org.springframework.util
Class StopWatch

java.lang.Object
  extended byorg.springframework.util.StopWatch

public class StopWatch
extends Object

Simple stop watch, allowing for timing of a number of tasks, exposing total running time and running time for each named task. Conceals use of System.currentTimeMillis(), improving the readability of application code and reducing the likelihood of calculation errors.

Note that this object is not designed to be threadsafe, and does not use synchronization or threading. Therefore it is safe to invoke it from EJBs.

This class is normally used to verify performance during proof-of-concepts and in development, rather than as part of production applications.

Since:
May 2, 2001
Author:
Rod Johnson

Nested Class Summary
static class StopWatch.TaskInfo
          Inner class to hold data about one task executed within the stop watch.
 
Constructor Summary
StopWatch()
          Construct a new stop watch.
StopWatch(String id)
          Construct a new stop watch with the given id.
 
Method Summary
 long getLastInterval()
          Deprecated. in favor of getLastTaskTimeMillis
 long getLastTaskTimeMillis()
          Return the time taken by the last task.
 int getTaskCount()
          Return the number of tasks timed.
 StopWatch.TaskInfo[] getTaskInfo()
          Return an array of the data for tasks performed.
 long getTotalTime()
          Deprecated. in favor of getTotalTimeMillis
 long getTotalTimeMillis()
          Return the total time in milliseconds for all tasks.
 double getTotalTimeSeconds()
          Return the total time in seconds for all tasks.
 double getTotalTimeSecs()
          Deprecated. in favor of getTotalTimeSeconds
 boolean isRunning()
          Return whether the stop watch is currently running.
 String prettyPrint()
          Return a string with a table describing all tasks performed.
 void setKeepTaskList(boolean keepTaskList)
          Determine whether the TaskInfo array is built over time.
 String shortSummary()
          Return a short description of the total running time.
 void start(String taskName)
          Start a named task.
 void stop()
          Stop the current task.
 String toString()
          Return an informative string describing all tasks performed For custom reporting, call getTaskInfo() and use the task info directly.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

StopWatch

public StopWatch()
Construct a new stop watch. Does not start any task.


StopWatch

public StopWatch(String id)
Construct a new stop watch with the given id. Does not start any task.

Parameters:
id - identifier for this stop watch. Handy when we have output from multiple stop watches and need to distinguish between them.
Method Detail

setKeepTaskList

public void setKeepTaskList(boolean keepTaskList)
Determine whether the TaskInfo array is built over time. Set this to false when using a StopWatch for millions of intervals, or the task info structure will consume excessive memory. Default is true.


start

public void start(String taskName)
           throws IllegalStateException
Start a named task. The results are undefined if stop or timing methods are called without invoking this method.

Parameters:
taskName - the name of the task to start
Throws:
IllegalStateException
See Also:
stop()

stop

public void stop()
          throws IllegalStateException
Stop the current task. The results are undefined if timing methods are called without invoking at least one pair start/stop methods.

Throws:
IllegalStateException
See Also:
start(java.lang.String)

isRunning

public boolean isRunning()
Return whether the stop watch is currently running.


getLastTaskTimeMillis

public long getLastTaskTimeMillis()
                           throws IllegalStateException
Return the time taken by the last task.

Throws:
IllegalStateException

getLastInterval

public long getLastInterval()
                     throws IllegalStateException
Deprecated. in favor of getLastTaskTimeMillis

Return the time taken by the last task.

Throws:
IllegalStateException

getTotalTimeMillis

public long getTotalTimeMillis()
Return the total time in milliseconds for all tasks.


getTotalTime

public long getTotalTime()
Deprecated. in favor of getTotalTimeMillis

Return the total time in milliseconds for all tasks.


getTotalTimeSeconds

public double getTotalTimeSeconds()
Return the total time in seconds for all tasks.


getTotalTimeSecs

public double getTotalTimeSecs()
Deprecated. in favor of getTotalTimeSeconds

Return the total time in seconds for all tasks.


getTaskCount

public int getTaskCount()
Return the number of tasks timed.


getTaskInfo

public StopWatch.TaskInfo[] getTaskInfo()
Return an array of the data for tasks performed.


shortSummary

public String shortSummary()
Return a short description of the total running time.


prettyPrint

public String prettyPrint()
Return a string with a table describing all tasks performed. For custom reporting, call getTaskInfo() and use the task info directly.


toString

public String toString()
Return an informative string describing all tasks performed For custom reporting, call getTaskInfo() and use the task info directly.



Copyright (C) 2003-2004 The Spring Framework Project.