System类

public static void main(String[] args) {

String osName = System.getProperty("os.name");
String user = System.getProperty("user.name");
System.out.println("当前操作系统是："+osName);
System.out.println("当前用户是："+user);
System.out.println(System.getProperty("os.arch"));
System.out.println(System.getProperty("java.version"));
System.out.println(System.getProperty("java.vendor"));//供应商  Inc.incorporated 责任有限公司
System.out.println(System.getProperty("java.vendor.url"));
System.out.println(System.getProperty("java.home"));
System.out.println(System.getProperty("java.vm.specification.version"));
System.out.println(System.getProperty("java.vm.specification.vendor"));
System.out.println(System.getProperty("java.vm.specification.name")); //specification 规范
System.out.println(System.getProperty("java.vm.name"));
System.out.println(System.getProperty("java.class.path"));
System.out.println(System.getProperty("java.library.path"));
System.out.println(System.getProperty("java.compiler"));
System.out.println(System.getProperty("os.version"));
System.out.println(System.getProperty("file.separator"));
System.out.println(System.getProperty("path.separator"));
System.out.println(System.getProperty("line.separator"));
System.out.println(System.getProperty("user.dir"));
System.out.println(System.currentTimeMillis());
System.gc();
System.exit(0);
}