class SingleDemo { public static void main(String[] args) { for( int i=1;i<10;i++) { Thread t1 = new Test(); t1.start(); } } } class Test extends Thread { public void run() { Single single = Single.getInstance(); System.out.println( this.getName() + " getInstance:"+single); } } class Single { private static final Single SINGLE = new Single(); private Single(){} public static Single getInstance() { return SINGLE; } }