Java Database Connectivity (JDBC) enable you to call PL/SQL stored functions and procedures. For example, you want to call the following stored function, which returns the balance of a specified bank account:

FUNCTION balance (acct_id NUMBER) RETURN NUMBER IS
acct_bal NUMBER;
BEGIN
SELECT bal INTO acct_bal FROM accts
WHERE acct_no = acct_id;
RETURN acct_bal;
END;

In a JDBC program, a call to the balance function can be written as follows:

...
CallableStatement cstmt = conn.prepareCall("{? = CALL balance(?)}");
cstmt.registerOutParameter(1, Types.FLOAT);
cstmt.setInt(2, acctNo);
cstmt.executeUpdate();
float acctBal = cstmt.getFloat(1);
...