For a procedure "a" with two IN parameters (of types VARCHAR2 and NUMBER respectively) and one OUT parameter (type NUMBER), the JSP call would look like:
<% CallableStatement storedProc = conn.prepareCall("{ call a(?,?,?) }");%>
<% storedProc.registerOutParameter(3,Types.INTEGER);%>
<% storedProc.setString(1,param1); %>
<% storedProc.setInt(2,param2); %>
<% try { storedProc.execute();
outParam = storedProc.getInt(3);}
catch (SQLException sqlEx) {
out.println("Error occured! ");
out.println(sqlEx.getMessage());
}%>