JavaTM is a new computer technology that is built in power-based network and the same software should run on a different computer system. These computer systems include consumer devices and other devices. With Java technology, you can convincing the same application in a wide variety of machines such as: PC, Macintosh systems, computer networks, or new technologies like Internet Visual phones.
Java can be used as a real programming language, or it can be seen as a complete platform. As a programming language, it is simple, object-oriented, safe, strong, and applicable to Internet technology. As a platform, it is available through applications developed by the standard APIs issued by Sun, in the operating system, database, middleware, and other third-party manufacturers.
What can you do with JAVA?
Java can make more flexible than other languages. The following is some typical applications of Java.
GUI Application and Applets Distributed Components (EJB, RMI, CORBA, etc.) databases and database control web server consumer equipment and built-in devices (mobile phones, PDAS, SMART cards, portable cameras) Any application you can think of on your computer ......
How does Java work?
The Java application can be translated by JVM (Java Virtual Machines), and JVM is located above the operating system. Many manufacturers have JVMS, such as Sun, IBM, HP, Applet, and more.
The following graph shows that Java is compiled and runtime steps:
Figure 1: Compilation of Java
Figure 2: Java's operation
Java applications (.class files) do not need to recompile to run on any operating system.
Here is a simple Java program:
Public class helloworld {public static void main (string args []) throws exception {system.out.println ("Hello World!");}}
A variety of Java products and APIs
The Java platform is divided into three main classes:
Standard Java Enterprise Java Java for Sonsumer and Embedded Devices
Below is some of the three applications of technologies / APIs.
Standard Java
Java 2 SDK (J2SE) Java 2 Running Environment JAVA Plug-in Java Web Apply Java Hotspot Service and Virtual Machine Java Basic Class (JFC) Collection Frame Swing Components Plug and Play Safety Java IDL JDBC Remote Method Call (RMI) Java 2D
Enterprise Java
Enterprise JavaBeans (EJB) architecture JavaServer Pages? (JSP) Java Servlet Java Naming and Directory Interface (JNDI) Java IDL JDBC Java Message Service (JMS) Java Transaction (JTA) Java Transaction Service (JTS) JavaMail RMI-IIOP Software Development Kit & Application Model Java 2 SDK, Enterprise Edition (J2EE) Sun BluePrints Design Guidelines for J2EE
Consumption and mobile devices
Java 2 Platform, Micro Edition (J2ME technology) Connected Device Configuration (CDC) Connected Limited Device Configuration (CLDC) C Virtual Machine (CVM) K Virtual Machine (KVM) PersonalJava Java Card JavaPhone API Java TV API Jini network technology Mobile Information Device ( MIDP)? Java's history
Since Java, Java has been introduced to the public in 1995, it has caused the public's attention. There are hundreds of valuable reports shortly: product release, narrative of Java technology. The following table roughly proves many critical events.
1995
Java technology released, the focus of the application is applets
1996
Java Development Kit (JDK) V1.0 is released. Component features of the core layer (socket programing, file i / o, gUI, etc.)
1997
JDK 1.1 is released. Introduce several enhancements: Java GUI, JDBC data control, RMI distribution objects and others.
1998
JDK 1.2 (called Java 2) Release JFC / Swing Ships, JFC / Swing has been downloaded more than 500,000 times
1999
Java technology is divided into J2SE, J2EE and J2ME Java Hotspot Performance Engine Unveiled JavaServer Pages (JSP) technology public J2EE Platform Ships J2se Platform On Linux Ships
2000
JDK V1.3 Release Java Apis for XML SHIP J2EE Authorization to ATG, BEA Systems, Gemstone, Silverstream, and several other companies. Many sellers have received this. Java developer members rose to 1.5 million.
Growth of Java
Java is now running on desktop systems, servers, databases, smart cards, PDAs, Smart phones, set-top boxes, etc.
Numerous reasons for Java success
Wonderful programming language
There is no object-oriented high-level dynamic in a similar memory problem with C / C , unlike C / C / VB security for the Internet program design platform: a compiled computer, running Java everywhere to launch a public approach instead of Windows, MQ Series, Sybase DB Lisonous private technologies such as library. This is very great for everyone, whether you are a developer or a business.
Some interested facts
In JavaOne 2000, more than 25,000 people participated; more than 330 companies showed their Java-based solutions in the world with over 2.5 million Java programs. IDC estimates that more than 4 million JDK V 1.1 will have more than 5 million downloads of the Java platform, more than 1,500 Java User Training (JUGS) SUN Solve Issues I have exceeded the website. 2,800, and more than 2,100 Java served 20 million Java Smartcards have been sold last year. Java.sun.com has 1.1 million viewers in this month, and they browse 36 million pages at this site. 80% of overseas universities require learning Java; 50% of them are compulsory courses
Key reasons are Java to add market judgment capabilities.
There is a large number of good products in the market to allow developers and developers to perform their system changes to be combined with a wide range of environments (due to support, XML, CORBA, etc.). Since being launched, Java has a mature maturity since being launched.
Java is Microsoft with its related technology
Sun and Microsoft disputes are irrelevant to developers, because you can simply install the Java virtual machine on Windows 2000, NT4.2, or 9x. For the Java of the browser, these items include:
Based on HTML / JavaScript web applications and server-side Java in IE 4.x and IE 5.x For JAVA 2 and updated version of Java 2 and updated version of the Java Web Start (in Browse) Outside of the device can also run applications) Java believes that under other UNIX platforms are better and faster than in the Windows platform. Several "bridge" can be used between Java and Microsoft technology
Xml
Java and XML are high-end supplement technology Java provides code layout, XML Provides data layout Java has mature support XML, XSL, and other related technologies in Java contains Sun, IBM, and Apache for XML program JSP as dynamic networks Can use XML
Others: WAP, SOAP, Bluetooth, CORBA, etc.
Java can be seen as a programming language or an angle of the entire platform from programming language
Java can meet almost so-write programs, many new technologies and products support Java interface Java can also expand through C / C .
