Java Getting Started learning

Want to learn java, first you have to understand what Java is, what it attracts, understand the program should know that Java is the root of many computer language, no matter in what era, technology updates, Java will not lag behind, now I am learning the primary java, Below to everybody also popularize some elementary knowledge!

A Common dos commands in Window

where to operate dos commands :

Win7---> start ----"all programs ---" accessories ----"command prompt

win7--> start ---"run ----" input cmd

1.1 The switch of the drive letter:

disk Fu Yi + colon format: drive letter :

example: want to from C Drive to D Drive

C:/user/xxxx D:

operation of the 1.2 folder

Dir : Displays all files and folders in the current Folder.

CD path : Enter to the specified path.

Cd.. : go back to the top level directory

CD \: back to the current directory with the directory

MD folder name create a folder

Rd Folder name Delete Folder Action

operation of the 1.3 file

echo data ( content ) > file name Create a file and specify the Data.

Type file name to view the contents of the specified file

del file name deletes the specified file

* wildcard characters

tab Fill Content

CLS Clear Screen

Up and down ARROW keys get back what you wrote last time

Exit Close the Console.

Java is divided into 3 versions:

1.JavaSE

2.javaEE---> j2e

3.javaME

One of the important features of Java :

Cross-platform ( operating system ) .

What is Cross-platform:

compile once and run Everywhere.

Is the Java virtual machine cross-platform ?

no cross-platform, just a transit point : allow this java instruction to be recognized by the operating System.

JVM (java Virtual machine, just for java Systems )

Java features two: open source

complete the first Java program :

1. A Java virtual machine is required .

Java Construction of the environment :

Jre:java the operating Environment. Jre = java virtual machine + Core class library ( files that are run by Auxiliary java ) ;

Jdk:java development tool set jdk = JRE + java Development tools

Install Jdk: be aware that there is no Chinese in the Directory.

Description of the JDK directory:

Development tools for bin:java

Db:jdk7 comes with a miniature database Derby

Include : The file that holds the calling system interface

Jre : java Runtime Environment

Lib : Core class Library

The source code of the Src.zip:java.

Development tools for Java

Javac.exe:java compiler to compile the source file into a . class file

Java.exe : The java file is running

questions: there is no way to work with files and tools Separately.

We hope : Locate the file directly and compile it via javac .

Path environment variable

How to configure path :

My Computer ---"right --" Properties ---"advanced system settings ---" Environment variables - -"system variables --"path---> edit ( double-click )

Locate The file directory where the Java development tools are located, copy the directory, paste it to The back of the path, and give it a semicolon after the win7 is finished pasting. ( english )

Java Getting Started learning