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![HelloWorld.java public class HelloWorld {! ! public static void main(String[] args){ System.out.println(“Hello World”);! }! }! In Java, you start with creaSng a class. Our class is called HelloWorld. A class can have methods. In this case it’s called main() You can run the class as a program if it has a method with the following signature public static void main(String[] args)! (c) Yakov Fain 2014 !](https://image.slidesharecdn.com/unit1-140204105023-phpapp01/75/Java-Intro-Unit1-Hello-World-11-2048.jpg)
![Homework 1. Write a program that will print your name and address in the Console view of Eclipse, for example: Alex Johnson 23 Main Street import java.uSl.Scanner; New York, NY 10001 public class FriendsAndFamily { USA public staSc void main(String[] args) { 2. Study all materials from Scanner input= new Scanner(System.in); Lesson 1 and 2 from the textbook do { System.out.println("n Enter list price: " ); double listPrice = input.nextDouble(); 3. Create a new project in Eclipse called Sale System.out.println(" Enter discount %: " ); int discount = input.nextInt(); 4. Enter, compile, and run the System.out.prinY(" You'll pay only $%2.2f", listPrice – program FriendsAndFamily. Try to guess, how this program works. listPrice*discount/100); } while (true); } 5. Study Eclipse tutorial at } hRp://bit.ly/EJSCx (c) Yakov Fain 2014](https://image.slidesharecdn.com/unit1-140204105023-phpapp01/75/Java-Intro-Unit1-Hello-World-17-2048.jpg)
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Java Intro: Unit1. Hello World
This document is a training guide for beginners learning Java programming using Eclipse IDE, referencing the textbook 'Java Programming 24-Hour Trainer' by Yakov Fain. It outlines the importance of Java, installation steps for JDK and JRE, and provides a walkthrough for creating and running a basic Java program. Additionally, it covers the features of Eclipse IDE and includes homework assignments to practice programming skills.
Java Intro: Unit1. Hello World
- 1. Java Programming Unit 1 Your first Java Program Eclipse IDE (c) Yakov Fain 2014
- 2. During this training course we’ll use the textbook “Java Programming 24-‐ Hour Trainer” by Yakov Fain. (c) Yakov Fain 2014
- 3. Why Learn Java? • Large code base of already wriRen applicaSons • 9 million of professional Java developers • Lots of enterprise applicaSons were developed and are being developed in Java • As per Tiobe index hRp://bit.ly/rItE Java remains one of the most popular languages. • The same program can run on different plaYorms • Mobile Android development is done in Java (c) Yakov Fain 2014
- 4. JDK and JRE • Java Development Kit (JDK) is required to develop and run programs • Java RunSme Environment (JRE) is required to run programs. • Users must have JRE installed, developers – JDK • JDK includes JRE (c) Yakov Fain 2014
- 5. Java SE and Java EE • Java SE: Java Standard EdiSon • Java EE: Java Enterprise EdiSon (formerly J2EE) • Java EE includes a set of technologies built on top of Java SE: Servlets, JSP, JSF, EJB, JMS, et al. • All Java programs run inside the Java Virtual Machine (JVM) (c) Yakov Fain 2014
- 6. Installing JDK on Windows Just press the buRons Next or ConSnue to complete the install. The at the end, JavaFX 2 will be also installed, which won’t be covered in this training. (c) Yakov Fain 2014
- 7. TesSng the installaSon • Add the bin folder to the PATH system variable of your computer (for details see hRp://java.com/en/download/help/path.xml). • Make sure that the newly installed version is being used. Open Command (or Terminal on MAC) window and type the following: java -‐version (c) Yakov Fain 2014
- 8. Walkthrough 1 1. Download Java SE 7 (Currently JDK 7 u51 – update 51 from hRp://www.oracle.com/technetwork/java/javase/downloads Download JDK, not JRE. In Windows, download the X86 version of Java. 2. Install Java SE (for details, see Lesson 1 of the textbook). To install Java SE 7 on MAC computers download the JDK dmg file from hRp://jdk7.java.net/download.html , run it and follow the instrucSons. 3. If amer typing java –version in the Command window (Terminal window on MAC OS)-‐ the reported version should be 1.7…. If not, you may need to modify the system variable PATH to include the bin directory of JDK. JDK 8 will be released in March of 2014. (c) Yakov Fain 2014
- 9. Three steps to run the Java program • Write the program and save it in a file with the name that ends with .java, for example HelloWorld.java • Compile the program using javac compiler, e.g. javac HelloWorld.java This will create a file HelloWorld.class • Run your program: java HelloWorld (c) Yakov Fain 2014
- 10. Compiling and running HelloWorld (c) Yakov Fain 2014
- 11. HelloWorld.java public classHelloWorld {! ! public static void main(String[] args){ System.out.println(“Hello World”);! }! }! In Java, you start with creaSng a class. Our class is called HelloWorld. A class can have methods. In this case it’s called main() You can run the class as a program if it has a method with the following signature public static void main(String[] args)! (c) Yakov Fain 2014 !
