Here, I wanted to find out how many java.net.HttpClient objects were
created in the JVM. I sorted on the second column which is the number
of objects, giving me all Httpclient related objects, sorted
descending on count:
$ jmap -histo $(pidof java) | sort -k 2 -V | grep net.http.HttpClient
This produced the following listing:
711: 17 272 jdk.internal.net.http.HttpClientImpl$$Lambda$189/0x00000008401be840 (java.net.http@11.0.12)
544: 28 448 jdk.internal.net.http.HttpClientImpl$SelectorAttachment$$Lambda$190/0x00000008401bec40 (java.net.http@11.0.12)
545: 28 448 jdk.internal.net.http.HttpClientImpl$SelectorManager$$Lambda$191/0x00000008401bf040 (java.net.http@11.0.12)
546: 28 448 jdk.internal.net.http.HttpClientImpl$SelectorManager$$Lambda$193/0x00000008401bfc40 (java.net.http@11.0.12)
547: 28 448 jdk.internal.net.http.HttpClientImpl$SelectorManager$$Lambda$195/0x00000008401c4040 (java.net.http@11.0.12)
462: 28 672 jdk.internal.net.http.HttpClientImpl$SelectorManager$$Lambda$192/0x00000008401bf840 (java.net.http@11.0.12)
1744: 1 16 jdk.internal.net.http.HttpClientImpl$SelectorManager$$Lambda$196/0x00000008401c4440 (java.net.http@11.0.12)
1742: 1 16 jdk.internal.net.http.HttpClientImpl$$Lambda$122/0x000000084013e440 (java.net.http@11.0.12)
1743: 1 16 jdk.internal.net.http.HttpClientImpl$$Lambda$123/0x000000084013d840 (java.net.http@11.0.12)
1425: 1 24 [Ljava.net.http.HttpClient$Version; (java.net.http@11.0.12)
1323: 1 32 [Ljava.net.http.HttpClient$Redirect; (java.net.http@11.0.12)
727: 2 256 jdk.internal.net.http.HttpClientImpl (java.net.http@11.0.12)
411: 2 800 jdk.internal.net.http.HttpClientImpl$SelectorManager (java.net.http@11.0.12)
1381: 2 32 jdk.internal.net.http.HttpClientFacade (java.net.http@11.0.12)
1382: 2 32 jdk.internal.net.http.HttpClientImpl$$Lambda$120/0x000000084013ec40 (java.net.http@11.0.12)
1201: 2 48 java.net.http.HttpClient$Version (java.net.http@11.0.12)
1222: 2 48 jdk.internal.net.http.HttpClientImpl$DefaultThreadFactory (java.net.http@11.0.12)
1223: 2 48 jdk.internal.net.http.HttpClientImpl$DelegatingExecutor (java.net.http@11.0.12)
1125: 2 64 jdk.internal.net.http.HttpClientImpl$SSLDirectBufferSupplier (java.net.http@11.0.12)
1074: 3 72 java.net.http.HttpClient$Redirect (java.net.http@11.0.12)
898: 4 128 jdk.internal.net.http.HttpClientImpl$SelectorAttachment (java.net.http@11.0.12)
