Need help w corba/jdbc class

Question

hi
i'm trying to get this class to work right, i don't think i'm coding it the right way, especially the getAllAccounts() and selectAccounts() methods. this code compiles cleanly, but i get runtime exceptions when i try to run my app. my runtime exceptions look like
############################ StackTrace ############################
java.lang.NullPointerException
at com.kafein.accountServices.AccountServiceImpl.getAllAccounts(AccountS
erviceImpl.java:218)
at com.kafein.idl.accountServices.AccountServicePOA._invoke(AccountServi
cePOA.java:74)
at org.jacorb.poa.RequestProcessor.invokeOperation(RequestProcessor.java
:247)
at org.jacorb.poa.RequestProcessor.process(RequestProcessor.java:477)
at org.jacorb.poa.RequestProcessor.run(RequestProcessor.java:604)
and
Creating 100 Accounts
org.omg.CORBA.UNKNOWN: This exception was reported by the server, it is only re-
thrown here. vmcid: 0x0 minor code: 0 completed: No
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Sou
rce)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.jacorb.orb.SystemExceptionHelper.read(SystemExceptionHelper.java:
157)
at org.jacorb.orb.connection.ReplyInputStream.checkExceptions(ReplyInput
Stream.java:117)
at org.jacorb.orb.Delegate.invoke(Delegate.java:942)
at org.omg.CORBA.portable.ObjectImpl._invoke(Unknown Source)
at com.kafein.idl.accountServices._AccountServiceStub.getAllAccounts(_Ac
countServiceStub.java:134)
at com.kafein.client.AccountClient.main(AccountClient.java:111)
org.omg.CORBA.UNKNOWN: This exception was reported by the server, it is only re-
thrown here. vmcid: 0x0 minor code: 0 completed: No
ORB shutting down...
code for this class is below...
// AccountServiceImpl.java: The AccountService Implementation
package com.kafein.accountServices;
import java.util.Hashtable;
import java.util.Calendar;
import java.util.GregorianCalendar;
import junit.framework.TestCase;
import junit.framework.Test;
import junit.framework.TestSuite;
import org.omg.PortableServer.*;
import com.kafein.idl.accountServices.AccountServicePOA;
import com.kafein.idl.accountServices.AccountEntryStruct;
import com.kafein.idl.accountServices.AccountStruct;
import com.kafein.idl.utilities.DateTimeStruct;
import com.kafein.idl.exceptions.NotFoundException;
import com.kafein.idl.exceptions.DataValidationException;
import com.kafein.idl.errorCodes.DataValidationErrorCodes;
import com.kafein.utils.ServiceHandler;
import com.kafein.utils.Log;
import java.net.URL;
import java.sql.*;
import java.util.*;
* AccountServiceImpl is an implementation of the
* idl.accountServices.AccountService interface.
public class AccountServiceImpl extends AccountServicePOA {
  POA poa;
  private Hashtable accounts = new Hashtable(); // collection of Accounts
  private static int nextAccountID = 1; // global account ID
  Connection connection;
  Vector connections;
  Statement statement;
  PreparedStatement preparedStatement;
   * Construct an instance.
  public AccountServiceImpl(POA aPOA, String driver, String url, String user, String password) {
    super();
    poa = aPOA;
    driver = driver;
    url = url;
    user = user;
    password = password;
    connections = new Vector();
    // Connect to Database
    try {
        connect(driver,url,user,password);
    catch(Exception e) {
           e.printStackTrace();       
    // Simple Database Select
    try {
        testSimpleSelect();
    catch(Exception e) {
           e.printStackTrace();       
    // Database Select
    try {
        testSelect();
    catch(Exception e) {
           e.printStackTrace();       
   * Overloaded constructor for unit tests.
  protected AccountServiceImpl() {
    poa = null;
   * createAccount is used by administrator to add a new Account
   * in the system.
   * @param newAccount AccountEntryStruct containing data for new account
   * @return int the new unique Account ID
   * @exception com.kafein.idl.exceptions.DataValidationException
  public int createAccount(AccountEntryStruct newAccount) throws
    DataValidationException {
    validateData (newAccount); // throws DataValidationException;
    int accountID = getNextID();     
    // Create new Account.
