Requirements dicatate sometime that you use stored proceedures in java

take a look at thsi examples................

1) suppose you wnat to get a time to the nearest micro second
then pl/sql cant help you .you need to use java.....

2)suppose you need to execute a host command within your code even in this case you need to use java coz currently you cant execute a host command from pl/sql

there could be many more such examples....probably someone else would post them here