66 lines
2.1 KiB
Java
66 lines
2.1 KiB
Java
|
package com.baeldung.compare;
|
||
|
|
|
||
|
|
import java.util.Arrays;
|
||
|
|
import java.util.LinkedHashMap;
|
||
|
|
import java.util.Map;
|
||
|
|
import java.util.function.BiFunction;
|
||
|
|
|
||
|
|
import org.slf4j.Logger;
|
||
|
|
import org.slf4j.LoggerFactory;
|
||
|
|
import org.springframework.boot.context.event.ApplicationReadyEvent;
|
||
|
|
import org.springframework.context.event.EventListener;
|
||
|
|
import org.springframework.stereotype.Component;
|
||
|
|
|
||
|
|
import io.micrometer.core.instrument.Meter;
|
||
|
|
import io.micrometer.core.instrument.MeterRegistry;
|
||
|
|
import io.micrometer.core.instrument.Statistic;
|
||
|
|
|
||
|
|
@Component
|
||
|
|
public class StartupEventHandler {
|
||
|
|
|
||
|
|
// logger, constructor
|
||
|
|
private static Logger logger = LoggerFactory.getLogger(StartupEventHandler.class);
|
||
|
|
|
||
|
|
public StartupEventHandler(MeterRegistry registry) {
|
||
|
|
this.meterRegistry = registry;
|
||
|
|
}
|
||
|
|
|
||
|
|
private String[] METRICS = {
|
||
|
|
"jvm.memory.used",
|
||
|
|
"jvm.classes.loaded",
|
||
|
|
"jvm.threads.live"};
|
||
|
|
|
||
|
|
private String METRIC_MSG_FORMAT = "Startup Metric >> {}={}";
|
||
|
|
|
||
|
|
private MeterRegistry meterRegistry;
|
||
|
|
|
||
|
|
@EventListener
|
||
|
|
public void getAndLogStartupMetrics(
|
||
|
|
ApplicationReadyEvent event) {
|
||
|
|
Arrays.asList(METRICS)
|
||
|
|
.forEach(this::getAndLogActuatorMetric);
|
||
|
|
}
|
||
|
|
|
||
|
|
private void getAndLogActuatorMetric(String metric) {
|
||
|
|
Meter meter = meterRegistry.find(metric).meter();
|
||
|
|
Map<Statistic, Double> stats = getSamples(meter);
|
||
|
|
|
||
|
|
logger.info(METRIC_MSG_FORMAT, metric, stats.get(Statistic.VALUE).longValue());
|
||
|
|
}
|
||
|
|
|
||
|
|
private Map<Statistic, Double> getSamples(Meter meter) {
|
||
|
|
Map<Statistic, Double> samples = new LinkedHashMap<>();
|
||
|
|
mergeMeasurements(samples, meter);
|
||
|
|
return samples;
|
||
|
|
}
|
||
|
|
|
||
|
|
private void mergeMeasurements(Map<Statistic, Double> samples, Meter meter) {
|
||
|
|
meter.measure().forEach((measurement) -> samples.merge(measurement.getStatistic(),
|
||
|
|
measurement.getValue(), mergeFunction(measurement.getStatistic())));
|
||
|
|
}
|
||
|
|
|
||
|
|
private BiFunction<Double, Double, Double> mergeFunction(Statistic statistic) {
|
||
|
|
return Statistic.MAX.equals(statistic) ? Double::max : Double::sum;
|
||
|
|
}
|
||
|
|
}
|