使用封装继承多态编写，调用不同的打印机打印

[{"title":"（ 6 个子文件 2KB ） 使用封装继承多态编写，调用不同的打印机打印","children":[{"title":"打印机","children":[{"title":"ZTest.java <span style='color:#111;'> 414B </span>","children":null,"spread":false},{"title":"ZMaster.java <span style='color:#111;'> 350B </span>","children":null,"spread":false},{"title":"ZInkpetPrinter.java <span style='color:#111;'> 287B </span>","children":null,"spread":false},{"title":"ZDotMatrixPrinter.java <span style='color:#111;'> 284B </span>","children":null,"spread":false},{"title":"ZPrinter.java <span style='color:#111;'> 184B </span>","children":null,"spread":false},{"title":"ZLaserPrinter.java <span style='color:#111;'> 289B </span>","children":null,"spread":false}],"spread":true}],"spread":true}]