Example Code: CORBA

IFR Example

The following example shows how to use the IFR. Soft copy is located at demo/corba/basic/bankWithIFR.

Bank.IDL

// Bank.idl

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

Server

The server code is implemented in the AccountManager, Account, and TIE classes.

AccountManagerImpl.java

package bankServer;

import java.util.*;

public class AccountManagerImpl
  extends Bank._AccountManagerImplBase {

  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 Oracle 8i.
      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();

}

AccountImpl.java

package bankServer;

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

AccountManagerImplTie.java

package bankServer;

import java.util.*;
import oracle.aurora.AuroraServices.ActivatableObject;


public class AccountManagerImplTie
  implements Bank.AccountManagerOperations, 
  ActivatableObject {


  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);

      org.omg.CORBA.ORB.init().BOA_init().obj_is_ready(account);

      // Print out the new account.
      // This just goes to the system trace file for Oracle 8i.
      System.out.println("Created " + name + "'s account: " + account);

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

  public org.omg.CORBA.Object _initializeAuroraObject () {
    return new Bank._tie_AccountManager(this);
  }

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

}

Client

The client code is facilitated in the following:

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;
import org.omg.CORBA.Repository;

public class Client
{
  public static void main (String[] args) throws Exception {
    if (args.length != 5) {
      System.out.println("usage: Client serviceURL objectName user password "
			 + "accountName");
      System.exit(1);
    }
    String serviceURL = args [0];
    String objectName = args [1];
    String user = args [2];
    String password = args [3];
    String name = args [4];

    Hashtable env = new Hashtable();
    env.put(Context.URL_PKG_PREFIXES, "oracle.aurora.jndi");
    env.put(Context.SECURITY_PRINCIPAL, user);
    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);

    // 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);

    System.out.println("Calling the implicit method get_interface()");
    org.omg.CORBA.InterfaceDef intf = (org.omg.CORBA.InterfaceDef)
                             account._get_interface_def();
    System.out.println("intf = " + intf.name());

    System.out.println("Now explicitly looking up for IFR and printing the");
    System.out.println("whole repository");
    System.out.println("");

    Repository rep = (Repository)ic.lookup(serviceURL + "/etc/ifr");

    new PrintIDL(org.omg.CORBA.ORB.init()).print(rep);

  }
}

PrintIDL.java

import java.io.PrintStream;
import java.util.Vector;
import java.io.DataInputStream;
import org.omg.CORBA.Repository;

public class PrintIDL
{
  private static org.omg.CORBA.ORB _orb;
  private static PrintStream _out = System.out;
  private static int _indent;

  
  public PrintIDL (org.omg.CORBA.ORB orb) {
    _orb = orb;
  }
  private void println(Object o) {
    for(int i = 0; i < _indent; i++) {
      _out.print("  ");
    }
    _out.println(o);
  }    

  private String toIdl(org.omg.CORBA.IDLType idlType) {
    org.omg.CORBA.Contained contained = 
org.omg.CORBA.ContainedHelper.narrow(idlType);
    return contained == null ? 
      idlType.type().toString() :
      contained.absolute_name();
  }

  public void print(org.omg.CORBA.Container container) throws 
org.omg.CORBA.UserException {
    org.omg.CORBA.Contained[] contained = 
      container.contents(org.omg.CORBA.DefinitionKind.dk_all, true);
    for(int i = 0; i < contained.length; i++) {
      {
	org.omg.CORBA.ContainedPackage.Description description = 

		contained[i].describe();
	org.omg.CORBA.portable.OutputStream output = 

		_orb.create_output_stream();
	org.omg.CORBA.ContainedPackage.DescriptionHelper.write(output, 

		description);
	org.omg.CORBA.portable.InputStream input = 

		output.create_input_stream();
	org.omg.CORBA.ContainedPackage.Description description2 = 
	  org.omg.CORBA.ContainedPackage.DescriptionHelper.read(input);
	org.omg.CORBA.Any any1 = _orb.create_any();
	org.omg.CORBA.ContainedPackage.DescriptionHelper.insert(any1, 

		description);
	org.omg.CORBA.Any any2 = _orb.create_any();
	org.omg.CORBA.ContainedPackage.DescriptionHelper.insert(any2, 

		description2);	
	if(!any1.equals(any1) ||
	   !any1.equals(any2) ||
	   !any2.equals(any2) ||
	   !any2.equals(any1)) {
	  System.out.println("\n*** The desriptions were not equal (1) *** 
\n");
	}
	org.omg.CORBA.ContainedPackage.Description description3 = 
	  org.omg.CORBA.ContainedPackage.DescriptionHelper.extract(any2);
	if(description.kind != description2.kind ||
	   !description.value.equals(description3.value)) {
	  System.out.println("\n*** The desriptions were not equal (2) *** 
\n");
	}
      }
      switch(contained[i].def_kind().value()) {
      case org.omg.CORBA.DefinitionKind._dk_Attribute:
	printAttribute(org.omg.CORBA.AttributeDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Constant:
	printConstant(org.omg.CORBA.ConstantDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Exception:
	printException(org.omg.CORBA.ExceptionDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Interface:
	printInterface(org.omg.CORBA.InterfaceDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Module:
	printModule(org.omg.CORBA.ModuleDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Operation:
	printOperation(org.omg.CORBA.OperationDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Alias:
	printAlias(org.omg.CORBA.AliasDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Struct:
	printStruct(org.omg.CORBA.StructDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Union:
	printUnion(org.omg.CORBA.UnionDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_Enum:
	printEnum(org.omg.CORBA.EnumDefHelper.narrow(contained[i]));
	break;
      case org.omg.CORBA.DefinitionKind._dk_none:
      case org.omg.CORBA.DefinitionKind._dk_all:
      case org.omg.CORBA.DefinitionKind._dk_Typedef:
      case org.omg.CORBA.DefinitionKind._dk_Primitive:
      case org.omg.CORBA.DefinitionKind._dk_String:
      case org.omg.CORBA.DefinitionKind._dk_Sequence:
      case org.omg.CORBA.DefinitionKind._dk_Array:
      default:
	break;
      }
    }
  }
  
