As mentioned on QuickStart page , Stopwatch is very simple to use. Here is very basic example:
Stopwatch.setActive(true);
long id = Stopwatch.start("my group", "my label");
// some code to be measured
Stopwatch.stop(id);
Report report = Stopwatch.getSingleReport("my group", "my label");
System.out.print(report);
Since version 0.4, for people who prefer objects over primitive types, there is Meter object. The following code does exactly the same as the one above, so if you don't mind creating new object on every call, you may find this more convenient way
Stopwatch.setActive(true);
Meter m = Stopwatch.startMeter("my group", "my label");
// some code to be measured
m.stop();
Report report = Stopwatch.getSingleReport("my group", "my label");
System.out.print(report);
Sometimes there is a need to skip some measurements. For example one may not want to measure situations where an exception is thrown. Here is simple example of how to generete different reports for even and odd iterations of the loop:
Stopwatch.setActive(true);
for (int count = 0; count < 21; count++) {
long odd_id = Stopwatch.start("my group", "odd");
long even_id = Stopwatch.start("my group", "even");
// .....
if (count % 2 == 0) {
Stopwatch.skip(odd_id)
Stopwatch.stop(even_id);
} else {
Stopwatch.skip(even_id)
Stopwatch.stop(odd_id);
}
}
Report[] reports = Stopwatch.getGroupReports("my group");
System.out.print(reports[0] + "\n" + reports[1]);
As of version 0.3 there are new methods providing load reports. Load report is one that says how many instances of given measured code were running at given time interval. For example to see how many times measured code in group "g" labeled "l" was executed per minute in last 30 minutes, one could use:
long[] load = Stopwatch.getLoad("g", "l", Calendar.MINUTE, 30);
In this case load[0] will contain the number of code instances running 30 minutes ago and load[29] number of code instances running in the last minute.