Class GaugeWithCallback

java.lang.Object

io.prometheus.metrics.core.metrics.Metric

io.prometheus.metrics.core.metrics.MetricWithFixedMetadata

io.prometheus.metrics.core.metrics.CallbackMetric

io.prometheus.metrics.core.metrics.GaugeWithCallback

All Implemented Interfaces:

Collector

public class GaugeWithCallback
extends CallbackMetric

Example:

MemoryMXBean memoryBean = ManagementFactory.getMemoryMXBean();

GaugeWithCallback.builder()
    .name("jvm_memory_bytes_used")
    .help("Used bytes of a given JVM memory area.")
    .unit(Unit.BYTES)
    .labelNames("area")
    .callback(callback -> {
        callback.call(memoryBean.getHeapMemoryUsage().getUsed(), "heap");
        callback.call(memoryBean.getNonHeapMemoryUsage().getUsed(), "nonheap");
    })
    .register();

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GaugeWithCallback.Builder
static interface	GaugeWithCallback.Callback

Field Summary

Fields

Modifier and Type	Field	Description
private final Consumer<GaugeWithCallback.Callback>	callback

Fields inherited from class MetricWithFixedMetadata

labelNames

Fields inherited from class Metric

constLabels

Constructor Summary

Constructors

Modifier	Constructor	Description
private	GaugeWithCallback(GaugeWithCallback.Builder builder)

Method Summary

Modifier and Type	Method	Description
static GaugeWithCallback.Builder	builder()
static GaugeWithCallback.Builder	builder(PrometheusProperties properties)
GaugeSnapshot	collect()	Called when the Prometheus server scrapes metrics.
MetricType	getMetricType()	Returns the metric type for registration-time validation.

Methods inherited from class CallbackMetric

makeLabels

Methods inherited from class MetricWithFixedMetadata

getLabelNames, getMetadata, getPrometheusName

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Collector

collect, collect, collect

Field Details

callback

private final Consumer<GaugeWithCallback.Callback> callback

Constructor Details

GaugeWithCallback

private GaugeWithCallback(GaugeWithCallback.Builder builder)

Method Details

collect

public GaugeSnapshot collect()

Description copied from interface: Collector

Called when the Prometheus server scrapes metrics.

Specified by:

collect in interface Collector

Specified by:

collect in class Metric

getMetricType

public MetricType getMetricType()

Description copied from interface: Collector

Returns the metric type for registration-time validation.

This is used to prevent different metric types (e.g., Counter and Gauge) from sharing the same name. Returning null means type validation is skipped for this collector.

Validation is performed only at registration time. If this method returns null, no type validation is performed for this collector, and duplicate or conflicting metrics may result in invalid exposition output.

Returns:

the metric type, or null to skip validation

builder

public static GaugeWithCallback.Builder builder()

builder

public static GaugeWithCallback.Builder builder(PrometheusProperties properties)