Prints java stack traces of java threads eating the CPU

java-cpu-monitor.sh

#!/bin/bash                                                                                                                           

threshold=${1-95}
now=$(date '+%Y-%m-%d %H:%M:%S')
cache=()

jps -q | xargs ps hH k -pcpu o pid,lwp,pcpu,args \
  | awk "\$3 >= $threshold" | while read line; do

  array=($(echo "$line"))
  pid=${array[0]}
  lwp=$(printf '%#x' ${array[1]})

  if [ -z "${cache[$pid]}" ]; then
    cache[$pid]=$(jstack $pid)
  fi

  echo "[$now] ${line}"
  echo
  echo "${cache[$pid]}" | sed -n "/nid=$lwp/,/^$/p"
  echo

done