Basic Java Theory Learning a

The biggest advantage of Java is the cross-platform

Version and Architecture of Java

1.J2EE Java 2 Enterprise Edition positioning in server-side applications

2.J2SE Java 2 Standard Edition positioning on personal computer applications

3.j2me Java 2Micro Edition positioning in the application of consumer electronic products

The JDK contains the JVM contained in the JRE,JRE

JDK Java Development Kit Java Development Kit

JRE Java Runtime Environment Java run-time environment

JVM Java Virtual machine Java VM has IBM virtual machine, SUN, BEA and other virtual machines, can also write their own JVM

Java all software to www.oracle.com inside download

Latest version of Jdk:http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

After the JDK is installed, environment configuration is required and there are two steps

1.java_home:c:\program files\java\jdk1.7.0_79 (JDK installation directory)

2.path:%java_home%\bin, it could be C:\Program files\java\jdk1.7.0_79\bin.

Note: If you have multiple values for the same environment variable, separate them with semicolons

Successful JDK installation test

Open Cmd.exe, then enter Java, carriage return with menu display indicates success

Build a simple project output hello

1. In D: Build a txt, enter

public class Hello
{
public static void Main (string[] args)
{
System.out.println ("Hello");
}
}

The suffix is changed to Java, and the full name is Hello.java

2. Enter Javac D:hello.java return in CMD program

Generate a new file Hello.class

3. Enter Java Hello return in the CMD program

Output Hello

Complete

Operating principle: such as, combined with the above example is easy to read

Basic Java Theory Learning a