To get the heap information a Java process.

java-process-memory-info.sh

#!/bin/bash
PID=$1
if [[ -z "${PID}" ]]; then
    echo "Please provide the process id"
    exit 1
fi

SIZE=`jstat -gc $PID | tail -1 | awk '{split($0,a," "); sum=(a[1]+a[2]+a[5]+a[7])/1024; print sum"MB"}'`
if [[ -z "$SIZE" ]]; then
    exit 1
fi

USED=`jstat -gc $PID | tail -1 | awk '{split($0,a," "); sum=(a[3]+a[4]+a[6]+a[8])/1024; print sum"MB"}'`
MAX=`jstat -gccapacity $PID | tail -1 | awk '{split($0,a," "); sum=(a[2]+a[8])/1024; print sum"MB"}'`
CPU=`ps -p $PID -o %cpu | tail -1`

echo " Max Heap | Current Heap | Used Heap | CPU%"
echo "--------------------------------------------------"
printf "%-9s | %-12s | %-9s | %s\n\n" $MAX $SIZE $USED $CPU