fix cherry-pick #3677 issue (#3699)

hangc0276 · web-flow · commit b454014ca4da · 2022-12-09T15:09:13.000+08:00
Descriptions of the changes in this PR: ### Motivation Fix cherry-pick #3677 issue
diff --git a/bookkeeper-stats-providers/prometheus-metrics-provider/src/main/java/org/apache/bookkeeper/stats/prometheus/PrometheusMetricsProvider.java b/bookkeeper-stats-providers/prometheus-metrics-provider/src/main/java/org/apache/bookkeeper/stats/prometheus/PrometheusMetricsProvider.java
@@ -128,7 +128,7 @@ public void start(Configuration conf) {
         registerMetrics(Gauge.build("jvm_memory_direct_bytes_used", "-").create().setChild(new Child() {
             @Override
             public double get() {
-                return poolMxBeanOp.isPresent() ? poolMxBeanOp.get().getMemoryUsed() : Double.NaN;
+                return getDirectMemoryUsage.get();
             }
         }));
 

Original file line number	Diff line number	Diff line change
`@@ -128,7 +128,7 @@ public void start(Configuration conf) {`
`128`	`128`	`registerMetrics(Gauge.build("jvm_memory_direct_bytes_used", "-").create().setChild(new Child() {`
`129`	`129`	`@Override`
`130`	`130`	`public double get() {`
`131`		`- return poolMxBeanOp.isPresent() ? poolMxBeanOp.get().getMemoryUsed() : Double.NaN;`
	`131`	`+ return getDirectMemoryUsage.get();`
`132`	`132`	`}`
`133`	`133`	`}));`
`134`	`134`