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SCEA questions 2

Question 18

A Fortune 500 company wishes to add new functionality to their existing sales system and has contracted you as the lead architect for the project. The legacy system has been written in C++. They wish to keep this system running and may switch over to a full Java solution later, depending on the performance of the new functionality. So how will connect to this legacy system?
a) Wrap the application using JNI and make it accessible using RMI.	b) Rewrite the C++ code in Java. This shouldn’t be too hard because it’s converting from one object-orientated language to another.
c) Use a screen scraper.	d) Use CORBA to talk to the C program then get the CORBA to talk to the RMI server.

Question 19

In a Catalog Enterprise Bean, used in an online sports shopping site, you have code that will be executed when ejbPassivate() and ejbActivate() methods are called. Since the code performs

basic house keeping tasks, you need to know when these methods would get executed.Which of the following statements are therefore true?

a. ejbPassivate() is called prior to passivation.
b. ejbPassivate() is called immediately after passivation.
c. ejbActivate() is called prior to activation.
d. ejbActivate() is called immediately after activation.

Question 20

You are working for a company with a worldwide presence; its offices are spread across many countries and over many computer networks. The company has set up Virtual private networks to increase security. What are

Virtual Private Networks (VPNs) and where are they created?

a)A network created between two other networks (these are not located in the same place, geographically). Encryption and Authentication are used in the VPN. Normally the VPN is a network on top of an

untrusted network (like the Internet).

b) The area between two firewalls. You let traffic from the Internet

into this area (through the first firewall) but not through the second firewall (to your secure network).

c) The secure (inner) network as described in choice B.

d) A network created between two other networks (these are not located in the same place, geographically.) Encryption and Authentication are NOT used in the VPN. Normally the VPN is a

network on top of a trusted network (like the Internet).

Question 21

You are the lead architect for a project that requires interfacing with existing CORBA systems. You are planning to use Java IDL to integrate with these other systems. Which of the following statements about Java IDL are true?

a. Allows Java to use CORBA.
b. Should be used when most of your new Java applications will be entirely Java based.
c. Should be used if you have already been using CORBA for a while and wish to carry on with some CORBA systems.
d. Java IDL has nothing to do with CORBA. To communicate with CORBA you will need to use JNI (Java native interface) and J2C (Java 2 CORBA).
e. Same as D except you won’t need to use JNI.
f. Should be used when servicing messaging requests from CORBA clients.

a) A & E

b) B, C, & E

c) A, E & F

d) A & C

Question 22

You are creating a web application for an online product ordering system. You have decided to use connection pooling to reduce load on the databases. Since you have many databases, you want to create one pool instance of the ConnectionPool class for each database. Depending on what is requested, you may have to connect to a variable number of databases. What pattern should you use?
a) Abstract factory	b) Factory Method
c) Builder	d) Prototype
e) Singleton

Question 23

When should you use Java IDL and when should you use RMI-IIOP? a. You should use Java IDL when using Enterprise Java Beans. b. You should use RMI-IIOP when using Enterprise Java Beans. c. You HAVE to use RMI-IIOP when using Enterprise Java Beans. d. Java IDL can be used even if the remote interfaces were originally defined as RMI interfaces. e. RMI-IIOP can be used with CORBA only if the remote interfaces were originally defined as RMI interfaces. f. RMI-IIOP can be used with CORBA even if not all of the remote interfaces were originally defined as RMI interfaces. g. It comes down to programmer preference as both can be used in all situations.
a) B, E & G	b) A, F & G
c) B & F	d) B & E
e) D, E & F

Question 24

You’ve designed an application that allows customers to buy chapters of e-books. Due to the enormous success of the project, there are plans to launch this application worldwide. In the process of converting the application to be suitable for worldwide use which of the following would you find yourself using frequently? a. Defines create (), find (), remove (Object) methods. b. Defines signatures of EJB’s business methods. c. Defines the persistence of the bean, e.g. how to persist etc. d. Defines all methods that the client can call on the EJB. e. You don’t need a Remote interface for an EJB. An EJB consists of a Home interface and an EJBObject interface.
a) B, D	b) A & C
c) B & E	d) B & D
e) A, C & E

Question 25

You’ve designed an application that allows customers to buy chapters of e-books. Due to the success of the project this will be launched as a worldwide application. In the process of converting this application to be suitable for worldwide use which of the following will you use?
a) Java already runs with 16 bit characters as standard. So you don’t need to use any particular classes to change text. All primitives can be used.	b) java.text package
c) java.lang.Integer Class	d) java.lang.Number Class
e) java.international package	f) java.Unicode package

Question 26

You have a distributed system that is not made up entirely of Java objects (some of them are CORBA.) What J2EE technology should you use in this situation?
a) RMI-JRMP	b) CORBA
c) Rewrite the objects so the system in entirely Java based	d) RMI-IIOP

Question 27

As part of a new application you are building, you need to connect to a database. Note that this database is used to store third party product details and it does not belong to your company. You do not have any access to the server where the database is installed and only have read permissions for the database. Further, you cannot change the ODBC driver that is currently installed. How do you connect to this database?
a) CORBA	b) JMS-JNI
c) JDBC-ODBC	d) Bridge
e) JDBC

Question 28

You have had enough of all the UML tools in the market, as they are all very cumbersome to use. Hence you have decided to design your own UML tool. However, during design, you realize that certain parts will be really complicated. For example, you have a Diagram object that is made up of lots of other objects. This diagram object can be used for creating a variety of other diagrams including class and sequence diagrams. When you create it you only want to specify its type and content. What design pattern should you use here? In the Tips section, the tiers under N-Tier architecture need to be indented. Currently they are at the same indentation as the parent.
a) Publish/Subscribe	b) Point-to-Point
c) Topic Messaging	d) Instant Messaging
e) You wouldn’t use messaging

Question 29

You have had enough with all the UML tools on the market as none do exactly what you want them to. So you’ve decided to design your own. However when designing it you realize that certain parts will be really complicated for example you have a Diagram object that is made up of lots of other objects. This diagram object can be used for a variety of different diagrams including class and sequence diagrams. When you create it you only want to specify its type and content. What pattern should you use?
a) Abstract Factory	b) Factory Method
c) Builder	d) Decorator