Lesson: Object-Oriented Programming Concepts (The Java™ Tutorials > Learning the Java Language) If you've never used an object-oriented programming language before, you'll need to learn a few basic concepts before you can begin writing any code. This lesson will introduce you to objects, classes, inheritance, interfaces, and packages. Each discussion focuses on how these concepts relate to the real world, while simultaneously providing an introduction to the syntax of the Java programming language. What Is an Object? An object is a software bundle of related state and behavior. What Is a Class? A class is a blueprint or prototype from which objects are created. What Is Inheritance? Inheritance provides a powerful and natural mechanism for organizing and structuring your software. What Is an Interface? An interface is a contract between a class and the outside world. What Is a Package? A package is a namespace for organizing classes and interfaces in a logical manner. Questions and Exercises: Object-Oriented Programming Concepts
Java Serialization API Oracle Technology Network > Java Software Downloads View All Downloads Top Downloads New Downloads What's New Java in the Cloud: Rapidly develop and deploy Java business applications in the cloud. Essential Links Developer Spotlight Java EE—the Most Lightweight Enterprise Framework? Blogs Technologies Contact Us About Oracle Cloud Events Top Actions News Key Topics Oracle Integrated Cloud Applications & Platform Services
Java IDE--lIntelliJ IDEA. Java 8 & Java EE 7 Support Straightforward User Interface Editor New Features New Tools for Android Developers Refined Gradle Integration New Tools for Database Access IntelliJ IDEA 13.1, the Java IDE with the fastest-growing mindshare, includes support for Java 8 and Java EE 7, new tools for Android development, the editor enhancements, and refined Gradle integration. IntelliJ IDEA 13 adopts Java 8 and Java EE 7, the latest versions of Oracle's Java language and enterprise platform, along with support for new versions of enterprise application servers. The new editor comes with Sublime Text style multiple selections and also introduces Postfix code completion, a new kind of completion for Java which extends your productivity even more. IntelliJ IDEA 13.1, the Java IDE with the fastest-growing mindshare, includes enhanced support for Java EE 7, better Spring support, new tools for Android development and refined Gradle integration.
Using Package Members (The Java™ Tutorials > Learning the Java Language > Packages) The types that comprise a package are known as the package members. To use a public package member from outside its package, you must do one of the following: Refer to the member by its fully qualified nameImport the package memberImport the member's entire package Each is appropriate for different situations, as explained in the sections that follow. Referring to a Package Member by Its Qualified Name So far, most of the examples in this tutorial have referred to types by their simple names, such as Rectangle and StackOfInts. However, if you are trying to use a member from a different package and that package has not been imported, you must use the member's fully qualified name, which includes the package name. You could use this qualified name to create an instance of graphics.Rectangle: graphics.Rectangle myRect = new graphics.Rectangle(); Qualified names are all right for infrequent use. Importing a Package Member import graphics.Rectangle; Rectangle myRectangle = new Rectangle();
Jikes' Home Java for C Programmers CSCI.4220 Network Programming Java for C Programmers This is a brief Java tutorial intended for people who are strong programmers in C++ and need to learn Java quickly. It was written for students in Network Programming, and so it emphasizes features of Java that will be needed for this course, but it should be useful for anyone. Structure of a java program Java is a more object oriented language than C++. All code is in a class. Typically, each class is defined in a separate file. This file is called HelloWorld.java public class HelloWorld { public static void main(String args[]) { System.out.println("Hello World!") It defines a class called HelloWorld (Note that java is case sensitive). The line System.out.println("Hello World!") Everything else should be self-explanatory. The java compiler is javac. Java programs are not directly executed. The Java Development Kit 1.5.0 (JDK) which includes the compiler and the run time environment is available on the CS department systems. Student.java
Using Objects (The Java™ Tutorials > Learning the Java Language > Classes and Objects) Once you've created an object, you probably want to use it for something. You may need to use the value of one of its fields, change one of its fields, or call one of its methods to perform an action. Referencing an Object's Fields Object fields are accessed by their name. You must use a name that is unambiguous. You may use a simple name for a field within its own class. System.out.println("Width and height are: " + width + ", " + height); In this case, width and height are simple names. Code that is outside the object's class must use an object reference or expression, followed by the dot (.) operator, followed by a simple field name, as in: objectReference.fieldName For example, the code in the CreateObjectDemo class is outside the code for the Rectangle class. System.out.println("Width of rectOne: " + rectOne.width); System.out.println("Height of rectOne: " + rectOne.height); Later, the program uses similar code to display information about rectTwo. int height = new Rectangle().height; or:
"Hello World!" for Microsoft Windows (The Java™ Tutorials > Getting Started > The "Hello World!" Application) It's time to write your first application! The following instructions are for users of Windows XP Professional, Windows XP Home, Windows Server 2003, Windows 2000 Professional, and Windows Vista. Instructions for other platforms are in "Hello World!" for Solaris OS and Linux and "Hello World!" for the NetBeans IDE. If you encounter problems with the instructions on this page, consult the Common Problems (and Their Solutions). A Checklist To write your first program, you'll need: The Java SE Development Kit 8 (JDK 8)You can download the Windows version now. These two items are all you'll need to write your first application. Creating Your First Application Your first application, HelloWorldApp, will simply display the greeting "Hello world!". Create a source fileA source file contains code, written in the Java programming language, that you and other programmers can understand. Create a Source File To create a source file, you have two options: First, start your editor. Be Careful When You Type
The Java Community Process(SM) Program - JSRs: Java Specificatio Status: Dormant JCP version in use: 2.6 Java Specification Participation Agreement version in use: 2.0 Description: Groovy is an agile, dynamic programming language for the Java Virtual Machine. Groovy includes features found in Python, Ruby, and Smalltalk, but uses syntax similar to the Java programming language. Please direct comments on this JSR to the Spec Lead(s) This JSR has been Dormant Reason: The Specification Lead chose to list this JSR as dormant in April 2012. Updates to the Original JSR The following information has been updated from the original proposal. Specification Lead: VMWare E-Mail Address: glaforgevmware.com Telephone Number: - Fax Number: - 2.2 What is the target Java platform? Java 2 Platform, Standard Edition 5, and subsequent versions of Java SE. 2.3 The Executive Committees would like to ensure JSR submitters think about how their proposed technology relates to all of the Java platform editions. 2.6 Why isn't this need met by existing specifications? Section 1. No and