some unsure questions on phase 1

[Jacky Doner]

hi,all
I have been preparing the exam of SCEA PHASE I,and I have some question listed as follows.I'm not sure the correct answer to each question,I hope
someone can give me some instructions on them.Thanks a lot.

1. Which statement describes a normal default security restriction applied to classes loaded from untrusted sourced by Java-enabled browsers? (Choose one)
A. Untrusted classes cannot load trusted classes.
B. Untrusted classes cannot create server sockets.
C. Untrusted classes cannot load untrusted classes.
D. Untrusted classes cannot initiate any network connections.
E. Untrusted classes cannot display windows outside of the browser.


2. A steel industry association has hired you, a Megasoft network consultant, to create a B2B architecture for the steel industry.What does this mean? (Choose one)
A. You have to create a portal to allow consumers to order steel products.
B. You have to create a portal to exchange news and information about the steel industry.
C. You have to create an infrastructure to allow the exchange of product catalog information between steel companies.
D. You have to create an architecture to allow the exchange of order information between steel companies order systems.

3. What is a benefit of bean pooling in an EJB container? (Choose one)
A. It improves the portability between databases.
B. It reduces the number of database connections.
C. It provides better support to object-oriented databases.
D. It reduces the memory allocation and garbage-collection cycles.


4. Which items provides tools to allow the formatting of currency and date information according to local conventions? (Choose one)
A. java.text package
B. java.util.Locale class
C. java.lang.String class
D. Pluggable look and feel in Swing
E. Readers and Writers in the java.io package


5. Which statement describes a normal default security restriction applied to untrusted classes by a Java-enabled browser? (Choose one)
A. Untrusted classes cannot read data from arbitrary files.
B. Untrusted classes cannot initiate any network connections.
C. Untrusted classes cannot write sensitive data to the screen.
D. Untrusted classes cannot make unrestricted use of CPU power.
E. Untrusted classes cannot read sensitive data from the keyboard.


6. Megasoft Grapes, a vineyard, is developing an online ordering system to sell wine online. Because of local sales restrictions, the vineyard is working with local wine stored to deliver wine to the customers. The requirements for the system are:
? Customers keep their choices in a "wine list"
? Requests are fulfilled as the vintage become available.
? Local wine shops track wines that have been ordered by customers in their area.
? All order and product data is stored in an RDBMS.
? Both customers and local wine shops use the Internet to access the system.
? The system must be scalable and secure.
Which two interactions must be secure? (Choose two)
A. Customers adding wine to their wine list.
B. The application server generating a sales report.
C. The application server updating the order information into the DB.
D. The local wine stop checking what wines have been ordered locally.


7. What are three benefits of design patterns? (Choose three)
A. They act as a learning aid.
B. They provide standard code libraries.
C. They provide a common design vocabulary.
D. They standardize the way designs are developed.
E. They describe an object-oriented development process.


8. Which two statements about JMS are true? (Choose two)
A. JMS supports Publish/Subscribe.
B. JMS uses JNDI to find the destination.
C. JMS enhances access to email services.
D. JMS uses JMX to create a connectionFactory.



9. Which three are aspects of an application are most likely to be determined at runtime based on the user's declared nationality of locale? (Choose three)
A. Currency formats.
B. Network protocols.
C. Textual output messages.
D. Calculations and/or algorithms.
E. Server host names and/or addresses


10. These are the requirements for your new system:
? All current business logic is in the form of database-stored procedures.
? All current and new business logic is to be migrated to EJB.
? The system is an online, Web-based system. The UI is HTML-based.
? There are three EJBs: Customer, Order, and Account. There is one Java object, ShoppingList,which holds the current list of ordered items.
? Only account and order data are stored in the database.
? The Customer EJB maintains a reference to the ShoppingList.
Which three architectural decisions adhere to the requirements? (Choose three)
A. Make Order and Account an entity EJB.
B. Make Customer a stateful-session EJB.
C. Make Customer a stateless-session EJB.
D. Make Customer an entity EJB and put business logic in it.
E. Make Customer a session EJB and put business logic in it.
F. Use the Container Managed Persistence policy for the Customer session EJB.


11. Megasoft's application uses several entity beans accessing each other for information. The company found the architecture to be low in flexibility because they embedded entity relationships in the entity beans.
What is an alternative solution? (Choose one)
A. Use a stateful session bean as a Mediator to the entity beans.
B. Use a stateful session bean as a Fa?ade to other session beans.
C. Use a servlet to give clients direct access to data in a database table.
D. Use a stateless session bean to access the database directly instead of using entity beans.

[E. Messing]

1 : E
2 : D
3 : D
4 : B - a little tricky..
5 : A
6 : B , C
7: C , D , A/E - cant decide for sure - what do you think ?
8 : A,B - not 100% sure about B. statement is a little clumsy - but i think they ment you can use JNDI to locate JMS destination.
9 :A, C, D
10 : A, B , F - but Im not really sure about B + F. what do you think ?
11 : B.

