Java is an object-oriented programming language developed by James History . Java was started as a project called "Oak" by James Gosling in June The History and Evolution of Java. CHAPTER 2. An Overview of Java .. No discussion of Java's history is complete without a look at the Java buzzwords. Free kindle book and epub digitized and proofread by Project Gutenberg.
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Book digitized by Google and uploaded to the Internet Archive by user tpb. This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project to make the. Agenda. Brief History of Java and overview of language. Solve a problem to demonstrate Java syntax. Discuss coding issues and style via example scuss cod g.
Keep it Robust and Secure. Keep it architecture-neural and portable. Executable with High Performance. Interpreted, threaded and dynamic. Java 1. When Java 1.
This was not the condition when Java 1. The next number in sequence was 3, but calling Java 1. Places where Java is used Java is implemented over a number of places in modern world. Created by James Gosling. Language was created with 5 main goals: It should be object oriented "! A single representation of a program could be executed on multiple operating systems "! It should fully support network programming "!
It should execute code from remote sources securely "! It should be easy to use "! Oak was renamed Java in ! Applets "! Had early support from companies like Netscape Communications! As a product. The Budding Tree "! Java was publicly released May In general.
Java is defined by two entities: A platform Java Runtime Environment. JRE "! A language Java Software Development Kit.
SDK "! Java address traditional concerns with other programming languages like "! Security "! Reusability "! Transportability platform independence "!
Created and maintained by Sun Microsystems! The Java Platform "! The Java platform provides "! The run-time environment "! The necessary libraries platform libraries "! The Java platform is NOT platform independent "! Platforms exist for many Operating Systems "!
Such as: Platforms defined in terms of JVM and platform libraries "!
Platform Editions "! Java has different platform editions "! Java SE "! Complete environment for application execution " " " " "! Stand-alone server applications! Stand-alone client applications!
Stand-alone client-server applications!
This is called an access level modifier. Other access level modifiers include the keywords private and protected. The keyword static  in front of a method indicates a static method , which is associated only with the class and not with any specific instance of that class.
Only static methods can be invoked without a reference to an object. Static methods cannot access any class members that are not also static. Methods that are not designated static are instance methods and require a specific instance of a class to operate. The keyword void indicates that the main method does not return any value to the caller.
If a Java program is to exit with an error code, it must call System. The method name main is not a keyword in the Java language. It is simply the name of the method the Java launcher calls to pass control to the program. Java classes that run in managed environments such as applets and Enterprise JavaBeans do not use or need a main method.
A Java program may contain multiple classes that have main methods, which means that the VM needs to be explicitly told which class to launch from. The main method must accept an array of String objects.
By convention, it is referenced as args although any other legal identifier name can be used. The effect of this alternate declaration is semantically identical to the args parameter which is still an array of String objects , but it allows an alternative syntax for creating and passing the array. The Java launcher launches Java by loading a given class specified on the command line or as an attribute in a JAR and starting its public static void main String method.
Stand-alone programs must declare this method explicitly. The String args parameter is an array of String objects containing any arguments passed to the class.
The parameters to main are often passed by means of a command line. Printing is part of a Java standard library: The System class defines a public static field called out.
The out object is an instance of the PrintStream class and provides many methods for printing data to standard out , including println String which also appends a new line to the passed string.