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

We are using AspectJ and Java annotations for this purpose. If we need to know to execution time for a method, we simple annotate it. A more advanced version could use an own log level that can enabled and disabled at runtime.

public @interface Trace {
  boolean showParameters();
}

@Aspect
public class TraceAspect {
  [...]
  @Around("tracePointcut() && @annotation(trace) && !within(TraceAspect)")
  public Object traceAdvice ( ProceedingJintPoint jP, Trace trace ) {

    Object result;
    // initilize timer

    try { 
      result = jp.procced();
    } finally { 
      // calculate execution time 
    }

    return result;
  }
  [...]
}