If you need explanasions for any of the choices i made - point to which and i'll ellaborate

[Jacky Doner]

hi Messing,

First I own thanks to your reply,and I hold some different opinions on question 6,7,10,11.I explain my opinions each as follows.
6 question:
I think D is correct answer,as far as B is concerned,it says a sales report generating on the app server.Since the report generated by some app class using fetching data from db,why it should be secured.Let's turn to answer D,it says the local wine shop checking what wines have been ordered locally,if no security is used,who can sure the order lists are modified or not,who can sure the order lists are just the custom have ordered?

7.question:
We all are sure B is wrong,the unsure answer is which one of other is also wrong.I don't think C is correct answer,for it says they provide a common design vocabulary,just a common design vocabulary!The question ask for the benefits we can obtain from using design pattern.Do you think a vocabulary can benefits us a lot?

10.question:

You say answer A, B , F are correct,but at least F must be wrong,for it says use cmp for the Customer session EJB,It is impossible to use cmp for session bean,the pesistence just use for entity bean. A is obvious true,B maybe true but I'm not sure,and the other correct answer,I think,maybe E,but the question says "The Customer EJB maintains a reference to the ShoppingList" . What do you think of that?
11.question:

I don't think B is correct answer,instead I think A is,for the question tell us "uses several entity beans accessing each other ,the architecture to be low in flexibility because they embedded entity relationships in the entity beans." The key to the question is how to improve flexibility between these coupling entity beans,if we use Mediator,we can use one object act as central control role to prevent from such coupling,and need exchange information each other between them. you say?
Hope for any reply.

[Omar Ocampo]

Hey Guys,
Here are my answers
1) E
2) D
3) D
4) B
5) A
6) C, D (This is one is tough... I'm really not sure, but my logic is as follows: since is internet based, you will need the store owner logging in to check orders, and the application logged in to the DB to perform CRUD operations.... any other guesses)
7) A, C (definitely C !! ... trust me )
8) A, B
9) A, C, D
10) A, B, E
11) A (in order to remove the entity embedded relationship, but yet have relationship )

I welcome any comments on any of these answers.... Perhaps by debating them we can all learn what the correct or logical answers are.
Regards,
Omar
====
PS: Jacky, thank you for posting such challenging questions !!

[E. Messing]

Sure , glad to get some more practice before the exam...
The questions :
6 :
About b - As i understood the question, the secure part is securing the genrating of the report - so no one un authorised could see it...
About d : At first i didnt understood why to secure the list of wines that have been ordered.. This is becuase i thought - if they get the wrong list, they would just oreder the wrong wines- no "money" harm done.
BUT - now as i look at the question, it says :"local wine stored to deliver" . So if the local store is only delivering to the customer, and the customer payed on line (it doesnt really say where he paid - i am just making an assamption) so a "hacker" customer could pay for only 2 bottles, and fake a list of 20... So :
D is more secure needy then B, So I am going with your call.
7 :
About c : take a look here- http://citeseer.nj.nec.com/context/1097131/271761
look for the word vocabulary...
10 :
About f : sorry - my mistake - i thought it said "CMT"
So - now when E is wrong, and we know Customer doesnt need to be Entity (it says it doesnt need to be pasivated), but it does hold a reference to a state-related object (the ShoppingList) so the correct answers as i see it are A, B, E. So we agree.
11:
I am used to get session bean act as a facade to entity. Part of facading the entity is madiate calls to 1 or more entities, so - we can argue about that - I can certainly say that the question is tricky.
Look at page 27 here http://www.simongbrown.com/presentations/j2ee-business-patterns.pdf
So - we can say we are both right
Hopes it helps
[ January 31, 2004: Message edited by: E. Messing ]

[Jacky Doner]

Thanks for your valuable replies.As for question 7,can you give the three
whole answers to us.while,I have some other unsure questions,hope for any
replies and any ideas again.The questions list as follows:
1. The following statement is true about which type of EJB?
"All bean instances are equivalent when they are not involved in serving a client-invoked method". (Choose one)
A. Stateful session bean
B. Stateless session bean
C. Entity bean with bean-managed persistence
D. Entity bean with container-managed persistence
2. Which two statements are true about management of an EJB's resources? (Choose two)
A. The reference to the remote object is obtained through JNDI to improve maintainability and flexibility.
B. The reference to home object is obtained through JNDI to improve maintainability and flexibility.
C. The EJB container can manage the instance's access to its resources because the home object acts as a proxy.
D. The EJB container can manage the instance's access to its resourced because the remote object acts as a proxy.
3. Which statement about an EJB container's lifecycle management of session beans is true? (Choose one)
A. The client is responsible for the object identity for session beans.
B. The client can passivate a session bean after a specified timeout period.
C. The container can passivate a stateful session bean to free limited resources.
D. The container can passivate a stateless session bean to free limited resources.
4. Which two statements about stateless session beans are true? (Choose two)
A. They provide a generic service.
B. They maintain a cached state on behalf of a specific client.
C. They maintain a conversational state on behalf of several clients.
D. They may provide high performance by being available for multiple clients.
5. What are two clear advantages to using message services in an application? (Choose two)
A. Provides scalability
B. Provides secure communication services.
C. Allows loose coupling between components.
D. Allows clients and servers to communicate directly.
6. A department of Megasoft Inc uses entity beans with bean-managed persistence to access an RDBMS.The entity beans contain the code to access the database directory. Megasoft decides that other departments can reuse the business logic to access their database, which include an OODBMS and a different type of RDBMS.
Which statement best describes how the Megasoft can integrate their departmental business logic to access the various databases, and to ensure that the entity bean code is easy to read? (Choose one)
A. Use session beans to access an entity bean through a data access object.
B. Move the data-access code out of the entity beans into a data-access object.
C. Distribute the data-access code among several entity beans to access different databases.
D. Use session beans to access several entity beans that represents the data in all three databases.
7. You have determined that the interactions between objects in a system are complex, and that the objects are tightly coupled. Furthermore, additional functionality would require the modification of many objects in the system.
Which pattern will solve this problem? (Choose one)
A. Fa�ade
B. Mediator
C. Template
D. Prototype
E. Command
8. The requirements for an online shopping application are:
� It must support millions of customers.
� The invocation must be transactional.
� The shopping cart must be persistent.
Which technology is required to support these requirements? (Choose one)
A. JNI
B. JMS
C. EJB
D. JMX
9. Which two services does EJB provide? (Choose two)
A. HTML generation
B. Transaction services
C. Lifecycle management
D. Remote-method invocation

