abstract classPrinter{void open(){System.out.println("open");}void close(){System.out.println("close");} abstract void print();}//该打印机为喷墨打印机classHPPrinter extends Printer{void print(){System.out.println("使用喷墨打印机打印");}}//该打印机为针式打印机classCanonPrinter extends Printer{void print(){System.out.println("使用针式打印机");}}classTest{publicstaticvoid main(String args []){Printer p1 =newHPPrinter(); p1.open(); p1.print(); p1.close();Printer p2 =newCanonPrinter(); p2.open(); p2.print(); p2.close();}}原文：http://www.cnblogs.com/arroneve/p/5815449.html