  private void printConstant(org.omg.CORBA.ConstantDef def) throws 

	org.omg.CORBA.UserException {
    println("const " + toIdl(def.type_def()) + " " + def.name() + " = " + 

	def.value() + ";");
  }

  private void printStruct(org.omg.CORBA.StructDef def) throws 

	org.omg.CORBA.UserException {
    println("struct " + def.name() + " {");
    _indent++;
    org.omg.CORBA.StructMember[] members = def.members();
    for(int j = 0; j < members.length; j++) {
      println(toIdl(members[j].type_def) + " " + members[j].name + ";");
    }
    _indent--;
    println("};");    
  }

  private void printUnion(org.omg.CORBA.UnionDef def) throws 
org.omg.CORBA.UserException {
    println("union " + def.name() + " switch(" + 
toIdl(def.discriminator_type_def()) + ") {");
    org.omg.CORBA.UnionMember[] members = def.members();
    int default_index = def.type().default_index();
    _indent++;
    for(int j = 0; j < members.length; j++) {
      if(j == default_index) {
	println("default:");
      }
      else {
	println("case " + members[j].label + ":");
      }
      _indent++;
      println(toIdl(members[j].type_def) + " " + members[j].name + ";");
      _indent--;	  
    }
    _indent--;
    println("};");
  }

  private void printException(org.omg.CORBA.ExceptionDef def) throws 

	org.omg.CORBA.UserException {
    println("exception " + def.name() + " {");
    _indent++;
    org.omg.CORBA.StructMember[] members = def.members();
    for(int j = 0; j < members.length; j++) {
      println(toIdl(members[j].type_def) + " " + members[j].name + ";");
    }
    _indent--;
    println("};");
  }

  private void printEnum(org.omg.CORBA.EnumDef def) throws 

	org.omg.CORBA.UserException {
    org.omg.CORBA.TypeCode type = def.type();
    println("enum " + type.name() + " {");
    _indent++;
    int count = type.member_count();
    for(int j = 0; j < count; j++) {
      println(type.member_name(j) + ((j == count - 1) ? "" : ","));
    }
    _indent--;
    println("};");
  }

  private void printAlias(org.omg.CORBA.AliasDef def) throws 

	org.omg.CORBA.UserException {
    org.omg.CORBA.IDLType idlType = def.original_type_def();
    String arrayBounds = "";
    while(true) {
      // This is a little strange, since the syntax of typedef'ed 
      // arrays is stupid.
      org.omg.CORBA.ArrayDef arrayDef = 

	org.omg.CORBA.ArrayDefHelper.narrow(idlType);
      if(arrayDef == null) {
	break;
      }
      arrayBounds += "[" + arrayDef.length() + "]";
      idlType = arrayDef.element_type_def();
    }
    println("typedef " + toIdl(idlType) + " " + def.name() + arrayBounds + ";");
  }

  private void printAttribute(org.omg.CORBA.AttributeDef def) throws 

	org.omg.CORBA.UserException {
    String readonly = def.mode() == org.omg.CORBA.AttributeMode.ATTR_READONLY ? 
      "readonly " : "";
    println(readonly + "attribute " + toIdl(def.type_def()) + " " + def.name() + 

	";");  
  }
  
  private void printOperation(org.omg.CORBA.OperationDef def) throws 

	org.omg.CORBA.UserException {
    String oneway = def.mode() == org.omg.CORBA.OperationMode.OP_ONEWAY ? 
      "oneway " : "";
    println(oneway + toIdl(def.result_def()) + " " + def.name() + "(");
    _indent++;
    org.omg.CORBA.ParameterDescription[] parameters = def.params();
    for(int k = 0; k < parameters.length; k++) {
      String[] mode = { "in", "out", "inout" };
      String comma = k == parameters.length - 1 ? "" : ",";
      println(mode[parameters[k].mode.value()] + " " + 

	toIdl(parameters[k].type_def) + " " + 
	      parameters[k].name + comma);
    }
    _indent--;
    org.omg.CORBA.ExceptionDef[] exceptions = def.exceptions();
    if(exceptions.length > 0) {
      println(") raises (");
      _indent++;
      for(int k = 0; k < exceptions.length; k++) {
	String comma = k == exceptions.length - 1 ? "" : ",";
	println(exceptions[k].absolute_name() + comma);
      }
      _indent--;
    }
    println(");");
  }

  private void printInterface(org.omg.CORBA.InterfaceDef idef) throws 

	org.omg.CORBA.UserException {
    String superList = "";
    {
      org.omg.CORBA.InterfaceDef[] base_interfaces = idef.base_interfaces();
      if(base_interfaces.length > 0) {
	superList += " :";
	for(int j = 0; j < base_interfaces.length; j++) {
	  String comma = j == base_interfaces.length - 1 ? "" : ",";
	  superList += " " + base_interfaces[j].absolute_name() + comma;
	}
      }
    }
    println("interface " + idef.name() + superList + " {");
    _indent++;
    print(idef);
    _indent--;
    println("};");
  }

  private void printModule(org.omg.CORBA.ModuleDef def) throws 

	org.omg.CORBA.UserException {
    println("module " + def.name() + " {");
    _indent++;
    print(def);
    _indent--;
    println("};");
  }
}