[E. Messing]

So I think 7 is what i wrote in the first place - C , D , A
Second round :
1 : B
2: B , D
3 : C
4 : A , D
5 : C, A - not sure about A - what do you think ?
6 : This one is tricky. What they actually want is "reuse the business logic". So - they don't want to copy the hall entity beans ( with the logic) , and use different entity bean just because the persistent method is different.
A - is a wrong statement.
B - is a good practice - but irrelevant to this specific issue - the DAO will have the SQL written in it - and they don't state that the Bean will use different DAO for each DB - which would have make this answer a possible right one.
C - this looks like the best scenario : get 1 main entity bean with the business logic, and have all of its data from relationship beans. the specific relationship beans will be decided upon the department - hence different DB, and different persistence method. I just hope they meant what I meant...
D - This option is doable - just that the Business logic is copied between the different entity beans. So the session bean act as a FACADE , and call the right entity beans - by the needed department (kinda like "strategy" pattern). Again - If this is what they mean - this is copying of the business logic , and they wanted to reuse it.
So its C... I think
7 : B.
8 : C
9 : B, C

[Omar Ocampo]

Hi all,
I didn't realize that question 7 (from the first set of questions) required 3 answers. My answer for 7 is A, C, D
I agree with Messing.
Here are my answers to the 2nd set of questions: (By the way, these are a lot easier than the first set)
1) B
2) B, D
3) C
4) A, D
5) A, C
6) B --- You guys should really understand this one. I gurantee you this type of question (if not the same one) will be on the actual exam. DAO are used to encapsulate schemas and type of databases.
7) B
8) C
9) B, D --- Messing, note that it say the EJB not the EJB container... I initially chose C, but then realize that is not talking about the container.

Jacky, again thank you for posting these questions. Btw, where do you get these questions from ? .... just curious.

Omar
====

[E. Messing]

Hi Omar.
Well - I will have to disagree on 6 and 9.
6 - see my comments about option B.
9 - "Remote Method Invocation" (RMI) is not a service... Its a method of distributed communication/operation..
I believe your notation about EJB and EJB container is too sophisticated for the question authors.. Im quite sure they meant EJB and its container specification.
Again - I can be wrong...

[Jacky Doner]

hi,friends:
You give me almost similar answers to the second round questions.If you
compare the answers to each other you gives me,you will find there are 2 questions that answers is diiferent.One question is 6,and the other is 9.
As for no.6 ,I agree with Omar,and as for 9,I agree with E. Messing .
Now,let's talk these two questions respectively.
No.6 About how to integrate business logic to access the various databases.
Notes that question tell us "Megasoft decides that other departments can reuse the business logic to access their database",that says the business logic to access other databases are identical,but as need to access various databases,we can assess the schema and vender of db are different.If we use
entity bean that encapsulate data access logic to access various databases while the logic is identical,we have to develop different entity beans to access different databases based on their different schemas yet.So if we use Dao?If we use it,we can move the whole data access logic into a shared object,other people then can reuse the shared object to access their own databse provided the data access logic is identical.
So the answer should be b,Omar's answer is correct.
No.9 about services EJB provides.
I think the qustion describes not very clearly,since it talks the service,I think the Remote-method invocation is not included ,because Remote-method invocation is a mechanics,or say funtions provided by jdk.
since the service it provide,we can unconcern concrete details ,we just
use them.So I think ,relatively speaking ,B and C are correct answers.
Hope for any debates.

