Hands-On Object-Oriented Programming with Kotlinby Abid Khan and Igor Kucherenko. The main purpose of the book is to provide a comprehensive coverage of Kotlin features such as classes, data classes, and inheritance. It also provides a good understanding of design pattern and how Kotlin syntax works with object-oriented techniques.

With Kotlin, you can intermix imperative, functional, and object-oriented styles of programming and benefit from the approach that’s most suitable for the problem at hand. Learn to use the many features of this highly concise, fluent, elegant, and expressive statically typed language with easy-to-understand examples. Learn to write maintainable, high-performing JVM and Android applications, create DSLs, program asynchronously, and much more.

This is a main idea of any object-oriented programming language – the classes and objects are the first-class citizens. In this chapter I’ll focus on discussing how you can program behavior in Java. Classes have attributes (e.g. color, number of doors) and exhibit behavior (e.g. eat, sleep, java книги or dive). There is a special group of programming languages that are called functional (e.g. JavaScript, Scala et al). In these languages you can simply write functions like eat, sleep, or dive, and these functions can live their independent lives and don’t have to be declared in classes.

JavaFX has more than 60 GUI components, so try to play with them. Also, JavaFX allows you to integrate audio and video in your application, create special effects and transitions to make your programs as cool and entertaining as you want them to be. You may find some interesting capabilities by researching classes located in the package javafx.animation. In Scene Builder you may have noticed the Controller bar in the bottom left corner. This is the place were you can specify a Java class that will contain event handling code and may use other classes implementing application logic.

6. Project: Adding Events Handling For Calculator

Mastering Android Development with Kotlinbegins by giving you a strong grasp of Kotlin’s features in the context of Android development and its APIs. Moving on, you’ll take steps toward building stunning applications for Android. The book will show you how to set up the environment, and the difficulty level will grow steadily with the applications covered in the upcoming chapters. Later on, the book will introduce you to the Android Studio IDE, which plays an integral role in Android development.

The most popular are Eclipse, NetBeans, and IntelliJ IDEA. In this book we’ll use IntelliJ IDEA Community Edition. This is an excellent IDE for developing Java applications, and if you decide to program later on in other programming languages, IDEA supports more than a dozen other languages too.

The code that comes with the book has this version of the method updateScore implemented. Your goal is to display the score in a nice font on the bottom left java книги corner of the table. you can learn how to work with the Text and Font classes by studying Oracle’s tutorial “Working with Text in JavaFX Applications”.

java книги

The addition of modules by JDK 9 represents one of the most profound changes ever made to the Java language. For example, it resulted in the addition of 10 context-sensitive keywords. Modules also significantly impacted the Java API library because its packages are now organized into modules. Furthermore, to support modules, new tools have been added, existing tools have been updated, and a new file format has been defined.

In object-oriented languages behavior is implemented in methods defined in classes. A simple project like our HelloWorld will have just one file with the source code More advanced projects will consist of multiple files. To simplify the application deployment, all these files could be packaged in one or more JARs too.

In this chapter we’ll establish a link between GUI and the controller. We’ll also add event handlers and will write code to modify the GUI. I’ll continue working with FXML samples created in the previous chapter, but this time the GUI events will be handled by the code from the controller class. Just create a new project (the menu File | New Project), select JavaFX application as the project type and give it a name. In a second new project will be created with two Java classes Main and Controller and a file named sample.fxml as shown below.

Both beginners and experienced professionals will find it quite useful. If you open the project directory with File Manager (or Finder), you’ll see that there are other folders that contain code samples for all of the chapters. You can open any of these projects in IDEA by selecting the menu File | Open. Note that this project directory has a folder named .git, which contains Git database with the history of all commits that I did while writing code samples for this book.

  • Later on, the book will introduce you to the Android Studio IDE, which plays an integral role in Android development.
  • Moving on, you’ll take steps toward building stunning applications for Android.
  • The book will show you how to set up the environment, and the difficulty level will grow steadily with the applications covered in the upcoming chapters.
  • Mastering Android Development with Kotlinbegins by giving you a strong grasp of Kotlin’s features in the context of Android development and its APIs.