- 12. Walkthrough 2 • Create a directory called Prac-calJava and a subdirectory Lesson1. • Open a plain text editor, e.g. Notepad, enter the text of the HelloWorld program from previous slidw and save it as HelloWorld.java in the directory Lesson1. • Open the command window, change the directory to Lesson1 using the cd command. • Compile (javac) and run (java) HelloWorld program – it has to print HelloWorld on the screen. (c) Yakov Fain 2014
- 13. Eclipse IDE • Integrated Development Environment (IDE) makes your work more producSve • Includes text editor, compiler, debugger, context-‐ sensiSve help, works with different Java SDKs • Eclipse is the most widely used IDE • AlternaSves: IntelliJ IDEA (JetBrains), NetBeans (Oracle) (c) Yakov Fain 2014
- 14. (c) Yakov Fain 2014
- 15. Eclipse IDE • Eclipse for Java EE Developers comes with a number of plugins that will be used in second half of this course. • The latest version of Eclipse IDE is called Kepler. • Eclipse is also a plaYorm for plugin development – addiSonal features simplifying programming. (c) Yakov Fain 2014
- 16. Walkthrough 3 • Download and install the latest Eclipse for Java EE (32 Bit version) from hRp://www.eclipse.org/downloads. To install Eclipse simply unzip the content of the archive file you downloaded. To start Eclipse, double-‐click on Eclipse.exe (or Eclipse.app on MAC). • Create a new Java project named Hello by using the menu File | New (see Lesson 2 in the textbook for details). • Create a new Java class named HelloWorld and enter the code from LisSng 1-‐1 of the textbook. • Press Control-‐S to save and compile the code . • Run the program – right-‐click on HelloWorld and select the Run As menu item. (c) Yakov Fain 2014
- 17. Homework 1. Write a program that will print your name and address in the Console view of Eclipse, for example: Alex Johnson 23 Main Street import java.uSl.Scanner; New York, NY 10001 public class FriendsAndFamily { USA public staSc void main(String[] args) { 2. Study all materials from Scanner input= new Scanner(System.in); Lesson 1 and 2 from the textbook do { System.out.println("n Enter list price: " ); double listPrice = input.nextDouble(); 3. Create a new project in Eclipse called Sale System.out.println(" Enter discount %: " ); int discount = input.nextInt(); 4. Enter, compile, and run the System.out.prinY(" You'll pay only $%2.2f", listPrice – program FriendsAndFamily. Try to guess, how this program works. listPrice*discount/100); } while (true); } 5. Study Eclipse tutorial at } hRp://bit.ly/EJSCx (c) Yakov Fain 2014
- 18. AddiSonal Read • How to study online (the original, in Russian): hRp://www.stratoplan.ru/lib/break-‐the-‐ice/ The English translaSon done by Google Translate: hRp://bit.ly/10LXgrH • Eclipse IDE Workbench User Guide: hRp://help.eclipse.org/kepler/index.jsp (c) Yakov Fain 2014