The Java Workshop - A practical, no-nonsense guide to Java.

Key Features: \* Structured to let you progress and pause learning at your own pace, on your own terms \* Complete step-by-step exercises and open-ended activities to help build and reinforce key skills \* Ideal for beginners who are looking to get started with Java for the first time What You Will Learn: \* Get to grips with the fundamental concepts of the Java language \* Write clean and well-commented code that's easy to maintain \* Build a Java project with JAR files and learn about tools like Maven and Gradle \* Debug and compile logical errors and handle exceptions in your programs \* Learn how to use third-party libraries and software development kits (SDKs) \* Use Java Database Connectivity (JDBC) to work with information stored in databases \* Understand how you can keep data secure with cryptography and encryption \* Learn how to keep your development process bug-free with unit testing About: You already know you want to learn Java, but which approach works best for you? Whether you want to build web applications, enterprise software, or work on your own side projects The Java Workshop is heavily geared towards getting you build-ready for the real world. A step-by-step approach to learning helps you develop and reinforce key skills in a way that feels engaging and rewarding, without dragging you down into long-running lectures on dry, underlying theory. We use real examples that lead to real results. As you progress through The Java Workshop, you’ll find key concepts broken down into convenient, individual sections. Designed to accommodate short reading sessions as well as intense, laser-focused study, you’ll find that the included step-by-step exercises and open-ended activities help you embed and reinforce what you’ve learned in a hands-on, practical context. With every chapter carefully designed to let you learn at your own pace, you get to decide how quickly you progress and how you fit learning within your schedule. Cover......Page 1 FM......Page 2 Copyright......Page 3 Table of Contents......Page 4 Preface......Page 22 Chapter 1: Getting Started......Page 28 Writing, Compiling, and Executing Your Hello World Program......Page 29 Exercise 1: Creating Your Hello World Program in Java......Page 30 Basic Syntax and Naming Conventions......Page 36 Printing Out Different Data Types......Page 38 Exercise 2: Printing Different Types of Data......Page 39 Primitive versus Reference Data Types......Page 42 Null......Page 43 Chars and Strings......Page 44 Exercise 3: Declaring Strings......Page 45 Doing Some Math......Page 46 Exercise 4: Solving a Simple Trigonometry Problem......Page 47 Comments Help You to Share Code......Page 49 Exercise 5: Running the Code from the CLI......Page 50 Activity 1: Obtaining the Minimum of Two Numbers......Page 51 Summary......Page 52 Chapter 2: Learning the Basics......Page 54 Controlling the Flow of Your Programs......Page 55 Exercise 1: Creating a Basic if Statement......Page 56 Comparison Operators......Page 59 Exercise 2: Using Java Comparison Operators......Page 60 Exercise 3: Implementing a Nested if Statement......Page 62 Branching Two Ways with if and else......Page 63 Exercise 4: Using if and else Statements......Page 64 Using Complex Conditionals......Page 66 Exercise 5: Using Logical Operators to Create Complex Conditionals......Page 67 Using Arithmetic Operators in an if Condition......Page 69 Exercise 6: Using the Ternary Operator......Page 70 Exercise 7: Comparing Decimal Values......Page 72 Comparing Strings......Page 73 Using Switch Statements......Page 75 Exercise 8: Using Switch......Page 76 Exercise 9: Allowing Cases to Fall Through......Page 77 Exercise 10: Using Java 12 Switch Statements......Page 79 Looping and Performing Repetitive Tasks......Page 81 Exercise 11: Using a Classic for Loop......Page 82 Exercise 12: Using an Enhanced for Loop......Page 83 Jumping Out of Loops with Break and Continue......Page 84 Exercise 13: Using Break and Continue......Page 85 Using the While Loop......Page 86 Exercise 14: Using a While Loop......Page 87 Using the Do-While Loop......Page 88 Exercise 15: Testing Command-Line Arguments......Page 89 Exercise 16: Converting String to Integers and Doubles......Page 91 Diving Deeper into Variables – Immutability......Page 92 Using Static Values......Page 93 Using Local Variable Type Inference......Page 94 Activity 1: Taking Input and Comparing Ranges......Page 95 Summary......Page 96 Chapter 3: Object-Oriented Programming......Page 98 The Anatomy of a Class......Page 99 Working with Objects in Java......Page 101 Checking the Precedence of a Class with instanceof......Page 105 Exercise 1: Creating the WordTool Class......Page 106 Activity 1: Adding the Frequency-of-Symbol Calculation to WordTool......Page 114 Inheritance in Java......Page 115 Overriding and Hiding Methods......Page 117 Avoiding Overriding: Final Classes and Methods......Page 120 Overloading Methods and Constructors......Page 121 Recursion......Page 123 Annotations......Page 125 Interfaces......Page 129 Inner Classes......Page 130 Documenting with JavaDoc......Page 132 Activity 2: Adding Documentation to WordTool......Page 137 Summary......Page 138 Chapter 4: Collections, Lists, and Java's Built-In APIs......Page 140 Introduction......Page 141 Arrays......Page 142 Activity 1: Searching for Multiple Occurrences in an Array......Page 150 Sets......Page 151 Lists......Page 157 Exercise 1: Creating the AnalyzeInput Application......Page 163 Maps......Page 165 Iterating through Collections......Page 168 Exercise 2: Bringing Analytics into the AnalyzeInput Application......Page 172 Sorting Collections......Page 175 Exercise 3: Sort the Results from the AnalyzeInput Application......Page 177 Properties......Page 182 Activity 2: Iterating through Large Lists......Page 187 Summary......Page 188 Chapter 5: Exceptions......Page 190 A Simple Exception Example......Page 191 NullPointerException – Have No Fear......Page 196 Catching Exceptions......Page 199 Exercise 1: Logging Exceptions......Page 204 Throws and Throw......Page 206 Exercise 2: Breaking the Law (and Fixing It)......Page 208 The finally Block......Page 211 Activity 1: Designing an Exception Class Logging Data......Page 212 Best Practices for Handling Exceptions......Page 213 Summary......Page 217 Chapter 6: Libraries, Packages, and Modules......Page 220 Importing Classes......Page 221 Exercise 1: Importing Classes......Page 222 Fully Qualified Class Names......Page 224 Importing All Classes in a Package......Page 225 Static Imports......Page 226 Naming Your Package......Page 227 Directories and Packages......Page 228 Exercise 2: Creating a Package for a Fitness Tracking App......Page 229 Building JAR Files......Page 235 Exercise 3: Building a JAR File......Page 236 Defining the Manifest......Page 237 Exercise 4: Building an Executable JAR File......Page 238 Build Tools......Page 239 Maven......Page 240 Exercise 5: Creating a Maven Project......Page 241 Exercise 6: Adding Java Sources to the Maven Project......Page 244 Exercise 7: Building the Maven Project......Page 251 Exercise 8: Creating an Executable JAR with Maven......Page 252 Using Gradle......Page 253 Exercise 9: Creating a Gradle Project......Page 254 Exercise 10: Building an Executable JAR with Gradle......Page 256 Finding the Libraries......Page 258 Exercise 11: Adding a Third-Party Library Dependency......Page 259 Using the Apache Commons Lang Library......Page 262 Exercise 12: Using the Apache Commons Lang Library......Page 263 Using Modules......Page 264 Creating Modules......Page 266 Exercise 13: Creating a Project for a Module......Page 267 Exercise 14: Creating a Second Module Using the First One......Page 269 Activity 1: Tracking Summer High Temperatures......Page 272 Summary......Page 275 Chapter 7: Databases and JDBC......Page 278 Relational Databases......Page 279 Relational Database Management Systems......Page 280 Exercise 1: Running the H2 Database......Page 281 Exercise 2: Creating the customer Table......Page 283 Inserting Data into a Table......Page 285 Retrieving Data......Page 286 Exercise 4: Creating the email Table......Page 289 Selecting Data from Multiple Tables......Page 290 Exercise 5: Modifying email Data......Page 291 JDBC – Accessing Databases from Java......Page 292 Connecting to Databases......Page 293 Querying Data with JDBC......Page 294 Exercise 6: Querying Data with JDBC......Page 295 Using Prepared Statements......Page 299 Transactions and Rollback......Page 301 Exercise 7: Using Prepared Statements with Transactions......Page 