How do I time a method's execution in Java?

Question

1. How do I get a method\'s execution time?
2. Is there a Timer utility class for things like timing how long a task takes, etc?

Mos

Answer 1

You can use Metrics library which provides various measuring instruments. Add dependency:

    
        io.dropwizard.metrics
        metrics-core
        ${metrics.version}
    

And configure it for your environment.

Methods can be annotated with @Timed:

@Timed
public void exampleMethod(){
    // some code
}

or piece of code wrapped with Timer:

final Timer timer = metricsRegistry.timer("some_name");
final Timer.Context context = timer.time();
// timed code
context.stop();

Aggregated metrics can exported to console, JMX, CSV or other.

@Timed metrics output example:

com.example.ExampleService.exampleMethod
             count = 2
         mean rate = 3.11 calls/minute
     1-minute rate = 0.96 calls/minute
     5-minute rate = 0.20 calls/minute
    15-minute rate = 0.07 calls/minute
               min = 17.01 milliseconds
               max = 1006.68 milliseconds
              mean = 511.84 milliseconds
            stddev = 699.80 milliseconds
            median = 511.84 milliseconds
              75% <= 1006.68 milliseconds
              95% <= 1006.68 milliseconds
              98% <= 1006.68 milliseconds
              99% <= 1006.68 milliseconds
            99.9% <= 1006.68 milliseconds