/**
 * @author lautturi.com 
 * Java example:get environment variable APPDATA path in java
 */
import java.util.*;
public class Lautturi {
	public static void main(String[] args) {
		String path = System.getenv("APPDATA");
		System.out.println(path);
	}
}
output:
C:\Users\Administrator\AppData\Roaming
ALLUSERSPROFILE ANDROID_HOME APPDATA COCOS_CONSOLE_ROOT COCOS_TEMPLATES_ROOT COCOS_X_ROOT CommonProgramFiles CommonProgramFiles(x86) CommonProgramW6432 COMPUTERNAME ComSpec DIRCMD DNX_HOME DOCKER_TOOLBOX_INSTALL_PATH FONTCONFIG_FILE HOMEDRIVE HOMEPATH JAVA_HOME JDK_HOME JRE_HOME LOCALAPPDATA LOGONSERVER LUA_DEV LUA_PATH MAGICK_HOME NODE_PATH NUMBER_OF_PROCESSORS OneDrive OS Path PATHEXT PROCESSOR_ARCHITECTURE PROCESSOR_IDENTIFIER PROCESSOR_LEVEL PROCESSOR_REVISION ProgramData ProgramFiles ProgramFiles(x86) ProgramW6432 PROMPT PSModulePath PUBLIC SESSIONNAME SystemDrive SystemRoot TEMP TESSDATA_PREFIX TMP USERDOMAIN USERDOMAIN_ROAMINGPROFILE USERNAME USERPROFILE