302 Simplifying JDBC Programming......Page 304 Using Object-Relational Mapping Software......Page 305 Database Connection Pooling......Page 306 Activity 1: Track Your Progress......Page 307 Summary......Page 308 Chapter 8: Sockets, Files, and Streams......Page 310 Introduction......Page 311 Listing Files and Directories......Page 312 Separating Directories from Files......Page 316 Exercise 1: Listing the Contents of Subdirectories......Page 319 Creating and Writing to a File......Page 324 Activity 1: Writing the Directory Structure to a File......Page 329 Reading an Existing File......Page 331 Reading a Properties File......Page 333 Exercise 2: Creating a Properties File from the CLI......Page 336 What Are Streams?......Page 339 The Different Streams of the Java Language......Page 343 What Are Sockets?......Page 347 Creating a SocketServer......Page 348 Writing Data on and Reading Data from a Socket......Page 350 Activity 2: Improving the EchoServer and EchoClient Programs......Page 353 Summary......Page 355 Chapter 9: Working with HTTP......Page 358 Exploring HTTP......Page 359 Representational State Transfer......Page 361 Request Headers......Page 362 Using HttpUrlConnection......Page 363 Exercise 1: Creating a HEAD Request......Page 365 Reading the Response Data with a GET Request......Page 367 Exercise 2: Creating a GET Request......Page 368 Requesting Parameters......Page 369 Exercise 3: Sending JSON Data with POST Requests......Page 370 Parsing HTML Data......Page 373 Exercise 4: Using jsoup to Extract Data from HTML......Page 375 Delving into the java.net.http Module......Page 377 Exercise 5: Getting HTML Contents Using the java.net.http Module......Page 379 Activity 1: Using the jsoup Library to Download Files from the Web......Page 380 Summary......Page 381 Chapter 10: Encryption......Page 384 Ciphers......Page 385 Symmetric Key Encryption......Page 387 Exercise 1: Encrypting the String using Advanced Encryption Standard......Page 388 Initialization Vectors......Page 393 Exercise 2: Encrypting the String Using the RSA Asymmetric Key Encryption......Page 394 Encrypting Files......Page 398 Exercise 3: Encrypting a file......Page 399 Summary......Page 407 Chapter 11: Processes......Page 410 Launching a Process......Page 411 Sending Input to a Child Process......Page 414 Capturing the Output of a Child Process......Page 417 Storing the Output of a Child Process in a File......Page 418 Activity 1: Making a Parent Process to Launch a Child Process......Page 420 Summary......Page 422 Chapter 12: Regular Expressions......Page 424 Decrypting Regular Expressions......Page 425 Character Classes......Page 426 Quantifiers......Page 427 Escaped Characters......Page 428 Exercise 1: Implementing Regular Expressions......Page 429 Activity 1: Regular Expressions to Check If the Entrance is Entered in the Desired Format......Page 433 Regular Expressions in Java......Page 434 Exercise 2: Extracting the Domain Using Pattern Matching......Page 435 Exercise 3: Extracting Links Using Pattern Matching......Page 442 Summary......Page 449 Chapter 13: Functional Programming with Lambda Expressions......Page 452 Side Effects......Page 453 Deterministic Functions......Page 455 Exercise 1: Writing Pure Functions......Page 456 Immutability of State......Page 460 Exercise 2: Creating an Immutable Class......Page 461 Activity 1: Modifying Immutable Lists......Page 466 Immutable Collections......Page 467 Exercise 3: Overriding the String Method......Page 468 Functional Interfaces......Page 470 Lambda Expressions......Page 471 Exercise 4: Listing Spare Tires......Page 472 Summary......Page 479 Chapter 14: Recursion......Page 482 Delving into Recursion......Page 483 Exercise 1: Using Recursion to Overflow the Stack......Page 484 Exercise 2: Using Recursion to Calculate Factorials......Page 486 Processing an XML Document......Page 488 Exercise 3: Creating an XML File......Page 489 Introducing the DOM XML API......Page 492 Exercise 4: Traversing an XML Document......Page 494 Activity 1: Calculating the Fibonacci Sequence......Page 501 Summary......Page 502 Chapter 15: Processing Data with Streams......Page 504 Introduction......Page 505 Creating Streams......Page 506 Parallel Streams......Page 508 Closing Streams......Page 509 Terminal Operations......Page 511 