Oracle Certified Associate, Java SE 7 Programmer Study Guide

332 Pages·2012·3.537 MB·English

by  Richard M. Reese

www.it-ebooks.info
Oracle Certified Associate,
Java SE 7 Programmer
Study Guide
Comprehensive review of Oracle Certified Associate,
Java SE 7 Programmer Certification objectives
Richard M. Reese
professional expertise distilled
P U B L I S H I N G
BIRMINGHAM - MUMBAI
www.it-ebooks.info
Oracle Certified Associate, Java SE 7 Programmer
Study Guide
Copyright © 2012 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, without the prior written
permission of the publisher, except in the case of brief quotations embedded in
critical articles or reviews.
Every effort has been made in the preparation of this book to ensure the accuracy
of the information presented. However, the information contained in this book is
sold without warranty, either express or implied. Neither the author, nor Packt
Publishing, and its dealers and distributors will be held liable for any damages
caused or alleged to be caused directly or indirectly by this book.
Packt Publishing has endeavored to provide trademark information about all of the
companies and products mentioned in this book by the appropriate use of capitals.
However, Packt Publishing cannot guarantee the accuracy of this information.
First published: August 2012
Production Reference: 1160812
Published by Packt Publishing Ltd.
Livery Place
35 Livery Street
Birmingham B3 2PB, UK.
ISBN 978-1-84968-732-4
www.packtpub.com
Cover Image by Mark Holland ([email protected])
www.it-ebooks.info
Credits
Author Project Coordinator
Richard M. Reese Joel Goveya
Reviewers Proofreader
Edward E. Griebel Jr. Linda Morris
Abraham Tehrani
Indexer
Hemangini Bari
Acquisition Editor
Dhwani Devater
Graphics
Manu Joseph
Lead Technical Editor
Susmita Panda
Production Coordinator
Nilesh R. Mohite
Technical Editor
Vrinda Amberkar
Cover Work
Nilesh R. Mohite
www.it-ebooks.info
About the Author
Richard Reese is an Associate Professor for Computer Science at Tarleton State
University in Stephenville, Texas. Previously, he has worked in the Aerospace and
Telephony industries for over 17 years. He earned his Ph.D. in Computer Science
from Texas A&M University and served 4 years in the Air Force primarily in the field
of Communication Intelligence.
Outside the classroom, he enjoys tending his vegetable garden, maintaining his
aquariums and greenhouse, and playing with his dog, Zoey. He also enjoys reading
a variety of technical and non-technical material.
Richard has written numerous publications and wrote EJB 3.1 Cookbook and the Java 7
New Features Cookbook for Packt Publishing.
No book can be written without the help of others. To this end I
am thankful for the support of Karla, my wife, whose patience and
reviews have made this effort possible. In addition, I would like to
thank the editorial staff of Packt and the reviewers for their input
which has resulted in a much better book than it might otherwise
have been.
www.it-ebooks.info
About the Reviewers
Edward E. Griebel Jr. was first introduced to computers in elementary school
through LOGO on an Apple ][ and "The Oregon Trail" on a VAX. Pursuing his
interest in computers, Ed graduated from Bucknell University with a degree in
Computer Engineering. At his first job he quickly realized he didn't know everything
that there was to know about Computer Programming. Ed has spent the past
20 years honing his skills in the securities trading, telecommunications, payroll
processing, and machine-to-machine communications industries as a Developer,
Team Lead, Consultant, and Mentor. Currently working on Enterprise Development
in Java EE, Ed feels that any day spent writing code is a good day.
Away from the keyboard, Ed enjoys road trips with his wife and three children, and
playing Ultimate Frisbee and Xbox. He also volunteers as his sons' scout leader and
on committees at his church.
I would like to thank my wife and three children who are by now
used to letting me sleep late after long nights at the computer.
Abraham Tehrani has over a decade of experience in Software Development as a
Developer and QA Engineer. He is passionate about quality and technology.
I would like to thank my fiancé for her support and love. I would
also like to thank my friends and family for supporting me in all of
my endeavors.
www.it-ebooks.info
www.PacktPub.com
Support files, eBooks, discount offers and more
You might want to visit www.PacktPub.com for support files and downloads related to
your book.
Did you know that Packt offers eBook versions of every book published, with PDF and ePub
