Can can one point me what is the environment variable gone wrong here,

JAVA_HOME=/usr/java14_64

1)javac $INSTANCE_HOME/sqllib/samples/java/db2JDBCVersion.java
2)java $INSTANCE_HOME/sqllib/samples/java/db2JDBCVersion dbname db username passwd

It should get you the output as 'IBM DB2 JDBC '. But for me the o/p is "Bad DB2 JDBC Environment; please run usejdbc1 or rusejdbc2 again and chekc fr errors.

have a look : I could reproduce your problem
db2inst1:/export/home/db2inst1: LD_LIBRARY_PATH=/opt/SMAW/lib:/export/home/db2inst1/sqllib/lib32:/opt/IBM/DB2RecoveryExpert/lib^C
db2inst1:/export/home/db2inst1: unset LD_LIBRARY_PATH
db2inst1:/export/home/db2inst1: java db2JDBCVersion
Bad DB2 JDBC environment; please run usejdbc1 or usejdbc2 again and check for errors.
include /export/home/db2inst1/sqllib/lib32 or your lib path after db2 installation

Best Regards, Guy Przytula