This article explains what a Java thread dump is, describes multiple ways to generate it—including JDK command‑line tools like jstack and jcmd, OS signals such as kill ‑3, and programmatic access via ThreadMXBean—provides syntax, options, examples, and recommendations for choosing the appropriate method.
This guide walks through using JDK's native command‑line and GUI utilities—such as jps, jinfo, jvisualvm, jstat, jstack, and jcmd—to monitor JVM performance, inspect GC behavior, analyze thread dumps, and troubleshoot memory configuration problems in Java programs.
jcmd, introduced in JDK 7, is a powerful built‑in Java diagnostic tool that lets you send commands to running JVMs, replace utilities like jstack and jmap, and perform tasks such as listing processes, printing thread stacks, retrieving heap information, and using Java Flight Recorder.
This guide explains multiple ways to capture Java heap dumps—including jmap, JVM flags, jcmd, JVisualVM, JMX, and programmatic methods—detailing command syntax, best‑practice options, and step‑by‑step procedures for effective memory‑issue diagnosis.
