《精通EJB》里面的BMP出错。救命啊！！

Question

pstmt = conn.prepareStatement("select ownerName, balance from accounts where id = ?",java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);

Answer 1

这是客户端的程序
public class AccountClient {        public static void main(String[] args) throws Exception {                Account account = null;                try {
                        /*
                         * Get a reference to the Account Home Object - the
                         * factory for Account EJB Objects
                         */
                        Context ctx = new InitialContext(System.getProperties());                        Object obj = ctx.lookup("AccountHome");
                        AccountHome home = (AccountHome) javax.rmi.PortableRemoteObject.narrow(obj, AccountHome.class);                        System.err.println("Total of all accounts in bank initially = " + home.getTotalBankValue());                        /*
                         * Use the factory to create the Account EJB Object
                         */
                        home.create("123-456-7890", "John Smith");                        /*
                         * Find an account
                         */
                        Iterator i = home.findByOwnerName("John Smith").iterator();
                        if (i.hasNext()) {
                          account = (Account)
                            javax.rmi.PortableRemoteObject.narrow(
                              i.next(), Account.class);                        }
                        else {
                                throw new Exception("Could not find account");
                        }                        /*
                         * Call the balance() method, and print it
                         */
                        System.out.println("Initial Balance = " + account.getBalance());                        /*
                         * Deposit $100 into the account
                         */
                        account.deposit(100);                        /*
                         * Retrieve the resulting balance.
                         */
                        System.out.println("After depositing 100, account balance = " + account.getBalance());                        System.out.println("Total of all accounts in bank now = " + home.getTotalBankValue());                        /*
                         * Retrieve the Primary Key from the EJB Object
                         */
                        AccountPK pk = (AccountPK) account.getPrimaryKey();                        /*
                         * Release our old EJB Object reference.  Now call
                         * find() again, this time querying on Account ID
                         * (i.e. the Primary Key).
                         */
                        account = null;
                        account = home.findByPrimaryKey(pk);                        /*
                         * Print out current balance
                         */
                        System.out.println("Found account with ID " + pk + ".  Balance = " + account.getBalance());                        /*
                         * Try to withdraw $150
                         */
                        System.out.println("Now trying to withdraw $150, which is more than is currently available.  This should generate an exception..");
                        account.withdraw(150);                }
                catch (Exception e) {
                        System.out.println("Caught exception!");
                        e.printStackTrace();
                }
                finally {
                        /*
                         * Destroy the Entity permanently
                         */
                        try {
                                System.out.println("Destroying account..");
                                if (account != null) {
                                        account.remove();
                                }
                        }
                        catch (Exception e) {
                                e.printStackTrace();
                        }
                }
        }
}

Answer 2

你查看你完整的客户端程序
 examples.AccountClient.main(AccountClient.java:102)
第102行。