CERTguide Sun Certified Java Architect 310-051 Study Guide

What is the Java Architect Exam all about?

According to Sun:

“"This certification is for enterprise architects responsible for architecting and designing Java[tm] 2 Platform, Enterprise Edition (J2EE[tm]) compliant applications, which are scalable, flexible and highly secure. Certification consists of three elements: a knowledge-based multiple choice exam, an assignment and essay exam."

You have one concept based exam as well as one project exam to take. The concept based exam consists of MC and Fill in the blank questions.

This exam has its focus on design pattern.

You do NOT need to obtain CJP before attempting this certification.

What J2EE version are we dealing with?

Currently the exam is based on earlier version of Java2. As of the time of this writing V1.4 DRAFT has just been released.

"The Java 2 Platform, Enterprise Edition (J2EE) defines the standard for developing multi-tier enterprise applications. The J2EE 1.4 platform specification introduces new APIs which implement core Web services protoccols stack. It also introduces new Management and Deployment APIs, new versions of the JavaServer PagesTM, Enterprise JavaBeansTM, and Connector APIs, along with other features which establish J2EE 1.4 as a premier Web services and enterprise application intergration platform." http://java.sun.com/j2ee/

The link to download the draft is at: http://java.sun.com/j2ee/download.html#platformspec

You must have experience in Object Oriented programming! Java is heavily OO! J2EE is highly component based! If you are new to the world of programming, this exam may not be the right thing to go for.

What is J2EE?

"Short for Java 2 Platform Enterprise Edition. J2EE is a platform-independent, Java-centric environment from Sun for developing, building and deploying Web-based enterprise applications online. The J2EE platform consists of a set of services, APIs, and protocols that provide the functionality for developing multitiered, Web-based applications."

http://www.webopedia.com/TERM/J/J2EE.html

Key features at a glance:

n At the client tier J2EE supports pure HTML, Java applets and Java applications

n J2EE relies on Java Server Pages and servlet code to present data to the client.

n Enterprise JavaBeans provide a layer where the platform's logic is stored.

n EJB server provides threading, concurrency, security and memory management.

n Java Database Connectivity acts as the standard interface for Java databases.

n Java servlet API provides consistency for developers

What is JDBC?

"Short for Java Database Connectivity, a Java API that enables Java programs to execute SQL statements. This allows Java programs to interact with any SQL-compliant database. Since nearly all relational database management systems (DBMSs) support SQL, and because Java itself runs on most platforms, JDBC makes it possible to write a single database application that can run on different platforms and interact with different DBMSs."

http://www.webopedia.com/TERM/J/JDBC.html

What is EJB?

n short for Enterprise JavaBeans

n Java API developed by Sun Microsystems

n defines a component architecture for multi-tier client/server systems

n allow developers to focus on the actual business architecture of the model

n developers can design or purchase the needed EJB components and arrange them

What is Servlet?

n a Java applet

n runs on a server

n usually refers to a Java applet that runs within a Web server environment

n becoming increasingly popular as an alternative to CGI programs

n persistent - once it is started, it stays in memory and can fulfill multiple requests

n run faster as there's no wasted time in setting up and tearing down the process

What is JSP?

n Short for Java Server Page

n server-side

n an extension to the Java servlet technology

n dynamic scripting capability - works in tandem with HTML code - provides a more convenient way to code a servlet

n processes HTTP requests and generates responses like any servlet.

n separate the page logic from the static elements

n translated into Java servlet before being run

n JSP translator is triggered by the .jsp file name extension in a URL

What is Java?

n high-level programming language

n developed by Sun Microsystems

n object-oriented

n language is similar to C++ yet simplified

n source code files with a .java extension

n bytecode files with a .class extension

n bytecode executed by a Java interpreter

n “compiled” Java code can run on most computers

n Java interpreters and runtime environments are known as Java Virtual Machines

n small Java applications called Java applets can be downloaded from a Web server and run on your computer by a Java-compatible Web browser

It has been said that, to a certain extent, Java is the “no pointer” variant of C++. Pointer is the most troublesome part of programming.

What is UML?

n Short for Unified Modeling Language

n developed under the Object Management Group

n a general-purpose notational language

n used mainly for specifying and visualizing complex software project

n lots of diagram and drawing!

The goals of UML (http://microgold.com/Stage/UML_FAQ.html):

n To model systems using object-oriented concepts

n To establish an explicit coupling to conceptual as well as executable artifacts

n To address the issues of scale inherent in complex, mission-critical systems

n To create a method usable by both humans and machines

As described by the UML FAQ at http://microgold.com/Stage/UML_FAQ.html#UML6 , from the inside, the Unified Modeling Language consists of three things:

n A formal metamodel

n A graphical notation

n A set of idioms of usage

while from the outside, the Unified Modeling Language encompasses a number of models that can be rendered in a variety of projections:

n Use-case diagrams

n Class diagrams

n State-machine diagrams

n Message-trace diagrams

n Object-message diagrams

n Process diagrams

n Module diagrams

n Platform diagrams

What is J2EE pattern?

n documented in a template form

n represents a recurring solution to a problem

n useful for communicating design solutions to developers and architects - we identify and document problem characteristics using the pattern template

n it itself exists at a level of abstraction higher than strategies

n describes and documents solution at a certain level of abstraction

n sections of a pattern template:

u Context – it sets the environment under which the pattern exists.

u Problem – it describes the design issues faced by us.

u Forces – it lists the reasons that affect the problem and the solution.

u Solution – it describes in brief the solution approach

u Structure – it uses UML class diagrams to show the solution’s basic structure

u Strategies – it describes the different ways of having a pattern implemented.

u Consequences – it represents the pattern trade-offs

n context includes:

u environment

u surroundings

u situation

u interrelated conditions

n problem:

u unsettled question

u specified by a series of causes and effects

n solution:

u answer to the problem

u a solution remains a candidate pattern until it has been verified in at least three different systems

Learning J2EE

Before you are ready to cram-study for the exam, go learn the language – make yourself a practical Java programmer. Below are the links that provide very good Java tutorials. Make sure you go through them in detail:

You should visit the official J2EE site and make yourself familiar with everything introduced in there. The URL is http://java.sun.com/j2ee/

Remember, the exam does not only test your memorization skill – it does test your real programming skills!

To prepare for the project exam as well as to truly master J2EE, you are recommended to go through the official Pet Store sample provided by Sun:

“The Java Pet Store for Web Services provides documentation, full source code for the Enterprise JavaBeansTM (EJBTM) architecture, JavaServer PagesTM (JSPTM) technology, tag libraries, and servlets that build the application.”

http://java.sun.com/features/2002/07/ws-petstore.html

What you will find in this Pet Store includes:

n An implementation of work flow to process purchase orders

n An implementation of an asynchronous architecture for Web Services

n A caching tag for caching data in the Web tier for performance improvements

n A transformation of XML schema between two trading partners

n A variety of Design Patterns through specific examples.

To download the Pet Store source codes, visit: http://java.sun.com/blueprints/code/

It is also recommended that you go through the official J2EE tutorial at http://java.sun.com/j2ee/tutorial/ . This tutorial includes the following topics:

n Distributed Multitiered Applications

n J2EE Components

n J2EE Clients

n Web Components

n Business Components

n Enterprise Information System Tier

n J2EE Containers

n Container Services

n Container Types

n Packaging

n Development Roles

n J2EE Product Provider