You’ll always write event handlers (a.k.a. event listeners) in Java, but there are different ways of assigning event handlers to GUI elements. If your GUI is designed using FXML, you’ll need to specify the name of your controller class right in the FXML file. If your GUI is designed with Java, using a separate controller class is not a must, but is a good idea if your code has to process multiple events. In Chapters 7 and 8 I gave you a very brief introduction to JavaFX. You’ll be writing more of JavaFX code in chapters 9, 10, and 13, but JavaFX has lots of interesting features that you may want to explore on your own.

Supported libraries for serialization, regular expression and testing are also covered in this book. By the end of the book, you would learn building robust and maintainable software with object oriented design patterns in Kotlin. Although introduced in the previous edition of this book, there are two recently added Java features that are still having a strong impact on Java programmers. The first is modules, which enable you to specify the relationships and dependencies of the code that comprises an application.

We’ll also show you how to integrate Kotlin into any existing Android project. Kotlinby Mehmet Ali SICAK was created to introduce Kotlin to programmers. This book is the first and currently only Kotlin book in Turkish.

The reason you may want use the URLConnection class is that it could give you some additional control over the I/O process. For example, by calling its method setDoOutput with the argument true you enable WebSiteReader to write to the remote URL. In this case you’d java книги need to get a reference to an OutputStream object by calling getOutputStream method on the URLConnection object. If you wanted to write a program that can send data to the server, you’d need to learn server-side programming, which this book doesn’t cover.

The new version of the controller will use the @FXML annotations to inject the references to the GUI components. To update the position of the kid’s paddle on the GUI we’ll use data binding explained in Chapter 8. We’ll also add the method initialize that is invoked by the Java runtime once when the controller object is created. Finally, we’ll write the code in the methods process_key_Down and process_key_Up to move the kid’s paddle vertically. The Main class of a JavaFX application extends Application and is an entry point of your application.

It then takes you through reactive and concurrent patterns, teaching you about using streams, threads, and coroutines to write better code along the way. By the end of the book, you will be able to efficiently address common problems faced while developing applications and be comfortable working on scalable and maintainable projects of any size. Even Google has adopted it as a first-class language for Android development.

Head First Java

You can also open your .fxml file in the text editor and type in the name of the controller class there. If you’ll look at any of the FXML files from Chapter 7, you’ll see that the name of the controller was specified there when IDEA generated the project for us. When IDEA creates a new JavaFX project it generates an empty class Controller, which is the right place for the code that communicates with GUI components.

Hands-on Design Patterns with KotlinThe mission of this book is to ease the adoption of design patterns in Kotlin and provide good practices for programmers. The book begins by showing you the practical aspects of smarter coding in Kotlin, explaining the basic Kotlin syntax and the impact of design patterns. From there, the book provides an in-depth explanation of the classical design patterns of creational, structural, and behavioral families, before heading into functional programming.

Java comes with a jar utility that is used to archive multiple Java classes and other files into a file having the name extension .jar. If your IDEA project will have multiple classes, you can package them into one JAR by using the menu File | Project Structure | Artifacts and then selecting the type JAR. Most programmers write, compile and run their applications in special programs that go by the name Integrated Development Environment (IDE). Any IDE provides help as you type code, highlights the Java keywords, has a Help menu that describes all elements of the language, and makes it easier to find and fix errors in your programs. There are several excellent IDEs that are free to use.

When the method start is invoked, it’ll receive a reference to the Stage object – this is where your GUI components will live and perform. In this chapter I’ll explain the basics of GUI programming with JavaFX. You’ll learn how to create GUI containers and arrange GUI components inside them. In the next chapter you’ll learn how to write code that reacts on user’s actions (a.k.a. events) like a click of a button or a mouse move.

For example, a button click, the movement of the mouse etc. When the event happens, the event object is represented by one of the subclasses of the class Event located in the packages javafx.event and javafx.scene.input. You need to decide what events are important to your program and, as the programmers say, “listen to these events”.

1. Two Types Of Version Control Systems

Because of their importance, the entirety of Chapter 16 is devoted to modules. JShell is a tool that offers an interactive environment in which it is easy to experiment with code snippets without having to write an entire program.

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