files available? You can upgrade to the eBook version at www.PacktPub.com and as a print
book customer, you are entitled to a discount on the eBook copy. Get in touch with us at
[email protected] for more details.
At www.PacktPub.com, you can also read a collection of free technical articles, sign up for a
range of free newsletters and receive exclusive discounts and offers on Packt books and eBooks.
http://PacktLib.PacktPub.com
Do you need instant solutions to your IT questions? PacktLib is Packt's online digital book
library. Here, you can access, read and search across Packt's entire library of books.
Why Subscribe?
• Fully searchable across every book published by Packt
• Copy and paste, print and bookmark content
• On demand and accessible via web browser
Free Access for Packt account holders
If you have an account with Packt at www.PacktPub.com, you can use this to access PacktLib
today and view nine entirely free books. Simply use your login credentials for immediate access.
Instant Updates on New Packt Books
Get notified! Find out when new books are published by following @PacktEnterprise on
Twitter, or the Packt Enterprise Facebook page.
www.it-ebooks.info
Table of Contents
Preface 1
Chapter 1: Getting Started with Java 7
Understanding Java as a technology 7
Object-oriented software development 8
OOP principles 10
Examining the types of Java applications 12
Exploring the structure of a Java console program 15
A simple Java application 15
Package 17
Import 17
The Customer class 18
Instance variables 18
Methods 18
The CustomerDriver class' main method 19
Exploring the structure of a class 19
Classes, interfaces, and objects 20
Classes and objects 20
Constructors 21
Interfaces 21
Methods 22
Method declaration 22
Method signature 23
The main method 24
Access modifiers 25
Documentation 26
Comments 27
Java naming conventions 28
Using Javadocs 28
Investigating the Java application development process 29
Compiling a Java application 30
SDK file structure 31
www.it-ebooks.info
Table of Contents
IDE file structure 31
Developing Java applications without an IDE 32
Java environment 33
Annotations 35
Java class libraries 35
Summary 36
Certification objectives covered 37
Test your knowledge 37
Chapter 2: Java Data Types and Their Usage 39
Understanding how Java handles data 40
Java identifiers, objects, and memory 40
Stack and heap 40
Declaring a variable 45
Primitive data types 46
Wrapper classes and autoboxing 48
Initializing identifiers 49
Java constants, literals, and enumerations 51
Literals 51
Constants 56
The final keyword 57
Enumerations 57
Immutable objects 58
Instance versus static data 58
Scope and lifetime 58
Scoping rules 59
Access modifiers 60
Data summary 61
Building expressions using operands and operators 61
Precedence and associativity 62
Casting 63
Working with characters and strings 64
The String, StringBuffer, and StringBuilder classes 64
Unicode characters 65
The Character class 66
The Character class – methods 66
The String class 66
String comparisons 68
Basic string methods 72
String length 73
Number/string conversions 73
Miscellaneous String methods 74
The StringBuffer and StringBuilder classes 74
Summary 75
[ ii ]
www.it-ebooks.info
Table of Contents
Certification objectives covered 76
Test your knowledge 76
Chapter 3: Decision Constructs 79
Flow of control 80
Control statement – an overview 80
Logical expressions 81
Boolean variables 81
The equality operator 82
Relational operators 82
Logical operators 83
Short circuit evaluation 85
Using the && operator 85
Using the || operator 86
Avoiding short circuit evaluation 86
The if statement 87
Nested if statements 90
The else-if variation 91
The if statement – usage issues 92
Misusing the equality operator 92
Using inverse operations 93
Using Boolean variables instead of logical expressions 94
Using true or false in a logical expression 95
The perils of not using the block statement 96
The dangling else problem 97
Conditional operator 99
The switch statement 100
Integer-based switch statements 101
Enumeration-based switch statements 103
String-based switch statements 104
String issues with the switch statement 105
Control structure issues 105
General decision constructs issues 105
Floating point number considerations 106
Special floating point values 107
Comparing floating point numbers 109
Rounding errors 110
The strictfp keyword 111
Comparing objects 111
Three basic coding activities 112
The goto statement 112
Summary 113
Certification objectives covered 114
Test your knowledge 114
[ iii ]
www.it-ebooks.info