Cover
Half Title
Title Page
Copyright Page
Table of Contents
About the Author
Introduction
Previous Knowledge and Target Audience
Working with This Book
The Suggested Solutions
Use of This Book
Required Software
Used Java Version in the Book
JVM
Development Environment
Conventions
Helping Captain CiaoCiao and Bonny Brain
1 Introduction to the Java Ecosystem
Bytecode and JVM
Porting Java Programs
Tools for Java Developers
Get to Know Error Messages of the IDE
Suggested Solutions
Porting Java Programs
Get to Know Error Messages of the IDE
2 Imperative Programming
Screen Output
Learn about the SVG Specification
Write an SVG Circle on the Console
Variables and Data Types
Access Variables and Output Their Assignments
Quiz: Value Ranges
Quiz: Does This Add Up?
Generate Random Circles
Quiz: Dazed and Confused
Process User Input
Expressions, Operands, and Operators
Quiz: Check In-Between
Check If Loot Can Be Shared Fairly
Do Two Numbers Share the Same Digit?
Convert Currency Amount to Coins
One Bottle of Rum, Ten Bottles of Rum
Quiz: The Zero Effect
Control Flow
Payday
Quiz: Wrong Branching
Convert Liters
Create SVG Circles with Random Colors
Quiz: To Which Block Does the Else Belong?
Quiz: Recognize Negative Days and Hours
Evaluate Input Strings for Approval
Rewrite Switch Statement to Switch Expression
Loops
Create Rotated SVG Rectangles
Create SVG-Pearl-Chain
Sum Numbers from the Command Line
Go through a Mathematical Phenomenon
Quiz: How Many Stars?
Calculate Products for Faculties
Determine If a Number Is Formed by Factorial
Find the Smallest and Largest Digit of a Number
Quiz: Not Like This from 1 to 100
A Flag in the Wind through Nested Loops
Output Simple Chessboard
It’s Christmastime: Displaying Trees with Ornaments
Draw Fishy Stitching Motifs
Trying Instead of Thinking
Get the Number of Digits of a Number
Methods
Drawing Hearts
Implement Overloaded Line Methods
Standing Straight
Create a Multiplication Table
Cistercian Numerals Script
Quiz: What Does Ding-Dong Do? (Recursion)
Quiz: Repdigit (Recursion)
Calculate Collatz Sequence (Recursion)
Ancient Egyptian Multiplication (Recursion)
Suggested Solutions
Write an SVG Circle on the Console
Access Variables and Output Their Assignments
Quiz: Value Ranges
Quiz: Does This Add Up?
Generate Random Circles
Quiz: Dazed and Confused
Process User Input
Quiz: Check In-Between
Check If Loot Can Be Shared Fairly
Do Two Numbers Share the Same Digit?
Convert Currency Amount to Coins
One Bottle of Rum, Ten Bottles of Rum
Quiz: The Zero Effect
Payday
Quiz: Wrong Branching
Convert Liters
Create SVG Circles with Random Colors
Quiz: To Which Block Does the Else Belong?
Quiz: Recognize Negative Days and Hours
Evaluate Input Strings for Approval
Rewrite Switch Statement to Switch Expression
Create Rotated SVG Rectangles
Create SVG-Pearl-Chain
Sum Numbers from the Command Line
Go through a Mathematical Phenomenon
Quiz: How Many Stars?
