Setting and HelloWorld of Java environment variables in 00003_win7

1. Setting of environment variables

(1) Open "Computer" → "System Properties" → "Advanced System Properties" → "Environment variables";

　　

(2) NEW:java_home: JDK installation path (e.g.,C:\Tools\Java\jdk1.7.0_51);

　　

(3) Path: add %java_home%\bin;;

　　

(4) Press the ALT key to display the toolbar, click "Tools" → "Folder Options" → "view" → Remove the "hide extensions of known file types" in front of the check box, so that the file suffix name can be displayed;

　　

(5) Windows logo key, hereafter referred to as win key;

　　

(6) Press and hold win+r at the same time, input cmd, enter the DOS command line interface;

　　

(7) In the DOS interface input java,javac,java-version,javac-veriosn are tested successfully, wherein java-version ,javac-veriosn pop-up interface such as:

　　

　　

2. Writing Helloworld.java files

(1) Create a new text document and enter the following code

Class helloworld{2     void main (string[] args) {3 System.out.println ("helloworld! I love Java"  ); }5}       

(2) Save to D disk D:\Java\00Base\01day folder, file name is Helloworld.java, save type " All Files ", encoded as ANSI ;

　　

(3) switch to the folder where Helloworld.java is saved (for example,D:\Java\00Base\01day);

　　　　①d: yes switch to D drive;

②cd D:\Java\00Base\01day is the switch to D:\Java\00Base\01day folder;

③javac helloworld.java compile helloworld.class file;

④Java HelloWorld run the helloworld.class file.

　　

(4) Write Java code using advanced Notepad notepad++.

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Setting and HelloWorld of Java environment variables in 00003_win7