JAVA program How to copy a directory of files and subdirectories to another directory, how to obtain system environment variables ... __java

Package test;

Import Java.io.BufferedReader;

Import java.io.IOException;

Import Java.io.InputStreamReader;

public class Test {

/**

* @param args

*/

public static void Main (string[] args) {

try {

Copy the directory and all the files and subdirectories under it

Runtime.getruntime (). EXEC ("xcopy c://aaa e://dd/s/e");

Get Windows System Environment variables

Process p = runtime.getruntime ()

. EXEC ("cmd.exe/c echo%java_home%");

BufferedReader br = new BufferedReader (new InputStreamReader p

. getInputStream ());

System.out.println (Br.readline ());

Setting Windows System Environment variables

Runtime.getruntime (). EXEC ("cmd.exe/c set aa=c://;");

/**

* Description of Key correlation value

* Java.version Java Version number

* Java.vendor java specified vendor string

* java.vendor.url Java Vendor URL

* Java.home Java installation directory

* Java.class.version Java class format version number

* Java.class.path Java Classpath

* Os.name Operating system name

* Os.arch Operating system structure

* Os.version Operating system version

* File.separator File Separator (on UNIX as "/")

* Path.separator Path Separator (on UNIX is ":")

* Line.separator line break (on UNIX is "/n")

* User.Name User account name

* User.home User Home Directory

* User.dir User's current working directory

* Wait a minute ...

*/

Get System Properties

System.out.println (System.getproperty ("Java.class.path"));

catch (IOException e) {

E.printstacktrace ();

}

}

}