Java and JavaScript in the Database

Please can anybody help with this problem ? I have written java API for sending mails, which works fine, until I loaded it into the database (8.1.7.3). When I call this API from PL/SQL procedure, it works good, it sends mail, but the java code never exits. In the following code test_java_return.testjavareturn; never ends and the package/java classes remain locked. On normal JVM it returns normally. When I try not return from Java, but explicitly throw some Exception, even the exception is not thrown...The only way to exit from java method is to call java.lang.System.exit(), which I can't use, because I want to return some integer from Java code. Thanx very much for any help :)

BEGIN
test_java_return.testjavareturn;
COMMIT;
EXCEPTION
WHEN OTHERS THEN
dbms_output.put_line('Error '||TO_CHAR(SQLCODE)||': '||SQLERRM);
RAISE;
END;