    Account anAccount = new Account(accountID,
                        newAccount.userName,
                        newAccount.userEmail,
                        newAccount.creditCardType,
                        newAccount.creditCardNumber,
                        newAccount.creditCardExpirationDate.year,
                        newAccount.creditCardExpirationDate.month,
                        newAccount.userPassword,
                        newAccount.initialBalance);
// Insert here / call method insertAccount() pass it in an account object
// or call manager object - accountmanager.put()
    // Insert Account into Database
    try {
        insertAccount(anAccount);
    catch(Exception e) {
           e.printStackTrace();       
    accounts.put(accountID,anAccount);
    return accountID;
   * isAccountValid is used to validate a user logon.
   * @param accountID AccountID
   * @param userPassword String
   * @return boolean true to indicate an existing Account
  public boolean isValidAccount (int accountID, String userPassword) {
    // Get account with key equal to accountID.
    AccountStruct anAccount;
    try {
      anAccount = (AccountStruct) getAccount (accountID);
    catch (NotFoundException e) {
      return false;
    // Verify password.
    return (anAccount.userPassword.equals(userPassword) ? true : false);
   * getAccount is used to retrieve an existing Account in the system
   * @param int AccountID
   * @return AccountStruct containing data for the existing Account
   * @exception com.kafein.idl.exceptions.NotFoundException
  public AccountStruct getAccount(int accountID)throws
    NotFoundException {
    // Verify that accountID is within an appropriate interval.
    if (accountID < 1 || accountID > accounts.size()) {
      throw new NotFoundException(DataValidationErrorCodes.INVALID_ACCOUNT_ID,
                      "Account ID not found");
    // Get Account and convert to AccountStruct (which is returned).
    Account anAccount = (Account) accounts.get(accountID);
    return anAccount.getAccountStruct();
   * getAllAccounts is used to retrieve all existing Accounts in the system
   * @return AccountStruct[] containing all existing Accounts.
   * @fyi returns an empty sequence if no Accounts exist
  // GetAllAcounts method v. 2 - rather than enumerating through the vector
  // call a method that returns a collection of objs in that method where
  // you do select stmts
  public AccountStruct[] getAllAccounts() {
    // Allocate the array of AccountStructs.
    Vector results = new Vector();
    try {
            results = selectAccounts();
    catch(Exception e) {
           e.printStackTrace();       
    //Vector results = selectAccounts();
    int lastKey = results.size();
    //int lastKey = accounts.size();
    AccountStruct[] accountSequence = new AccountStruct[lastKey];
    if (lastKey==0) {
      return accountSequence;
    // Create AccountStructs from Accounts.
    for (int i = 1; i <= lastKey; i++) {
      Account anAccount = (Account) accounts.get(i);
      accountSequence[i-1] = anAccount.getAccountStruct();
    return accountSequence;
   * validateData is used to check new account data.
   * @param newAccount AccountEntryStruct containing data for new account
   * @exception com.kafein.idl.exceptions.DataValidationException
  protected void validateData(AccountEntryStruct newAccount) throws
    DataValidationException {
    // Check all of the member data in newAccount.
    if (newAccount.userName.equals("")) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_USER_NAME,
          "User Name must not be empty");
    if (newAccount.userEmail.equals("")) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_USER_EMAIL,
          "User Email must not be empty");
    if (newAccount.creditCardType.equals("")) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_CREDIT_CARD_TYPE,
          "Credit card type must not be empty");
    if (newAccount.creditCardNumber.equals("")) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_CREDIT_CARD_NUMBER,
          "Credit card number must not be empty");
    // Compare creditCardExpirationDate to current date
    // (we only consider year and month).
