Usage: jstack [-l] (to connect to running process) jstack -F [-m] [-l] (to connect to a hung process) jstack [-m] [-l] (to connect to a core file) jstack [-m] [-l] [server_id@] (to connect to a remote debug server) Options: -F to force a thread dump. Use when jstack does not respond (process is hung) -m to print both java and native frames (mixed mode) -l long listing. Prints additional information about locks -h or -help to print this help message