[E. Messing]

Hi Jacky,
About number 6 : Let me get some issues clear - Different DB's have different connections, with different DB schemas. In the question when they say different departments, with different DBs. Each DB has its own connection pool, and its own schema.
However - they do state that the Buisness Logic(B.L) is the same for all departments.
Each entity bean has 2 kind of code lines : B.L, and DB specific. B.L code is to be reuse, and DB specific - used according to the specific DB. I think we all agree about that.
Now - How to implement this scenario ?
The B.L should stay in one place. We all agree on that too. But what about the DB specific code ?
Option B states the use of DAO. they say "object" not "objects". They say "move the data persistent code to DAO". This alone will not enable the re use of the B.L ... just nice separation..
The right solution to this problem with DAO would be to have different DAO's for each DB. each one with specific JNDI code for the specific connection, and specific SQL for the specific schema.
The entity bean - when it needs to persist something - checks the caller department, and getting the right DAO to persist (This is "Strategy" design pattern). BUT this not what the answer says.... See where I am heading ?
[ February 03, 2004: Message edited by: E. Messing ]

[Omar Ocampo]

Jacky, Messing
I think both of you are right with respect to question 9. Perhaps I did read too much into it. I now think when they say EJB they are talking about it in general, and not distinguishing between the bean and the container. As such you both righ, the answer is B and C
Jacky, I like your reasoning on question 6. You got the point of DAO.
Messing, I wont try to change my mind, that's not my intention, just
going to direct you to the definition of DAO Pattern. You will probably need to login first.
Here is a quote from there:

Solution
Use a Data Access Object to abstract and encapsulate all access to the data source. The Data Access Object manages the connection with the data source to obtain and store data.
The Data Access Object (DAO) is the primary object of this pattern. The DAO implements the access mechanism required to work with the data source. The data source could be a persistent store like an RDBMS, an external service like a B2B exchange, a repository like an LDAP database or a business service accessed via CORBA IIOP or low-level sockets. The business component that relies on the DAO object uses the simpler interface exposed by the DAO for its clients. The DAO completely hides the data source implementation details from its clients. Because the interface exposed by the DAO to clients does not change when the underlying data source implementation changes, this pattern allows the DAO to adapt to different storage schemes without affecting its clients or business components. Essentially, the DAO acts as an adapter between the component and the data source.

Anyway, overall we have done pretty good eh? We agreed on most of those questions. I think we are averaging an 80+ % score so far
Any more question Jacky ???

[Jacky Doner]

hi,friends:
I have some other questions,but it seems to be easier than them posted previouly,we might as well check them,ok?By the way,can you tell me when you
passed the phase 1,and how good score you achieved.And whether you got the
certificate or not.
1. As an architect, you are interested in the architecture characteristics of a system.
Which two are architectural characteristics? (Choose two)
A. Liability
B. Reliability
C. Inheritance
D. Performance
I think correct answer: B,D

2. A telecommunications company, Magasoft, is building an enterprise system to allow the Magasoft support staff to access customer information over an intranet. All of the customer information is stored in a legacy system and can only be accessed using a VT100 terminal session. You must create an architecture to access the legacy system.
What should you use to encapsulate access to the legacy system?
A. A JDBC connection that uses SQL to query the legacy system.
B. AN EJB entity bean that uses JMS to interact with the legacy system.
C. A distributed CORBA object that uses IIOP to interact with the legacy system.
D. An EJB session bean that uses a screen-scraping tool to interact with the legacy system.
I think correct answer: D
3. A manufacturing company, Magasoft GmBh, is building an enterprise system to allow the sales staff to place customer orders over an intranet. All orders must be placed using a legacy system running MQSeries. You must create an architecture to interact with the legacy system. How would you encapsulate interaction with that legacy system? (Choose one)
A. With an EJB session bean that uses JMS to message the legacy system.
B. With a Java class that uses a screen-scraping tool to interact with the legacy system.
C. With a distributed CORBA object that uses IIOP to interact directly with the legacy system.
D. With an EJB entity bean that uses container-managed persistence to encapsulate the legacy system.
I think correct answer:A
4. Magasoft.com, a shipping company, is building an enterprise system to track the location of packages. One part of the tracking system is a network of wireless inventory devices. The devices can only be accessed using a custom, synchronous TCP/IP protocol.How should you encapsulate interaction with the wireless inventory system? (Choose one)
A. With an EJB session bean that uses a JMS to interact with the inventory system.
B. With a Java class that uses custom Java networking to interact with the inventory system.
C. With a distributed CORBA object that uses IIOP to interact directly with the inventory system.
D. With an EJB entity bean that uses container-managed persistence to encapsulate the inventory system.
I think correct answer:B
5. What are two features of JRMP? (Choose two)
A. It is secure.
B. It is connectionless.
C. It is connection-based.
D. It is used for load balancing.
E. It is used for hypermedia requests.
F. It is used for remote-object communications.
I think correct answer:C,F
6. Which three statements about container-managed persistence are true? (Choose three)
A. A container-managed enterprise bean requires less code.
B. Container-managed persistence provides less bean control.
C. Container-managed persistence can require complex mapping techniques.
D. Container-managed persistence manages a session bean�s conversational state.
I think correct answer:A,B,C
7. What acts as a proxy to an EJB? (Choose one)
A. IDL instance
B. Home instance
C. Bean instance
D. Remote instance
I think correct answer
8. A client makes a transactionless method call to an EJB that has a transaction attribute of Required in the deployment descriptor.
Which statement is true? (Choose one)
A. The container creates a new transaction.
B. The EJB throws an EJBException since it requires transaction context.
C. The EJB throws a RemoteException since it requires a transaction context.
D. The container throws a RemoteException since the EJB must have a transaction context.
I think correct answer:A

