1. Java environment
in 1999 released the second generation java platform referred Java2
Standard Edition Standard Edition J2SE
Enterprise Edition Enterprise Edition J2EE
miniature version of the Micro Edition J2ME
features
cross-platform
object-oriented
simplicity optimized C ++ multiple inheritance pointers
robust garbage collection, exception handling
multithreading
big data related development
The JVM
the Java Virtual Machine is not cross-platform virtual machine
memory space to open up the source file is compiled byte code
computer only recognize two 01 hardware, electricity, no power
source files .java .class bytecode
The JRE
the Java Runtime Environment Operating Environment Operating bytecode class contains the JVM
the Java program to run someone else written
JDK
tools need time to develop packages of Java Development Kit includes the JRE included JVM development tools
Install the development environment
installed JDK
official website www.oracle.com
install JDK do not need to repeat the installation JRE can skip
environment variable configuration
JAVA_HOME jdk installation directory
Path% JAVA_HOME% \ bin% JAVA_HOME % \ jre
javac.exe compilation tools
java.exe enforcement tools
run in the bottom of the doc command
bin folder tools
include folder contains another language native modifier
jre contains runtime environment
lib contains all the java class people written
src.zip compressed files java source code