null checks
null checks

(cherry picked from commit f74e8ff487ef32ac8b5f9e3795f3f13d407ab9cf)
Signed-off-by: Olaf Lessenich <09dc7d5025e152d90232b58d4c490220fe4b9097@fim.uni-passau.de>

shuiblue/JDimeForCpp,shuiblue/JDimeForCpp,shuiblue/JDimeForCpp