9. Your client is a bank that wants to allow its customers to access their bank accounts over the Internet.
Given the following requirements, which protocol communicates with the Web browser?
� Confidential information must be protected.
� Customers will access their accounts using only a simple Web browser with no extension. (Choose one)
A. IIOP
B. HTTP
C. SNMP
D. HTTPS
I think correct answer

10. Which pattern provides a means to access the elements on an aggregate object sequentially without exposing the underlying structure? (Choose one)
A. Proxy
B. Iterator
C. Strategy
D. Observer
E. Singleton
I think correct answer:B

11. What are two benefits of the Fa�ade pattern? (Choose two)
A. It hides complex subsystems from clients.
B. It allows objects to masquerade as different objects.
C. It decouples the object interface from the implementation.
D. It encourages weak coupling between the client and the subsystem.
I think correct answer:A,D
12. Which design pattern is represented by the EJB Home interface? (Choose one)
A. Proxy
B. Visitor
C. Fa�ade
D. Abstract Factory
I think correct answer: D

13. QUESTION NO: 120
You are developing an HR application with the following requirements:
� Users access the systems over an intranet, using a standard Web browser.
� Organization information is stored in LDAP.
� Benefits information is stored in an RDBMS.
� Complaints are sent directly to a third-party system for compliance.
Which J2EE technology would allow the system to interact with the LDAP server? (Choose one)
A. EJB
B. JSP
C. JMS
D. JTA
E. JNDI
F. JDBC
I think correct answer:E

What's your answer ?

[E. Messing]

Hi Jacky
I am going to take the Part I in a few weeks - as soon as I will feel ready.
My answers are :
1.
B.
D.
2.
D.
3.
A.
4.
B.
5.
C.
F.
Looks familiar ?
https://coderanch.com/t/149915/java-Architect-SCEA/certification/Protocol
6.
A.
B.
C.
7.
D.
8.
A.
9.
D.
10.
B. Iterator
11.
A.
D.
12.
D. Abstract Factory
13. QUESTION NO: 120
E. JNDI

So - we think alike

[Omar Ocampo]

Jacky,
I passed SCEA part I sometime on Feb 2002. You can take a look at
my posting which details my score.
My Answers:
1) B, D
2) D
3) A
4) B
5) C, F
6) A, B, C
7) D
8) A
9) D
10) B
11) A, D
12) D
13) E
This time all of my answers match all of yours.
BTW, I have not gone for Part II of the exam because after finishing part I, I sort of lost interest... but now in the last couple of weeks that I've been visiting this site and answering Jacky questions, I have started to wonder if I should go for it.... hmmm we'll see
Omar
====

[Jacky Doner]

Hi,friends
I'm also going to take the Part I in a few weeks.After I read the message posted by Omar recently,I really don't know why Omar lost interests to
take the next phase,if you just completed Part I,there is nothing to give you by SUN.If you give it up,it's real a pity.
Here,I have two questions,let's talk about it.
1.which are true about iterator pattern?
a. allows transverse of a data collection with different order
b. allows different iterators to access a data collection simultaneously
a is correct ,Is b also correct,Why?
2. how to ensure ACID transaction for an entity EJB that access a legacy system?

a. let the container to take care transaction
b. let the entity EJB to monitor the transaction
c. set the entity bean as Container Transaction Managed

I think b must be wrong,and not sure about a and c. I know the transaction for an entity EJB must be CMP,what's the difference between a and c,they all said the container managed the transaction .

Another question lists here is posted previously,but someone tell me B
is correct answer rather than E,His reason is Untrusted classes can create only client socket,so answer is B,.As for E ,displaying windows outside of browser does not cause any big security issue ,you can always create windows outside browser.I'm quite confuse of that.The question is reposted
as follows.
3. Which statement describes a normal default security restriction applied to classes loaded from untrusted sourced by Java-enabled browsers? (Choose one)
A. Untrusted classes cannot load trusted classes.
B. Untrusted classes cannot create server sockets.
C. Untrusted classes cannot load untrusted classes.
D. Untrusted classes cannot initiate any network connections.
E. Untrusted classes cannot display windows outside of the browser.
hope for reply.

[Hu Yong Jun]

Originally posted by Jacky Doner:
hi,all
I have been preparing the exam of SCEA PHASE I,and I have some question listed as follows.I'm not sure the correct answer to each question,I hope
someone can give me some instructions on them.Thanks a lot.

1. Which statement describes a normal default security restriction applied to classes loaded from untrusted sourced by Java-enabled browsers? (Choose one)
A. Untrusted classes cannot load trusted classes.
B. Untrusted classes cannot create server sockets.
C. Untrusted classes cannot load untrusted classes.
D. Untrusted classes cannot initiate any network connections.
eeeeE. Untrusted classes cannot display windows outside of the browser.
:For A: Applet can load trusted classes such as classes in anonther jar file at the source downloading server.
:For B: Applet can connect the server from which it was downloaded, either by server socket or client socket.
:For C: Similar as A.
:For D: At least an applet can create such a connection as B said.
:For E: Applet cannot create Window.


