Java

James Gosling

• James Gosling is generally credited as the inventor of the Java programming language

• He was the first designer of Java and implemented its original compiler and virtual machine

• He is also known as the Father of Java

• He is currently the Chief Technical Officer of Sun Microsystems

• Gosling left Sun Microsystems which had been acquired by the Oracle Corporation in April

What is Java?

A multi-platform, network-centric, object-oriented programming language

– Multi-platform • It can run on almost any computer platform

– Network-centric• Designed with network in mind – “the network is the

computer”

• Designed for building applications for the Internet

– Object-oriented • It incorporates object-oriented programming model

Java Platform Editions

A Java Platform is the set of APIs, class libraries, and other programs used in developing Java programs for specific applications

There are 4 Java Platform Editions

1. Java Cards –For Smart Card2. Java 2 Platform, Standard Edition (J2SE)

• Core Java Platform targeting applications running on workstations3. Java 2 Platform, Enterprise Edition (J2EE)

• Component-based approach to developing distributed, multi-tier enterprise applications

4. Java 2 Platform, Micro Edition (J2ME)• Targeted at small, stand-alone or connectable consumer and embedded

devices

Basic Example•The User opens his web browser (the Client).

•The User browses to http://google.com.•The Client (on the behalf of the User), sends a request to http://google.com (the Server), for their home page.•The Server then acknowledges the request, and replies the client with some meta-data (called headers), followed

by the page's source.•The Client then receives the page's source, and renders

it into a human viewable website.•The User types Stack Overflow into the search bar,

and presses Enter

•The Client submits that data to the Server.•The Server processes that data, and replies with a page

matching the search results.•The Client, once again, renders that page for the User

to view.

ProgrammingServer-side Programming

Server-side programming, is the general name for the kinds of programs which are run on the

Server.Uses

•Process user input.•Display pages.

•Structure web applications.•Interact with permanent storage (SQL, files).

Examples•JSP, JQuery

Client-side programmingMuch like the server-side, Client-side programming is the name for all of the programs which are run on

the Client.Uses

•Make interactive webpages.•Make stuff happen dynamically on the web page.•Interact with temporary storage, and local storage

(Cookies, localStorage).•Send requests to the server, and retrieve data from

it.Example languages•JavaScript (primarily)

•HTML•CSS

FRONT END DEVELOPERCore Java, J2EE, HTML, JavaScript, XML, JSON, Putty, PHP, CSS, AJAX, JSON, Struts Frame work, JDBCCLIENT END DEVELOPERJQuery, UI, JSPSERVER END DEVELOPERJava concurrency and multithreadingBACK END DEVELOPEREclipse, JDeveloper, SOAP, REST, Maven, SVN, Sprint Tool Suite

Key Benefits & Features of Java

• Write Once, Run Anywhere– Java is portable and platform independent

• Network-centric– Can work with resources across a network and multi-tier architectures

• Object-oriented– A Java program models a set of objects interacting with each other

• Robust– Strong type checking– Exception handling mechanism– Automatic memory management

• Multithreaded– A Java application can run several different processes called “threads”

simultaneously

• Security– Can download remote code over a network and run it in a secure environment– Security levels and restrictions are highly configurable