Home > Articles

Objectives and Deliverables

This chapter is from the book

Terms you'll need to understand:

  • Assignment requirements

  • Graphical user interface (GUI)

  • Javadoc

Techniques you'll need to master:

  • Making software design decisions by analyzing requirements

  • Providing a complete application as one JAR file, following the detailed instructions provided

In this chapter, you review the objectives and deliverables for the Sun Certified Java Developer (SCJD) certification. Because this certification has an assignment (the Sun Certified Enterprise Java Architect exam also has an assignment), it differs from most certification exams. In fact, the moderately difficult assignment, which can take months to complete, separates it from most industry certifications, which are usually proctored exams.

Objectives

The following are the main objectives for this certification:

  • Write an application program with Java. The application requires the following:

    • A graphical user interface (GUI) demonstrating good Human/Computer Interaction (HCI) principles of design.

    • A network connection, using RMI or sockets, to connect to an information server.

    • A network server that connects to the database; its skeleton is included in the download.

    • A database created by extending the functionality of the skeleton code, which comes with limited documentation.

  • In the DESIGN_CHOICES.TXT document and essay exam, you are asked to list some of the major choices you made for your design and implementation.

  • In the DESIGN_CHOICES.TXT document and essay exam, you are asked to list some of the main advantages and disadvantages of each of your choices.

  • In the DESIGN_CHOICES.TXT document and essay exam, you are asked to justify your choices by comparing your design and implementation objectives, including the advantages and disadvantages of each.

TIP

The database does not use Java Database Connectivity (JDBC). Rather, it is a simple file reader/writer supplied by Sun. Also, Sun supplies the data file, called database.bin. Sun wants you to create a database from these two elements.

The challenge is to convince the Sun evaluator that you understand how to build a client/server application that meets a given set of requirements. Along the way, this certification helps you understand and model a business need. I hope, however, that this book provides a solid guide to identifying and refining Sun's instructions and requirements. Although these requirements are written with or without formal language for requirements, they are good enough to see what you can do.

A better way to certify developers is to define a project by using standard documentation. For example, the SCJD certification's quality and utility would be improved if Sun used a three-part process. First, Sun would provide a project charter with a few owner interviews, the software objectives, and the overall purpose. Using this information, you would write a formal Software Requirements Specification (SRS; IEEE standard 830-1993, "Recommended Practice for Software Requirements Specifications") for that project. You would then exchange your SRS for Sun's by uploading your SRS and downloading Sun's SRS. Second, you would write a design document meeting those requirements, following the IEEE standard 1016.1-1993, "Guide to Software Design Descriptions." Third, you would exchange your design document for Sun's (which is what your design document is graded against) and write code to that document. This process is better and closer to reality. More important, it removes the ambiguity every candidate finds in the current instructions bundled in the assignment package.

Some would argue that my suggested certification process would be too difficult to standardize. Perhaps the reverse is true: Because the current assignment instructions are in nonstandard form, using industry-standard documentation and the software development life cycle would improve consistency and quality, representing a more reliable measure of a developer's skill.

GUI Design

One of the key ingredients for earning top marks is to design a clean interface for the user. As the human interface designer, you need to choose the interface components and lay them out proportionately. Java makes the nuts-and-bolts aspect of this exercise straightforward. Chapters 13, "The GUI," 14, "The Swing Components and Event Handling," and 15, "The JTable Component," discuss this topic at length. For now, please be aware that although there are many ways to build the screens for your assignment, Sun will surely appreciate your project following its recommended design guidelines.

The Java look and feel provides a distinctive platform-independent appearance and standard behavior, which is why one of the requirements specifies that you use Swing components, not Abstract Windowing Toolkit (AWT) components. Using the single look and feel that Swing provides helps ensure that what you see is what the evaluator will see. Sun wants to know whether you can take advantage of built-in Swing components. For example, you must use the JTable component. It is a helpful grid component, and feeding data into it is easy. However, the event model takes a little getting used to.

Database

The heart of the project is the database. Sun provides the skeleton pieces, which you must use to build your database. It is not as big a task as it sounds. The base classes Sun provides are already good enough. You just have to decide how much to modify the main piece (Data.java) and what you need to add in any additional classes. One common mistake is to overengineer the solution. My database met all the requirements and seemed to be a clean design, yet I added only two classes and didn't modify any Sun-supplied code. I've read many forum posts from developers who were looking for help on their code, but had clearly gone too far. What they were doing was unnecessary, or worse, obscured the real functionality they should have built.

One major ingredient of the database design is the locking mechanism. Chapter 7, "Databases and Atomicity," discusses the details of a good lock manager, the better way to go for this project. One hidden requirement is that only the client who locks a row can unlock it. This means there has to be a way to track clients within the locking mechanism. I've seen some clever ways to tackle it and some truly bizarre approaches that would surely lose points. A tricky part is what to do if the client locks a record and then dies. One elegant way to handle that situation is to let the system worry about it rather than invent some polling or timed checker design. This method is also explained in Chapter 7.

Networking

The assignment demands two modes of operation. The client that presents the information must be able to get it from a local database file or a remote one. The local mode is simple to implement, but the remote mode is harder. You have to design the network piece with RMI or sockets. Most people use RMI because it came later than sockets and is built on top of them. The early version of RMI was crude, but the current version, although it still needs another revision, is a better choice for this assignment than naked sockets. The big problem with sockets is thread management; you have to manually handle threads. RMI takes care of threads automatically, so the code is simpler. Some want to argue the merits of one over the other, but why not do that after passing the certification exam? I don't think sockets are worth the effort for this project. However, you might love them, so I talk about them in Chapters 11, "Networking with NIO," and 12, "RMI." Unlike the database classes, Sun provides nothing to get you started on the networking portion of the assignment.

Database Transparency

You can write a lot of fancy code so that the client handles the local database interaction one way and the network database another way. Here's a hint, however: If you design your solution the best way, there is no local– or network mode–specific code in the client. That is one of the challenges: Can you design the architecture in such a way that the database location is transparent to the client? The solution to this challenge is elegant, but not obvious. The trick is to use one interface, but have the signatures present the exact same types to the client when the database methods are called, regardless of whether the database was created by the factory from a local file or on the other side of the network through RMI. Also, the assignment forces you to build a database connection factory that generates a local or remote database connection based on command-line parameters. This factory is a marvelous example of the power behind design patterns. This design pattern is demonstrated in Chapter 9, "Interfaces," where you see a clear reason for having interfaces.

Design Choices

Some people can code fast and furiously. However, they are taking chances and might overlook important details, so what they end up doing is quickly building something that will fail even faster. There are many ways to design the GUI and the network pieces, but you need to make sure you are using a reasonable approach and are able to justify why you chose it.

One of the documents you must include in your certification project is the DESIGN_CHOICES.TXT file. In it, you list some of the major design choices you made and explain your choices by describing their main advantages and disadvantages. Also, you need to compare the design and implementation objectives with the advantages and disadvantages of your choices.

Pearson IT Certification Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Pearson IT Certification and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Pearson IT Certification products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.pearsonitcertification.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020