2. A steel industry association has hired you, a Megasoft network consultant, to create a B2B architecture for the steel industry.What does this mean? (Choose one)
A. You have to create a portal to allow consumers to order steel products.
B. You have to create a portal to exchange news and information about the steel industry.
C. You have to create an infrastructure to allow the exchange of product catalog information between steel companies.
ddddD. You have to create an architecture to allow the exchange of order information between steel companies order systems.
:For D: B2B means purchase order.

3. What is a benefit of bean pooling in an EJB container? (Choose one)
A. It improves the portability between databases.
B. It reduces the number of database connections.
C. It provides better support to object-oriented databases.
ddddD. It reduces the memory allocation and garbage-collection cycles.


4. Which items provides tools to allow the formatting of currency and date information according to local conventions? (Choose one)
aaaaA. java.text package
B. java.util.Locale class
C. java.lang.String class
D. Pluggable look and feel in Swing
E. Readers and Writers in the java.io package
:For A: The question says what "tools"(the java.text package contains Format/MessageFormat/NumberFormat/DateFormat as tool), while java.util.Locale is an identity of locale


5. Which statement describes a normal default security restriction applied to untrusted classes by a Java-enabled browser? (Choose one)
aaaaA. Untrusted classes cannot read data from arbitrary files.
B. Untrusted classes cannot initiate any network connections.
C. Untrusted classes cannot write sensitive data to the screen.
D. Untrusted classes cannot make unrestricted use of CPU power.
E. Untrusted classes cannot read sensitive data from the keyboard.
:For A: for example, applet can not read local file system.

6. Megasoft Grapes, a vineyard, is developing an online ordering system to sell wine online. Because of local sales restrictions, the vineyard is working with local wine stored to deliver wine to the customers. The requirements for the system are:
? Customers keep their choices in a "wine list"
? Requests are fulfilled as the vintage become available.
? Local wine shops track wines that have been ordered by customers in their area.
? All order and product data is stored in an RDBMS.
? Both customers and local wine shops use the Internet to access the system.
? The system must be scalable and secure.
Which two interactions must be secure? (Choose two)
A. Customers adding wine to their wine list.
bbbbB. The application server generating a sales report.
ccccC. The application server updating the order information into the DB.
D. The local wine stop checking what wines have been ordered locally.
:For A: because adding to wine list occurs in the web server session, it does not need security. But if you send credential card number via network/internet, the interaction needs security.
:For B: the business report is security-sensitive.
:For C: the netwrok between application server and database server needs to be security.
:For D: i do not understand it.

7. What are three benefits of design patterns? (Choose three)
aaaaA. They act as a learning aid.
B. They provide standard code libraries.
ccccC. They provide a common design vocabulary.
ddddD. They standardize the way designs are developed.
E. They describe an object-oriented development process.

:For B: DP do not have code lib.
:For E: non-OO tech can use DP too.

8. Which two statements about JMS are true? (Choose two)
aaaaA. JMS supports Publish/Subscribe.
bbbbB. JMS uses JNDI to find the destination.
C. JMS enhances access to email services.
D. JMS uses JMX to create a connectionFactory.
:For c: jms do nothing with mail service.
:For D: jmx is about management


9. Which three are aspects of an application are most likely to be determined at runtime based on the user's declared nationality of locale? (Choose three)
aaaaA. Currency formats.
B. Network protocols.
ccccC. Textual output messages.
ddddD. Calculations and/or algorithms.
E. Server host names and/or addresses
:For B: network protocal does nothing with human interaction.
:For D: Algorithms is different among different countries.

10. These are the requirements for your new system:
? All current business logic is in the form of database-stored procedures.
? All current and new business logic is to be migrated to EJB.
? The system is an online, Web-based system. The UI is HTML-based.
? There are three EJBs: Customer, Order, and Account. There is one Java object, ShoppingList,which holds the current list of ordered items.
? Only account and order data are stored in the database.
? The Customer EJB maintains a reference to the ShoppingList.
Which three architectural decisions adhere to the requirements? (Choose three)
aaaaA. Make Order and Account an entity EJB.
bbbbB. Make Customer a stateful-session EJB.
C. Make Customer a stateless-session EJB.
D. Make Customer an entity EJB and put business logic in it.
eeeeE. Make Customer a session EJB and put business logic in it.
F. Use the Container Managed Persistence policy for the Customer session EJB.
:For A: "Only account and order data are stored in the database"
:For B: "The Customer EJB maintains a reference to the ShoppingList", something like shoping cart.
:For E: "These are the requirements for your ***new*** system" and "All current and new business logic is to be migrated to EJB"
11. Megasoft's application uses several entity beans accessing each other for information. The company found the architecture to be low in flexibility because they embedded entity relationships in the entity beans.
What is an alternative solution? (Choose one)
aaaaA. Use a stateful session bean as a Mediator to the entity beans.
B. Use a stateful session bean as a Fa?ade to other session beans.
C. Use a servlet to give clients direct access to data in a database table.
D. Use a stateless session bean to access the database directly instead of using entity beans.
:For A: Omar Ocampo said "in order to remove the entity embedded relationship, but yet have relationship "

[Hu Yong Jun]