Calculate Products for Faculties
Determine If a Number Is Formed by Factorial
Find the Smallest and Largest Digit of a Number
Quiz: Not Like This from 1 to 100
A Flag in the Wind through Nested Loops
Output Simple Chessboard
It’s Christmastime: Displaying Trees with Ornaments
Draw Fishy Stitching Motifs
Trying Instead of Thinking
Get the Number of Digits of a Number
Drawing Hearts
Implement Overloaded Line Methods
Standing Straight
Create a Multiplication Table
Cistercian Numerals Script
Quiz: What Does Ding-Dong Do? (Recursion)
Quiz: Repdigit (Recursion)
Calculate Collatz Sequence (Recursion)
Ancient Egyptian Multiplication (Recursion)
3 Classes, Objects, and Packages
Creating Objects
Draw Polygons
Working with References
Quiz: The Short Life of Points
Build Triangles
Quiz: == vs. equals(…)
Quiz: Protect against NullPointerException
Suggested Solutions
Draw Polygons
Quiz: The Short Life of Points
Build Triangles
Quiz: == vs. equals(…)
Quiz: Protect against NullPointerException
Note
4 Arrays
Everything Has a Type
Quiz: Array Types
One-Dimensional Arrays
Loop Arrays and Output Wind Speed, Wind Direction
Detect Continuous Revenue Growth
Array of Points
Search Consecutive Strings and Determine If Salty Snook Is Coming
Reverse an Array
Find the Nearest Cinema
Raid the Candy Store and Share Fairly
Enhanced for Loop
Numbers Well Shuffled
Draw Mountains
Two- and Multidimensional Arrays
Check Mini-Sudoku for Valid Solution
Enlarge Image
Variable Argument Lists
Create SVG Polygons with a Variable Number of Coordinates
Check for Approval
Help, Tetraphobia! Put All Fours Last
The Utility Class Arrays
Quiz: Copy Arrays
Quiz: Compare Arrays
Suggested Solutions
Quiz: Array Types
Loop Arrays and Output Wind Speed, Wind Direction
Reverse an Array
Array of Points
Search Consecutive Strings and Determine if Salty Snook is Coming
Reverse an Array
Find the Nearest Cinema
Raid the Candy Store and Share Fairly
Draw Mountains
Check Mini-Sudoku for Valid Solution
Enlarge Image
Create SVG Polygons with Variable Number of Coordinates
Check for Approval
Help, Tetraphobia! Put All Fours Last
Quiz: Copy Arrays
Quiz: Compare Arrays
5 Character and String Processing
The String Class and Its Members
Quiz: Is String a Built-In Keyword?
Building HTML Elements with Simple Concatenation
Check Safe Transmission by Doubling Characters
Swap Y and Z
Give Defiant Answers
Quiz: String Comparisons with == and Equals(…)
Quiz: Is Equals(…) Symmetric?
Test Strings for Palindrome Property
Check if Captain CiaoCiao is in the Middle
Find the Shortest Name in the Array
Count String Occurrences
Determine the Larger Crew Size
Build Diamonds
Check for a Good Password
Bake Peanut Butter Cookies
Calculate Sum of Digits
Decolumnize Texts
Draw a Meadow with Favorite Flowers
Detect Repetitions
Constrain Line Boundaries and Wrap Lines
Quiz: How Many String Objects?
Test If the Fruit Is Wrapped in Chocolate
From Top to Bottom, from Left to Right
Dynamic Strings with StringBuilder
Fill Strings
Practicing the Alphabet with a Parrot
Quiz: Lightly Attached
Convert Number to Textual Unary Encoding
Lose Weight by Moving Digits
Remove Vowels
Don’t Shoot the Messenger
Compress Repeated Spaces
Insert and Remove Crackles and Pops
Split CamelCase Strings
Underline Words
Implement Caesar Encryption
Suggested Solutions
Quiz: Is String a Built-In Keyword?
Building HTML Elements with Simple Concatenation
Check Safe Transmission by Doubling Characters
Swap Y and Z
Give Defiant Answers
Quiz: String Comparisons with == and Equals(…)
Quiz: Is Equals(…) Symmetric?
Test Strings for Palindrome Property
Check if Captain CiaoCiao is in the Middle
Find the Shortest Name in the Array
Count String Occurrences
Determine the Larger Crew Size
Build Diamonds
Check for a Good Password
Bake Peanut Butter Cookies
Calculate Sum of Digits
Decolumnize Texts
Draw a Meadow with Favorite Flowers
Detect Repetitions
Constrain Line Boundaries and Wrap Lines
Quiz: How Many String Objects?
