jConsole with Java 1.5

Start java application with the following arguments
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=<port>
-Dcom.sun.management.jmxremote.authenticate=false

Run jconsole from the command line pointing the to PID of the java process

jconsole <PID>

for example
jconsole 1234