Originally posted by Jacky Doner:
Thanks for your valuable replies.As for question 7,can you give the three
whole answers to us.while,I have some other unsure questions,hope for any
replies and any ideas again.The questions list as follows:
1. The following statement is true about which type of EJB?
"All bean instances are equivalent when they are not involved in serving a client-invoked method". (Choose one)
A. Stateful session bean
B. Stateless session bean
C. Entity bean with bean-managed persistence
D. Entity bean with container-managed persistence
(b)
2. Which two statements are true about management of an EJB's resources? (Choose two)
A. The reference to the remote object is obtained through JNDI to improve maintainability and flexibility.
B. The reference to home object is obtained through JNDI to improve maintainability and flexibility.
C. The EJB container can manage the instance's access to its resources because the home object acts as a proxy.
D. The EJB container can manage the instance's access to its resourced because the remote object acts as a proxy.
(b d)
Home object is not proxy of bean instance
3. Which statement about an EJB container's lifecycle management of session beans is true? (Choose one)
A. The client is responsible for the object identity for session beans.
B. The client can passivate a session bean after a specified timeout period.
C. The container can passivate a stateful session bean to free limited resources.
D. The container can passivate a stateless session bean to free limited resources.
(c)
session bean has no id.
session bean instance will be removed when timeout.
stateless bean has no passivation/activation.
4. Which two statements about stateless session beans are true? (Choose two)
A. They provide a generic service.
B. They maintain a cached state on behalf of a specific client.
C. They maintain a conversational state on behalf of several clients.
D. They may provide high performance by being available for multiple clients.
(a d)
generic service such as transaction,security,naming.
5. What are two clear advantages to using message services in an application? (Choose two)
A. Provides scalability
B. Provides secure communication services.
C. Allows loose coupling between components.
D. Allows clients and servers to communicate directly.
(a c)
6. A department of Megasoft Inc uses entity beans with bean-managed persistence to access an RDBMS.The entity beans contain the code to access the database directory. Megasoft decides that other departments can reuse the business logic to access their database, which include an OODBMS and a different type of RDBMS.
Which statement best describes how the Megasoft can integrate their departmental business logic to access the various databases, and to ensure that the entity bean code is easy to read? (Choose one)
A. Use session beans to access an entity bean through a data access object.
B. Move the data-access code out of the entity beans into a data-access object.
C. Distribute the data-access code among several entity beans to access different databases.
D. Use session beans to access several entity beans that represents the data in all three databases.
(b)
DAO pattern.
DAO makes ejb independent of db/resource adapter
7. You have determined that the interactions between objects in a system are complex, and that the objects are tightly coupled. Furthermore, additional functionality would require the modification of many objects in the system.
Which pattern will solve this problem? (Choose one)
A. Fa?ade
B. Mediator
C. Template
D. Prototype
E. Command
(b)
8. The requirements for an online shopping application are:
? It must support millions of customers.
? The invocation must be transactional.
? The shopping cart must be persistent.
Which technology is required to support these requirements? (Choose one)
A. JNI
B. JMS
C. EJB
D. JMX
(c)
9. Which two services does EJB provide? (Choose two)
A. HTML generation
B. Transaction services
C. Lifecycle management
D. Remote-method invocation
(b c)
rmi is protocal

[E. Messing]

Jacky - about question 3 :
This is from "Cade SCEA study Guide " :
"
Downloaded classes have restricted access to the I/O system so, for example, they are neither permitted to display a top level window with no warning, nor to grab keyboard or mouse events from other windows.
"
So- applet can only display a window the belongs to the applet - and has a warning on it. To allow the applet to open a Top Level window is a security hole - because it enables the opening of windows to the user that can ask for its user/password - disguising as an, for example, ActiveDirectory window.. See the potential ?
About server sockets- I think they meant sockets to the server / making their server opening sockets to them - which is doable...
[ February 05, 2004: Message edited by: E. Messing ]

[Omar Ocampo]

Hey All,
Here are my answers to the new set of questions:
1) A, B (B is correct because an iterator keeps trak of its own traversal state. Therefore you can have more than one traversal in progess at once. Does that make sense? now take a look at Gamma's Design Patterns book on page 260 for the explanation of A and B)
2) You are right Jacky, the answers don't make any sense. In fact none of the answers ensure ACID transaction to a legacy system. In order for the distributed transaction to be ensure, you need a Transaction manager that supports 2 phase commit, that is, that implements the X/A Interface.
3) E ( You are right Messing. Jacky look at Messing explanation for why E is the correct answer. As for B, untrusted classes can create sockets to the server where they were downloaded from. Your friend is wrong, you will not be able to create and bind to a socket on the Client machine... Try it)

Regads,
Omar
====

[Joseph Zhou]

I think the correct answer for Q10 is ACE
10. These are the requirements for your new system:
? All current business logic is in the form of database-stored procedures.
? All current and new business logic is to be migrated to EJB.
? The system is an online, Web-based system. The UI is HTML-based.
? There are three EJBs: Customer, Order, and Account. There is one Java object, ShoppingList,which holds the current list of ordered items.
? Only account and order data are stored in the database.
? The Customer EJB maintains a reference to the ShoppingList.
Which three architectural decisions adhere to the requirements? (Choose three)
A. Make Order and Account an entity EJB.
B. Make Customer a stateful-session EJB.
C. Make Customer a stateless-session EJB.
D. Make Customer an entity EJB and put business logic in it.
E. Make Customer a session EJB and put business logic in it.
F. Use the Container Managed Persistence policy for the Customer session EJB.
Because Customer EJB maintains a reference to the ShoppingList, it keeps the state of the shopping list, stateful session bean is not required, any thoughts?

