J2ME is not a RTOS (Real Time Operating System). It is unlikely that most J2ME profiles or implementations will be usable in this way. There is some
Java RTOS work, but until now it's been pretty independent of J2ME.
Sun's been talking for years about RTOS, but didn't make much progress. Recently the first JSR was for RTOS (
http://java.sun.com/aboutJava/communityprocess/jsr/jsr_001_real_time.html) but I don't know how many companies have implemented it. IMHO Java makes less sense in the embedded space.
--Mark
hershey@eyeshake.com