    GregorianCalendar now = new GregorianCalendar();
    DateTimeStruct proposed = newAccount.creditCardExpirationDate;
    if (proposed.year < now.get (Calendar.YEAR) ||
     (proposed.year == now.get (Calendar.YEAR) &&
      proposed.month < now.get (Calendar.MONTH) + 1)) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_CREDIT_CARD_EXPIRATION_DATE,
          "Credit card has expired");
    if (newAccount.userPassword.equals("")) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_USER_PASSWORD,
          "Password must not be empty");
    else if (!newAccount.userPassword.equals(newAccount.userPasswordVerification)) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_USER_PASSWORD,
          "Password verification failure");
    if (newAccount.initialBalance < 0.0F) {
      throw new DataValidationException(
          DataValidationErrorCodes.INVALID_BALANCE,
          "Account Balance cannot have a negative balance");
   * getNextID is used to generate a unique ID.
   * Needs a much better implementation that generates a globally unique ID!
   * @return int an Account ID
  protected synchronized int getNextID() {
    nextAccountID++;
    return nextAccountID - 1;
   * override _default_POA to return this servant's POA, not Root POA
  public POA _default_POA() {
    return poa;
   * jdbc related methods
  public void connect(String driver, String url, String user, String password)
                throws Exception {
        try {
            // Load JDBC driver
            Class.forName(driver);
            System.out.println("Connecting to " + url);
            connection = DriverManager.getConnection(url, user, password);
            connections.add(connection);
            connection.setAutoCommit(false);
        } catch(Exception e) {
            System.err.println("System Exception in connect");
            System.err.println(e);
            throw e;
  public void closeConnection() throws Exception {
        try {
            Enumeration myEnum = connections.elements();
            while ( myEnum.hasMoreElements() ) {
                System.out.println("Closing connection");
                ((Connection) myEnum.nextElement()).close();
        } catch (Exception e) {
            System.err.println("System Exception in closeConnection");
            System.err.println(e);
            throw e;
  private void testSimpleSelect() throws Exception {
        try {
            Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery("Select 1 from ACCOUNT");
            if (rs != null && rs.next()) {
               int value = rs.getInt(1);
               System.out.println("Fetched value " + value);
            connection.commit();
            statement.close();
        } catch(Exception e) {
            System.err.println("System Exception in testSimpleSelect");
            System.err.println(e);
            throw e;
  private void testSelect() throws Exception {
        try {
            Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery(
                "Select ACCT_ID, ACCT_USERNAME, ACCT_USEREMAIL, ACCT_CC_TYPE, ACCT_CC_NUMBER, ACCT_CC_EXPYR, ACCT_CC_EXPMO, ACCT_USERPASSWORD, ACCT_USERBALANCE from ACCOUNT LIMIT 1");
            System.out.println("Account ID   User Name     User Email     CC Type     CC Number     CC Expyr CC Expmo User Password     User Balance");
            while (rs != null && rs.next()) {
                int acct_id = rs.getInt(1);
                String acct_username = rs.getString(2);
                String acct_useremail = rs.getString(3);
                String acct_cc_type = rs.getString(4);
                String acct_cc_number = rs.getString(5);
                int acct_cc_expyr = rs.getInt(6);
                int acct_cc_expmo = rs.getInt(7);
                String acct_userpassword = rs.getString(8);
                float acct_userbalance = rs.getFloat(9);
                System.out.println(acct_id + "         " +
                                   acct_username + "   " +
                                   acct_useremail + "   " +
                                   acct_cc_type + "   " +
                                   acct_cc_number + "   " +
                                   acct_cc_expyr + "   " +
                                   acct_cc_expmo + "   " +
                                   acct_userpassword + "   " +
                                   acct_userbalance);
            connection.commit();
            statement.close();
        } catch(Exception e) {
            System.err.println("System Exception in testSelect");
            System.err.println(e);
