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

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