SimpleJdbcCall adder = new SimpleJdbcCall(mockDataSource).withFunctionName("add_invoice");
adder.declareParameters(new SqlOutParameter("return", Types.INTEGER),
new SqlParameter("amount", Types.INTEGER),
new SqlParameter("custid", Types.INTEGER));
Number newId = adder.executeFunction(Number.class, new MapSqlParameterSource()
.addValue("amount", amount)
.addValue("custid", custid));
assertEquals(4, newId.intValue());
}