Intermediate Operations......Page 516 Exercise 1: Using the Stream API......Page 522 Using Collectors......Page 526 I/O Streams......Page 535 Exercise 2: Converting CSV to a List......Page 537 Summary......Page 543 Chapter 6: Predicates and Other Functional Interfaces......Page 546 Predicate Interface......Page 547 Exercise 1: Defining a predicate......Page 548 Consumer Interface......Page 557 Exercise 2: Producing Side Effects......Page 558 Exercise 3: Extracting Data......Page 565 Summary......Page 569 Chapter 17: Reactive Programming with Java Flow......Page 572 Introduction......Page 573 SubmissionPublisher......Page 575 Subscriber......Page 576 Exercise 1: A Simple Application with a Single Publisher and a Single Subscriber......Page 577 Processor......Page 587 Exercise 2: Using a Processor to Convert a Stream of Strings to Numbers......Page 588 Summary......Page 615 Chapter 18: Unit Testing......Page 618 Getting Started with Unit Tests......Page 619 Writing Unit Tests with JUnit......Page 620 Exercise 1: Writing a First Unit Test......Page 623 Exercise 2: Writing a Successful Test......Page 627 Deciding What to Test......Page 629 Writing Parameterized Tests......Page 630 Exercise 3: Writing a Parameterized Test......Page 632 When Tests Won't Work – Disabling Tests......Page 634 Exercise 4: Using Test Setup and Cleanup Methods......Page 635 Testing with Mocks Using Mockito......Page 638 Exercise 5: Using Mocks when Testing......Page 641 Summary......Page 647 Chapter 19: Reflection......Page 650 Reflection Basics......Page 651 Exercise 1: Getting Class Information......Page 653 Determining Constructors......Page 661 Exercise 2: Extracting a List of Constructors......Page 662 Instantiating New Objects......Page 664 Exercise 3: Instantiating Objects......Page 665 Exercise 4: Extracting Method Information......Page 667 Calling Methods......Page 670 Exercise 5: Calling Methods......Page 671 Getting Fields......Page 673 Exercise 6: Getting Field Information......Page 674 Setting Field Values......Page 675 Reflection in the Real World – Dependency Injection......Page 677 Exercise 7: Using Dependency Injection......Page 679 Reflection in the Real World – JSON Data and RESTful Services......Page 681 Using the Jackson Library......Page 683 Exercise 8: Converting JSON Data Using Jackson......Page 685 Activity 1: Take-Out Food Delivery Using Drones and JSON......Page 692 Summary......Page 694 Chapter 20: Optionals......Page 696 Instantiating Optional Objects......Page 697 Getting Values......Page 699 The Presence Actions......Page 703 Exercise 1: Create Your Own Class Using Optionals......Page 705 map versus flatMap......Page 710 Returning with filter......Page 712 Activity 1: Experimenting with Filters......Page 714 Chaining Optionals to the Stream......Page 715 Summary......Page 717 Chapter 21: References......Page 720 Java Memory Management......Page 721 Strong References......Page 722 Weak References......Page 723 Exercise 1: Weak References......Page 724 Reference Queues......Page 729 Exercise 2: Creating a Shopping Cart......Page 730 WeakHashMap......Page 734 Exercise 3: WeakHashMap......Page 735 Activity 3: Solving the Memory Problem......Page 738 Exercise 4: Soft References......Page 739 Exercise 5: Phantom Reference......Page 742 Summary......Page 752 Chapter 22: Concurrent Tasks......Page 754 Thread Class versus Runnable Interfaces......Page 755 Some Thread Properties......Page 758 Activity 1 – Prioritize Tasks......Page 763 Sleep, Join, Interrupt......Page 765 Shared Resources......Page 773 Synchronized......Page 774 Exercise 1: Making a Thread That Counts and Discounts......Page 775 Atomic Variables/Operations......Page 784 Thread Pools......Page 788 Activity 2 – Random Amounts of Tasks......Page 793 Actor Model......Page 794 Summary......Page 795 Chapter 23: Using the Future API......Page 798 Futures......Page 799 The Executor Interface......Page 800 Employing the Thread Pool......Page 802 Exercise 1: Implementing Bubble Sort......Page 803 Exercise 2: Implementing Merge Sort......Page 810 Activity 2: Improving the MergeSort algorithm......Page 819 Working with Futures......Page 820 Exercise 3: Comparing Merge and Bubble Sorts......Page 821 Scheduling Futures......Page 839 Summary......Page 840 Appendix......Page 842 Index......Page 948