Test if the Fruit is Wrapped in Chocolate
From Top to Bottom, from Left to Right
Fill Strings
Practicing the Alphabet with a Parrot
Quiz: Lightly Attached
Convert Number to Textual Unary Encoding
Lose Weight by Moving Digits
Remove Vowels
Don’t Shoot the Messenger
Compress Repeated Spaces
Insert and Remove Crackles and Pops
Split CamelCase Strings
Underline Words
Implement Caesar Encryption
6 Writing Your Own Classes
Class Declaration and Object Properties
Declare Radio with Instance Variables and a Main Program
Implementing Methods of a Radio
Private Parts: Make Instance Variables Private
Create Setters and Getters
Static Variables Methods
Convert Station Names to Frequencies
Write Log Output with a Tracer Class
Quiz: Nothing Stolen
Simple Enumerations
Give Radio an AM–FM Modulation
Set Valid Start and End Frequency for Modulation
Constructors
Writing Radio Constructors
Implement Copy Constructor
Realize Factory Methods
Associations
Connect Monitor Tube with TV
Quiz: Association, Composition, and Aggregation
Add Radios with a 1:n Association to the Ship
Inheritance
Introduce Abstraction into Electrical Devices via Inheritance
Quiz: Three, Two, and One
Quiz: Private and Protected Constructor
Determine the Number of Switched on Electrical Devices
Ship Should Hold Any Electronic Device
Take Working Radios on the Ship
Solve Equivalence Test with Pattern Variable
Fire Alarm Does Not Go Off: Overriding Methods
Calling the Methods of the Superclass
Polymorphism and Dynamic Binding
Holiday! Switch Off All Devices
The Big Move
Quiz: Bumbo Is a Great Drink
Quiz: Vodka with Taste
Quiz: Rum-Paradise
Abstract Classes and Abstract Methods
Quiz: Consumer Devices as an Abstract Superclass?
TimerTask as an Example for an Abstract Class
Suggested Solutions
Declare Radio with Instance Variables and a Main Program
Implementing Methods of a Radio
Private Parts: Make Instance Variables Private
Create Setters and Getters
Convert Station Names to Frequencies
Write Log Output with a Tracer Class
Quiz: Nothing Stolen
Give Radio an AM–FM Modulation
Set Valid Start and End Frequency for Modulation
Writing Radio Constructors
Implement Copy Constructor
Realize Factory Methods
Connect Monitor Tube with TV
Quiz: Association, Composition, and Aggregation
Add Radios with a 1:n Association to the Ship
Introduce Abstraction into Electrical Devices via Inheritance
Quiz: Three, Two, and One
Quiz: Private and Protected Constructor
Determine Number of Switched on Electrical Devices
Ship Should Hold Any Electronic Device
Take Working Radios on the Ship
Solve Equivalence Test with Pattern Variable
Fire Alarm Does Not Go Off: Overriding Methods
Calling the Methods of the Superclass
Holiday! Switch Off All Devices
The Big Move
Quiz: Bumbo Is a Great Drink
Quiz: Vodka with Taste
Quiz: Rum-Paradise
Quiz: Consumer Devices as an Abstract Superclass?
TimerTask as an Example for an Abstract Class
Note
7 Records, Interfaces, Enumerations, and Sealed Classes
Records
Quiz: Which Statements Are True for Records?
Develop Record for Complex Numbers
Quiz: Records with Static Variables
Record Patterns
Interfaces
Compare Consumption of Electrical Devices
Find Electronic Devices with the Highest Power Consumption
Use Comparator Interface for Sorting
Static and Default Methods in Interfaces
Delete Selected Elements with Predicate
Enumeration Types (enum)
Enumeration for Candy
Deliver Random Candies
Tagging Candy with Addictive Value
Interface Implementations via an enum
Quiz: Aviso and Brig
Suggested Solutions
Quiz: Which Statements Are True for Records?