[E. Messing]

Yanqu - Because it needs to maintain a reference to a statefull object - it needs to be statfull as well.
Think of the customer class - it has a member : ShoppingList list;
When initialaized - it get the refference to the customer specific ShoppingList. And it needs this specific reference all over its different methods. So its kinda have state - the reference to the shopping list.
Plus - it would probably save other customer details as well - name, id etc - to also use all over its methods.

[Joseph Zhou]

Thanks E. Messing, but I still don't think so.
When the reference to the Customer is there, all state is there, it across all its methods, as well as any customer specific info.
If we don't care the feature like "sleep to storage" etc. I think that could be the common way we implement shopping cart.

[Jacky Doner]

hi,all friends
I'm so surprised that more and more friends engaged in the such a warm discuss.And on the other hand,I got much more puzzled on the following questions,for we can't come to agreement on them,and everyone seems to give a reasonable explantion on them.So can we reconfirm them?
1. Which items provides tools to allow the formatting of currency and date information according to local conventions? (Choose one)
A. java.text package
B. java.util.Locale class
C. java.lang.String class
D. Pluggable look and feel in Swing
E. Readers and Writers in the java.io package
I'm more convinced on answer B,for the question tell us "according to local conventions".
2. Megasoft Grapes, a vineyard, is developing an online ordering system to sell wine online. Because of local sales restrictions, the vineyard is working with local wine stored to deliver wine to the customers. The requirements for the system are:
? Customers keep their choices in a "wine list"
? Requests are fulfilled as the vintage become available.
? Local wine shops track wines that have been ordered by customers in their area.
? All order and product data is stored in an RDBMS.
? Both customers and local wine shops use the Internet to access the system.
? The system must be scalable and secure.
Which two interactions must be secure? (Choose two)
A. Customers adding wine to their wine list.
B. The application server generating a sales report.
C. The application server updating the order information into the DB.
D. The local wine stop checking what wines have been ordered locally.
I'm more convinced on answer c,d.By the way,the word stop in answer d
I think it is misspelled,the word should be changed to shop.
3.which are true about iterator pattern?
a. allows transverse of a data collection with different order
b. allows different iterators to access a data collection simultaneously
A is obviously correct.As for B,I agree the opinion that more than one iterator can travel the collection,but can them travel the collection simultaneously?
4.How to ensure ACID transaction for an entity EJB that access a legacy system?
a. let the container to take care transaction
b. let the entity EJB to monitor the transaction
c. set the entity bean as Container Transaction Managed
If entity bean evolved in transaction ,it should be use CMT.I really don't know if we use the Transaction manager that supports 2 phase commit into this scenery,whether the operation we can call is BMT,or throughly it is no relation to EJB container(i.e. the transaction is not directed by container).If it is no relation to EJB container,then all answer is wrong.But what on earth is the fact?
Hope for any reply ...

[Hu Yong Jun]

Originally posted by Yanqu Zhou:
I think the correct answer for Q10 is ACE
10. These are the requirements for your new system:
? All current business logic is in the form of database-stored procedures.
? All current and new business logic is to be migrated to EJB.
? The system is an online, Web-based system. The UI is HTML-based.
? There are three EJBs: Customer, Order, and Account. There is one Java object, ShoppingList,which holds the current list of ordered items.
? Only account and order data are stored in the database.
? The Customer EJB maintains a reference to the ShoppingList.
Which three architectural decisions adhere to the requirements? (Choose three)
A. Make Order and Account an entity EJB.
B. Make Customer a stateful-session EJB.
C. Make Customer a stateless-session EJB.
D. Make Customer an entity EJB and put business logic in it.
E. Make Customer a session EJB and put business logic in it.
F. Use the Container Managed Persistence policy for the Customer session EJB.
Because Customer EJB maintains a reference to the ShoppingList, it keeps the state of the shopping list, stateful session bean is not required, any thoughts?

But which shopping list?
So you need a stateful session bean referencing a shopping list object.

[Joseph Zhou]

2. Megasoft Grapes, a vineyard, is developing an online ordering system to sell wine online. Because of local sales restrictions, the vineyard is working with local wine stored to deliver wine to the customers. The requirements for the system are:
? Customers keep their choices in a "wine list"
? Requests are fulfilled as the vintage become available.
? Local wine shops track wines that have been ordered by customers in their area.
? All order and product data is stored in an RDBMS.
? Both customers and local wine shops use the Internet to access the system.
? The system must be scalable and secure.
Which two interactions must be secure? (Choose two)
A. Customers adding wine to their wine list.
B. The application server generating a sales report.
C. The application server updating the order information into the DB.
D. The local wine stop checking what wines have been ordered locally.
B and D are from remote and with business info, so they must be secure.
usually application server and DB co-located, C is not necessary.

[Jacky Doner]

hi,friends
Please focus the recent messages I posted,I hope for the full replies from you.