The Bank Example in Aurora and VBJ

The following sections compare implementations of the bank example widely used in VBJ documentation. Both client and server are shown as they would be implemented in Oracle8 i and VBJ. All implementations use inheritance.

The Bank IDL Module

// Bank.idl

module Bank {
  interface Account {
    float balance();
  };
  interface AccountManager {
    Account open(in string name);
  };
};
		  

Aurora Client

// Client.java

import bankServer.*;
import Bank.*;

import oracle.aurora.jndi.sess_iiop.ServiceCtx;

import javax.naming.Context;
import javax.naming.InitialContext;
import java.util.Hashtable;

public class Client
{
  public static void main (String[] args) throws Exception {

    String serviceURL = "sess_iiop://localhost:2222";
    String objectName = "/test/myBank";
    String username = "scott";
    String password = "tiger";
    
    Hashtable env = new Hashtable();
    env.put(Context.URL_PKG_PREFIXES, "oracle.aurora.jndi");
    env.put(Context.SECURITY_PRINCIPAL, username);
    env.put(Context.SECURITY_CREDENTIALS, password);
    env.put(Context.SECURITY_AUTHENTICATION, ServiceCtx.NON_SSL_LOGIN);

    Context ic = new InitialContext(env);

    AccountManager manager = 
      (AccountManager) ic.lookup(serviceURL + objectName);

    // use args[0] as the account name, or a default.
    String name = args.length == 1 ? args[0] : "Jack B. Quick";

    // Request the account manager to open a named account.
    Bank.Account account = manager.open(name);

    // Get the balance of the account.
    float balance = account.balance();

    // Print out the balance.
    System.out.println
      ("The balance in " + name + "`s account is $" + balance);
  }
}

VBJ Client

// Client.java

public class Client {

  public static void main(String[] args) {
    // Initialize the ORB.
    org.omg.CORBA.ORB orb = org.omg.CORBA.ORB.init(args,null);
    // Locate an account manager.
    Bank.AccountManager manager = 
      	Bank.AccountManagerHelper.bind(orb, "BankManager");
    // use args[0] as the account name, or a default.
    String name = args.length > 0 ? args[0] : "Jack B. Quick";
    // Request the account manager to open a named account.
    Bank.Account account = manager.open(name);
      // Get the balance of the account.
    float balance = account.balance();
    // Print out the balance.
    System.out.println
      ("The balance in " + name + "`s account is $" + balance);
  }

}

Aurora Account Implementation

// AccountImpl.java
package bankServer;

public class AccountImpl extends Bank._AccountImplBase {
  public AccountImpl(float balance) {
    _balance = balance;
  }
  public float balance() {
    return _balance;
  }
  private float _balance;
}

VBJ Account Implementation

// AccountImpl.java

public class AccountImpl extends Bank._AccountImplBase {
  public AccountImpl(float balance) {
    _balance = balance;
  }
  public float balance() {
    return _balance;
  }
  private float _balance;
}

Aurora Account Manager Implementation

// AccountManagerImpl.java
package bankServer;

import java.util.*;

public class AccountManagerImpl extends Bank._AccountManagerImplBase {

  public AccountManagerImpl() {
    super();
  }

  public AccountManagerImpl(String name) {
    super(name);
  }

  public synchronized Bank.Account open(String name) {
    // Lookup the account in the account dictionary.
    Bank.Account account = (Bank.Account) _accounts.get(name);
    // If there was no account in the dictionary, create one.
    if(account == null) {

      // Make up the account's balance, between 0 and 1000 dollars.
      float balance = Math.abs(_random.nextInt()) % 100000 / 100f;

      // Create the account implementation, given the balance.
      account = new AccountImpl(balance);

      _orb().connect (account);

      // Print out the new account.
      // This just goes to the system trace file for Aurora.
      System.out.println("Created " + name + "`s account: " + account);

      // Save the account in the account dictionary.
      _accounts.put(name, account);
    }
    // Return the account.
    return account;
  }

  private Dictionary _accounts = new Hashtable();
  private Random _random = new Random();

}

VBJ Account Manager Implementation

// AccountManagerImpl.java

import java.util.*;

public class AccountManagerImpl extends Bank._AccountManagerImplBase {
  public AccountManagerImpl(String name) {
    super(name);
  }
  public synchronized Bank.Account open(String name) {
    // Lookup the account in the account dictionary.
    Bank.Account account = (Bank.Account) _accounts.get(name);
    // If there was no account in the dictionary, create one.
    if(account == null) {
      // Make up the account's balance, between 0 and 1000 dollars.
      float balance = Math.abs(_random.nextInt()) % 100000 / 100f;
      // Create the account implementation, given the balance.
      account = new AccountImpl(balance);
      // Make the object available to the ORB.
      _boa().obj_is_ready(account);
      // Print out the new account.
      System.out.println("Created " + name + "`s account: " + account);
      // Save the account in the account dictionary.
      _accounts.put(name, account);
    }
    // Return the account.
    return account;
  }
  private Dictionary _accounts = new Hashtable();
  private Random _random = new Random();
}

VBJ Server Mainline

// Server.java


public class Server {

  public static void main(String[] args) {
    // Initialize the ORB.
    org.omg.CORBA.ORB orb = org.omg.CORBA.ORB.init(args,null);
    // Initialize the BOA.
    org.omg.CORBA.BOA boa = orb.BOA_init();
    // Create the account manager object.
    Bank.AccountManager manager = 
      new AccountManagerImpl("BankManager");
    // Export the newly created object.
    boa.obj_is_ready(manager);
    System.out.println(manager + " is ready.");
    // Wait for incoming requests
    boa.impl_is_ready();
  }

}

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