New brother takes you into the Java World __java Learning

New brother from the recent comments we have noticed that the basic knowledge is more important, a lot of friends want to speak some of the knowledge of the introduction, in order to meet the needs of the development enthusiasts, new PA decided to start from the most basic, 1.1 points to help everyone into the world of cloud computing. The next new brother to lead the first start, today's first stop is to enter the Java world.


A friend who likes to program may know that Java is a very popular developer since Java can run on multiple platforms, such as Windows, Mac OS, and other UNIX versions of the system. Java has cross-platform features.


The father of Java


Java-loving friends should be more familiar with the father of Java, the father of Java----James Goslin was born in Canada, is a computer programming genius. While studying for a PhD in computer science at Mellon University, he wrote a multiprocessor version of the UNIX operating system, the founder of Java. Shortly after Oracle's acquisition of Sun in 10, the Java programming language inventor announced his departure and joined Google in early 11.


Java Origin and development

Java is a high-level programming language introduced by Sun Microsystems in May 1995. In 1991, during Sun's work, Gauss Forest and a group of technicians created a project called Oak designed to develop a programming language running on the VM while allowing programs to run on multiple platforms, such as TV set-top boxes. Later, the work evolved into Java. With the popularization of the Internet, especially the Web browser developed by Netscape, Java has become a popular development language in the world. October 24, 2010. Oracle, the US data software giant, announced 20th to buy sun for 7.4 billion dollars, ushering in a new period of development in Java.

Java Platform System


The new brother has noted that Java is divided into three systems Javase (JAVA2 Platform Standard Edition,java Platform Standard Edition), Java EE 2 platform,enterprise Edition, Java Platform Enterprise Edition), Javame (Java 2 Platform Micro Edition,java Platform Miniature Edition). Which j2se. It allows you to develop and deploy Java applications that are used in desktops, servers, embedded environments, and live environments. The Java SE contains classes that support Java WEB Service development and provides a foundation for Java platform,enterprise Edition (Java EE). Another important point is that Java EE is built on the basis of Java SE, which provides Web services, component models, management, and communication APIs that can be used to implement enterprise-class service-oriented architectures (service-oriented architecture, SOA) and Web 2.0 applications. Another thing that will be replaced is the Java ME provides a robust and flexible environment for applications running on mobile devices and embedded devices such as mobile phones, PDAs, TV set-top boxes, and printers. Now it's supposed to be Android on the mobile side, and Android is also developed in Java.


Java Development environment


For the novice programmer may not understand the process of Java compilation, which led to the Java run does not know what is going on, the following new brother will introduce you to the Java compilation run process. When we write Java source files (. java), we first compile and generate the so-called bytecode file (. Class). Java programs need to be run by the JVM to support the JVM is a software, installed in our computer operating system, for bytecode files to provide a running environment. One of the unique features of Java is that it is used everywhere, because Java officials provide JVM software for different platforms, but these JVMs have a certain standard, as long as the standard. class files can be run on different JVMs, and the effect is the same.


Java Environment Configuration


The first thing you need to know about Java development Environment configuration is the relationship between JDK, JRE, and JVM. The JDK is the Java Development Toolkit, the JRE is the Java Runtime Environment, and the JVM is the Java virtual machine. It is worth noting that the minimum environment required to run a Java program is the JRE, and the minimum environment required to develop a Java program is the JDK. The JRE is the JVM plus Java System Class Library, which consists of the JRE and the development tools such as compiling and running. In the configuration Java environment, you need to download the installation JDK first, then configure the environment variables, the configuration is complete after the Java program can be developed, if there are friends do not understand the direct contact with the new brother.


Java's basic knowledge is introduced here, if you are interested in Java development, welcome to join the new brother to study together, the back of the new brother will continue to bring more new technical introduction.