between start and latest split.

Returns:

the split time in milliseconds

Throws:

java.lang.IllegalStateException - if the StopWatch has not yet been split.

Since:

2.1

getStartTime

public long getStartTime()

Returns the time this stopwatch was started.

Returns:

the time this stopwatch was started

Throws:

java.lang.IllegalStateException - if this StopWatch has not been started

Since:

2.4

toString

public java.lang.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 java.lang.Object

Returns:

the time as a String

toSplitString

public java.lang.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

Since:

2.1