問題：

定義寵物類，定義Dog,Cat 子類

定義主人類，實現和寵物類玩方法playwith(? )

在測試類中用子類實例調用主人類的playwith()方法

我·：1.接口

package?pa;

public?interface?Pet?{
????public?abstract?void?playwith();
}

2.Dog類

package?pa;

public?class?Dog?implements?Pet{

????@Override
????public?void?playwith()?{
System.out.println("The?onwer?is?playing?with?the?dog.");
????}
}

3.Cat類

package?pa;

public?class?Cat?implements?Pet{

????@Override
????public?void?playwith()?{
????????System.out.println("The?owner?is?playing?with?the?cat.");
????}
}

4.Owner類

package?pa;

public?class?Owner?{
????public?static?void?main(String[]?args)?{
????????Pet?pet?=new?Cat();
????????Pet.playwith();
????????Pet?pet?=new?Dog();
????????Pet.playwith();
????}
}

運行結果：

無法從靜態上下文中引用非靜態 方法 playwith()

已在方法 main(java.lang.String[])中定義了變量 pet