            throw e;
  private void testLoadData() throws Exception {
        int numberOfAccounts = 5;
        String  acct_username    = "<--20 BYTE STRING-->";
        String  acct_useremail = "<--20 BYTE STRING-->";
     String  acct_cc_type = "TEST ";
        String  acct_cc_number = "<--20 BYTE STRING-->";
        int  acct_cc_expyr = 2000;
        int  acct_cc_expmo = 1;
        String  acct_userpassword = "<--20 BYTE STRING-->";
        float     acct_userbalance = 0.0F;
        int     acct_id = 0;
     try {
            System.out.println("Inserting data...");
            connection.setAutoCommit(false);
            // Calculate Start time
            System.out.println("Starting data insertion (" + numberOfAccounts +
                " rows) into ACCOUNT table..");
            long startTime = System.currentTimeMillis();
            preparedStatement = connection.prepareStatement(
                "INSERT INTO ACCOUNT (ACCT_ID, ACCT_USERNAME, ACCT_USEREMAIL, ACCT_CC_TYPE, ACCT_CC_NUMBER, " +
                "ACCT_CC_EXPYR, ACCT_CC_EXPMO, ACCT_USERPASSWORD, ACCT_USERBALANCE) VALUES ( ?, ?, ?, ?, ?, ? , ?, ?, ?)");
            // Insert accounts in ACCOUNT table
            for (int i = 1; i <= numberOfAccounts; i++) {
                acct_id  = i * 1000;
                preparedStatement.setInt(1, acct_id);
                preparedStatement.setString(2, acct_username);
                preparedStatement.setString(3, acct_useremail);
                preparedStatement.setString(4, acct_cc_type);
                preparedStatement.setString(5, acct_cc_number);
                preparedStatement.setInt(6, acct_cc_expyr);
                preparedStatement.setInt(7, acct_cc_expmo);
                preparedStatement.setString(8, acct_userpassword);
                preparedStatement.setFloat(9, acct_userbalance);
          preparedStatement.executeUpdate();
                connection.commit();
            System.out.println(numberOfAccounts + " accounts created.");
            preparedStatement.close();
            long stopTime = System.currentTimeMillis();
            System.out.println("Account table load complete.");
            System.out.println("Load time = " +
                               ((stopTime - startTime)/(1000f)) + " seconds");
            System.out.println("Data insertion complete");
        } catch(Exception e) {
            System.err.println("System Exception in loadData");
            System.err.println(e);
            throw e;
   * insertAccount is used to insert a new Account in the Database
   * @param int AccountID
   * @return AccountStruct containing data for the existing Account
  private void insertAccount(Account anAccount) throws Exception {
          AccountStruct anAccountStruct = anAccount.getAccountStruct();  
     int numberOfAccounts = 1;
     String  acct_username    = anAccountStruct.userName;
        String  acct_useremail = anAccountStruct.userEmail;
     String  acct_cc_type = anAccountStruct.creditCardType;
        String  acct_cc_number = anAccountStruct.creditCardNumber;
     int acct_cc_expyr = anAccountStruct.creditCardExpirationDate.year;
        int acct_cc_expmo = anAccountStruct.creditCardExpirationDate.month;
        String  acct_userpassword = anAccountStruct.userPassword;
        float     acct_userbalance = anAccountStruct.accountBalance;
        int     acct_id = anAccountStruct.accountID;
     try {
            System.out.println("Inserting data...");
            connection.setAutoCommit(false);
//instead of system.out just log
            // Calculate Start time
            System.out.println("Starting data insertion ( 1" +
                " row) into ACCOUNT table..");
            long startTime = System.currentTimeMillis();
            preparedStatement = connection.prepareStatement(
                "INSERT INTO ACCOUNT (ACCT_ID, ACCT_USERNAME, ACCT_USEREMAIL, ACCT_CC_TYPE, ACCT_CC_NUMBER, " +
                "ACCT_CC_EXPYR, ACCT_CC_EXPMO, ACCT_USERPASSWORD, ACCT_USERBALANCE) VALUES ( ?, ?, ?, ?, ?, ? , ?, ?, ?)");
                acct_id  = 1000;
                preparedStatement.setInt(1, acct_id);
                preparedStatement.setString(2, acct_username);
                preparedStatement.setString(3, acct_useremail);
                preparedStatement.setString(4, acct_cc_type);
                preparedStatement.setString(5, acct_cc_number);
                preparedStatement.setInt(6, acct_cc_expyr);
                preparedStatement.setInt(7, acct_cc_expmo);
                preparedStatement.setString(8, acct_userpassword);
                preparedStatement.setFloat(9, acct_userbalance);
