A Programmer’s Guide to Java® SE 8 Oracle Certified Associate (OCA)

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A Programmer’s Guide to Java® SE 8

Oracle Certified Associate (OCA)

A Comprehensive Primer

Khalid A. Mughal

Rolf W. Rasmussen

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ISBN-13: 978-0-13-293021-5

ISBN-10: 0-13-293021-8

Text printed in the United States on recycled paper at RR Donnelley in Crawfordsville,

Indiana.

First printing, July 2016

To the loving memory of my mother, Zubaida Begum,

and my father, Mohammed Azim

—K.A.M.

For Olivia E. Rasmussen and

Louise J. Dahlmo

—R.W.R.

Contents Overview

Figures

Tables

Examples

Foreword

Preface

1 Basics of Java Programming

2 Language Fundamentals

3 Declarations

4 Access Control

5 Operators and Expressions

6 Control Flow

7 Object-Oriented Programming

8 Fundamental Classes

9 Object Lifetime

10 The ArrayList<E> Class and Lambda Expressions

11 Date and Time

A Taking the Java SE 8 Programmer I Exam

B Exam Topics: Java SE 8 Programmer I

C Annotated Answers to Review Questions

D Solutions to Programming Exercises

E Mock Exam: Java SE 8 Programmer I

F Annotated Answers to Mock Exam I

Index

Contents

Figures

Tables

Examples

Foreword

Preface

1 Basics of Java Programming

1.1 Introduction

1.2 Classes

Declaring Members: Fields and Methods

1.3 Objects

Class Instantiation, Reference Values, and References

Object Aliases

1.4 Instance Members

Invoking Methods

1.5 Static Members

1.6 Inheritance

1.7 Associations: Aggregation and Composition

1.8 Tenets of Java

Review Questions

1.9 Java Programs

1.10 Sample Java Application

Essential Elements of a Java Application

Compiling and Running an Application

1.11 Program Output

Formatted Output

1.12 The Java Ecosystem

Object-Oriented Paradigm

Interpreted: The JVM

Architecture-Neutral and Portable Bytecode

Simplicity

Dynamic and Distributed

Robust and Secure

High Performance and Multithreaded

Review Questions

Chapter Summary

Programming Exercise

2 Language Fundamentals

2.1 Basic Language Elements

Lexical Tokens

Identifiers

Keywords

Separators

Literals

Integer Literals

Floating-Point Literals

Underscores in Numerical Literals

Boolean Literals

Character Literals

String Literals

Whitespace

Comments

Review Questions

2.2 Primitive Data Types

The Integer Types

The char Type

The Floating-Point Types

The boolean Type

Review Questions

2.3 Variable Declarations

Declaring and Initializing Variables

Reference Variables

2.4 Initial Values for Variables

Default Values for Fields

Initializing Local Variables of Primitive Data Types

Initializing Local Reference Variables

Lifetime of Variables

Review Questions

Chapter Summary

Programming Exercise

3 Declarations

3.1 Class Declarations

3.2 Method Declarations

Statements

Instance Methods and the Object Reference this

Method Overloading

3.3 Constructors

The Default Constructor

Overloaded Constructors

Review Questions

3.4 Arrays

Declaring Array Variables

Constructing an Array

Initializing an Array

Using an Array

Anonymous Arrays

Multidimensional Arrays

Sorting Arrays

Searching Arrays

Review Questions

3.5 Parameter Passing

Passing Primitive Data Values

Passing Reference Values

Passing Arrays

Array Elements as Actual Parameters

final Parameters

3.6 Variable Arity Methods

Calling a Variable Arity Method

Variable Arity and Fixed Arity Method Calls

3.7 The main() Method

Program Arguments

3.8 Enumerated Types

Declaring Type-safe Enums

Using Type-safe Enums

Selected Methods for Enum Types

Review Questions

Chapter Summary

Programming Exercise

4 Access Control

4.1 Java Source File Structure

4.2 Packages

Defining Packages

Using Packages

Compiling Code into Packages

Running Code from Packages

4.3 Searching for Classes

Review Questions

4.4 Scope Rules

Class Scope for Members

Block Scope for Local Variables

4.5 Accessibility Modifiers for Top-Level Type Declarations

4.6 Non-Accessibility Modifiers for Classes

abstract Classes

final Classes

Review Questions

4.7 Member Accessibility Modifiers

public Members

protected Members

Default Accessibility for Members

private Members

Review Questions

4.8 Non-Accessibility Modifiers for Members

static Members

final Members

abstract Methods

synchronized Methods

native Methods

transient Fields

volatile Fields

Review Questions

Chapter Summary

Programming Exercise

5 Operators and Expressions

5.1 Conversions

Widening and Narrowing Primitive Conversions

Widening and Narrowing Reference Conversions

Boxing and Unboxing Conversions

Other Conversions

5.2 Type Conversion Contexts

Assignment Context

Method Invocation Context

Casting Context of the Unary Type Cast Operator: (type)