Quiz: Records with Static Variables
Quiz: Records with Static Variables
Compare Consumption of Electrical Devices
Find Electronic Devices with the Highest Power Consumption
Use Comparator Interface for Sorting
Static and Default Methods in Interfaces
Delete Selected Elements with Predicate
Enumeration for Candy
Deliver Random Candies
Tagging Candy with Addictive Value
Interface Implementations via an enum
Quiz: Aviso and Brig
8 Nested Types
Declare Nested Types
Set AM–FM Modulation to Radio Type
Write Three Kinds of Watt-Comparator Implementations
Nested Types Quiz
Quiz: Pirate Could Have Waved
Quiz: Name in a Bottle
Quiz: Get Me Another Bottle of Rum
Suggested Solutions
Set AM–FM Modulation to Radio Type
Write Three Kinds of Watt-Comparator Implementations
Quiz: Pirate Could Have Waved
Quiz: Name in a Bottle
Quiz: Get Me another Bottle of Rum
9 Exception Handling
Catching Exceptions
Get the Longest Line of a File
Identify Exceptions, Laughing All the Time
Convert String Array to Int Array and Be Lenient on Nonnumbers
Quiz: And Finally
Quiz: A Lonely Try
Quiz: Well Caught
Quiz: Too Much of a Good Thing
Quiz: Try-Catch in Inheritance
Throwing Custom Exceptions
Quiz: Throw and Throws
Quiz: The Division Fails
Writing Your Own Exception Classes
Show Impossible Watt with Own Exception
Quiz: Potatoes or Other Vegetables
Try-with-Resources
Write Current Date to File
Read Notes and Write Them to a New ABC File
Quiz: Excluded
Suggested Solutions
Get the Longest Line of a File
Identify Exceptions, Laughing All the Time
Convert String Array to Int Array and Be Lenient on Nonnumbers
Quiz: And Finally
Quiz: A Lonely Try
Quiz: Well Caught
Quiz: Too Much of a Good Thing
Quiz: Try-Catch in Inheritance
Quiz: Throw and Throws
Quiz: The Division Fails
Show Impossible Watt with Own Exception
Quiz: Potatoes or Other Vegetables
Write Current Date to File
Read Notes and Write Them to a New ABC File
Quiz: Excluded
10 Lambda Expressions and Functional Programming
Lambda Expressions
Quiz: Recognize Valid Functional Interfaces
Quiz: From Interface Implementation to Lambda Expression
Write Lambda Expressions for Functional Interfaces
Quiz: Write Lambda Expressions Like This?
Developing Lambda Expressions
Quiz: Contents of the Package java.util.function
Quiz: Know Functional Interfaces for Mappings
Method and Constructor References
Rewriting Lambda Expressions
Selected Functional Interfaces
Delete Entries, Remove Comments, Convert to CSV
Suggested Solutions
Quiz: Recognize Valid Functional Interfaces
Quiz: From Interface Implementation to Lambda Expression
Write Lambda Expressions for Functional Interfaces
Quiz: Write Lambda Expressions Like This?
Developing Lambda Expressions
Quiz: Contents of the Package java.util.function
Quiz: Know Functional Interfaces for Mappings
Rewriting Lambda Expressions
Delete Entries, Remove Comments, and Convert to CSV
Note
11 Special Types from the Java Class Library
Absolute Superclass java.lang.Object
Generate equals(Object) and hashCode()
Existing equals(Object) Implementations
Interfaces Comparator and Comparable
Quiz: Natural Order Or Not?
Handle Superheroes
Compare Superheroes
Concatenate Hero Comparators
Using a Key Extractor to Easily Create a Comparator
Sort Points by Distance to Center
Find Stores Nearby
Autoboxing
Quiz: Handling Null Reference in Unboxing
Quiz: Unboxing Surprise
Suggested Solutions
Generate equals(Object) and hashCode()
Existing equals(Object) Implementations
Quiz: Natural Order Or Not?
Compare Superheroes
Concatenate Hero Comparators
Using a Key Extractor to Easily Create a Comparator
Sort Points by Distance to Center
Find Stores Nearby
Quiz: Handling Null Reference in Unboxing
Quiz: Unboxing Surprise
Notes
Appendix A: Most Frequent Types and Methods in the Java Universe
A.1 Packages with the Most Common Types
A.2 100 Most Common Types
A.3 100 Most Common Methods
A.4 100 Most Common Methods Including Parameter List