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javadropwizard

Java Timer logic

This is some code which i found where we need to measure the query execution time for each queries ? For measuring that metricRegistry.timer is used but how it works which time it measures as i can't find any line of code which define stop time it just this line? can anybody help me with that can't find anything on the internet ?

 try (PreparedStatement ps = connection.prepareStatement(QUERY.SQL())) {
          try (
               Timer.Context ignored = metricRegistry.timer(name("query", QUERY.NAME())).time();
               ResultSet rs = ps.executeQuery()) {
            if (rs.next()) {
              successCounter.inc();
            } else {
              failedCounter.inc();
            }
          }
        }
Solution

  • A Timer.Context is a Closeable, which means that when you use it in a try block like you have here, its close() method is called when the try block is exited. Furthermore, per the Javadocs for Timer.Context (https://metrics.dropwizard.io/3.1.0/apidocs/com/codahale/metrics/Timer.Context.html), calling close() is like calling stop(). So basically, stop() is called on the timer when the try block is exited.