          preparedStatement.executeUpdate();
                connection.commit();
            System.out.println("1 account created.");
            preparedStatement.close();
            long stopTime = System.currentTimeMillis();
            System.out.println("Account table load complete.");
            System.out.println("Load time = " +
                               ((stopTime - startTime)/(1000f)) + " seconds");
            System.out.println("Data insertion complete");
        } catch(Exception e) {
            System.err.println("System Exception in loadData");
            System.err.println(e);
            throw e;
  private Vector selectAccounts() throws Exception {
        try {
            // Create Vector to hold individual Account values
         Vector mainvector = new Vector();
         Vector values = new Vector();
         Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery(
                "Select ACCT_ID, ACCT_USERNAME, ACCT_USEREMAIL, ACCT_CC_TYPE, ACCT_CC_NUMBER, ACCT_CC_EXPYR, ACCT_CC_EXPMO, ACCT_USERPASSWORD, ACCT_USERBALANCE from ACCOUNT");
            System.out.println("Account ID   User Name     User Email     CC Type     CC Number     CC Expyr CC Expmo User Password     User Balance");
         // Iterate through result set
         while (rs != null && rs.next()) {
          // Make sure values is empty
          values.clear();
          int acct_id = rs.getInt(1);
                String acct_username = rs.getString(2);
                String acct_useremail = rs.getString(3);
                String acct_cc_type = rs.getString(4);
                String acct_cc_number = rs.getString(5);
                int acct_cc_expyr = rs.getInt(6);
                int acct_cc_expmo = rs.getInt(7);
                String acct_userpassword = rs.getString(8);
                float acct_userbalance = rs.getFloat(9);
          // Populate Vector values
          values.addElement(rs.getObject(1));
          values.addElement(rs.getObject(2));
          values.addElement(rs.getObject(3));
          values.addElement(rs.getObject(4));
          values.addElement(rs.getObject(5));
          values.addElement(rs.getObject(6));
          values.addElement(rs.getObject(7));
          values.addElement(rs.getObject(8));
          values.addElement(rs.getObject(9));
          mainvector.addElement(values);
                System.out.println(acct_id + "         " +
                                   acct_username + "   " +
                                   acct_useremail + "   " +
                                   acct_cc_type + "   " +
                                   acct_cc_number + "   " +
                                   acct_cc_expyr + "   " +
                                   acct_cc_expmo + "   " +
                                   acct_userpassword + "   " +
                                   acct_userbalance);
            connection.commit();
            statement.close();
         return mainvector;
        } catch(Exception e) {
            System.err.println("System Exception in selectAccounts");
            System.err.println(e);
            throw e;
    }

Answer 1

line 217 and 218 is
Account anAccount = (Account) accounts.get(i);
accountSequence[i-1] = anAccount.getAccountStruct();
i realized that
Account anAccount = (Account) accounts.get(i);
was a typo. what it should have been was
Account anAccount = (Account) results.get(i);
so my getAllAccounts() method now looks like
   * getAllAccounts is used to retrieve all existing Accounts in the system
   * @return AccountStruct[] containing all existing Accounts.
   * @fyi returns an empty sequence if no Accounts exist
  // GetAllAcounts method v. 2 - rather than enumerating through the vector
  // call a method that returns a collection of objs in that method where
  // you do select stmts
  public AccountStruct[] getAllAccounts() {
    // Allocate the array of AccountStructs.
    Vector results = new Vector();
    try {
            results = selectAccounts();
    catch(Exception e) {
           e.printStackTrace();       
    //Vector results = selectAccounts();
    int lastKey = results.size();
    //int lastKey = accounts.size();
    AccountStruct[] accountSequence = new AccountStruct[lastKey];
    if (lastKey==0) {
      return accountSequence;
    // Create AccountStructs from Accounts.
    for (int i = 1; i <= lastKey; i++) {
      Account anAccount = (Account) results.get(i);
      accountSequence[i-1] = anAccount.however, i still get the same runtime errors.
is my selectAccounts() method returning a null?