Numeric Promotion Context

5.3 Precedence and Associativity Rules for Operators

5.4 Evaluation Order of Operands

Left-Hand Operand Evaluation First

Operand Evaluation before Operation Execution

Left-to-Right Evaluation of Argument Lists

5.5 Representing Integers

Calculating Two’s Complement

Converting Binary Numbers to Decimals

Converting Decimals to Binary Numbers

Relationships among Binary, Octal, and Hexadecimal Numbers

5.6 The Simple Assignment Operator =

Assigning Primitive Values

Assigning References

Multiple Assignments

Type Conversions in an Assignment Context

Review Questions

5.7 Arithmetic Operators: *, /, %, +, -

Arithmetic Operator Precedence and Associativity

Evaluation Order in Arithmetic Expressions

Range of Numeric Values

Unary Arithmetic Operators: -, +

Multiplicative Binary Operators: *, /, %

Additive Binary Operators: +, -

Numeric Promotions in Arithmetic Expressions

Arithmetic Compound Assignment Operators: *=, /=, %=, +=, -=

Review Questions

5.8 The Binary String Concatenation Operator +

5.9 Variable Increment and Decrement Operators: ++, --

The Increment Operator ++

The Decrement Operator --

Review Questions

5.10 Boolean Expressions

5.11 Relational Operators: <, <=, >, >=

5.12 Equality

Primitive Data Value Equality: ==, !=

Object Reference Equality: ==, !=

Object Value Equality

5.13 Boolean Logical Operators: !, ^, &, |

Operand Evaluation for Boolean Logical Operators

Boolean Logical Compound Assignment Operators: &=, ^=, |=

5.14 Conditional Operators: &&, ||

Short-Circuit Evaluation

5.15 Integer Bitwise Operators: ~, &, |, ^

Bitwise Compound Assignment Operators: &=, ^=, |=

Review Questions

5.16 The Conditional Operator: ?:

5.17 Other Operators: new, [], instanceof, ->

Review Questions

Chapter Summary

Programming Exercise

6 Control Flow

6.1 Overview of Control Flow Statements

6.2 Selection Statements

The Simple if Statement

The if-else Statement

The switch Statement

Review Questions

6.3 Iteration Statements

The while Statement

The do-while Statement

The for(;;) Statement

The for(:) Statement

6.4 Transfer Statements

Labeled Statements

The break Statement

The continue Statement

The return Statement

Review Questions

6.5 Stack-Based Execution and Exception Propagation

6.6 Exception Types

The Exception Class

The RuntimeException Class

The Error Class

Checked and Unchecked Exceptions

Defining Customized Exceptions

6.7 Exception Handling: try, catch, and finally

The try Block

The catch Clause

The finally Clause

6.8 The throw Statement

6.9 The throws Clause

Overriding the throws Clause

6.10 Advantages of Exception Handling

Review Questions

Chapter Summary

Programming Exercises

7 Object-Oriented Programming

7.1 Single Implementation Inheritance

Relationships: is-a and has-a

The Supertype–Subtype Relationship

7.2 Overriding Methods

Instance Method Overriding

Covariant return in Overriding Methods

Overriding versus Overloading

7.3 Hiding Members

Field Hiding

Static Method Hiding

7.4 The Object Reference super

Review Questions

7.5 Chaining Constructors Using this() and super()

The this() Constructor Call

The super() Constructor Call

Review Questions

7.6 Interfaces

Defining Interfaces

Abstract Methods in Interfaces

Implementing Interfaces

Extending Interfaces

Interface References

Default Methods in Interfaces

Static Methods in Interfaces

Constants in Interfaces

Review Questions

7.7 Arrays and Subtyping

Arrays and Subtype Covariance

Array Store Check

7.8 Reference Values and Conversions

7.9 Reference Value Assignment Conversions

7.10 Method Invocation Conversions Involving References

Overloaded Method Resolution

7.11 Reference Casting and the instanceof Operator

The Cast Operator

The instanceof Operator

Review Questions

7.12 Polymorphism and Dynamic Method Lookup

7.13 Inheritance versus Aggregation

7.14 Basic Concepts in Object-Oriented Design

Encapsulation

Cohesion

Coupling

Review Questions