我怎样才能在Java中扩展函数而不是整个类？

Question

我怎样才能在Java中扩展函数？(不是课程延伸)

/*Example: 
 * year 1990 Alex Kumar 
 * year 1990 Jhon Ya'ay 
 * made this: do not touch modify here */
public static void OldMade()
{
    Connect("+1800PIZZA");        
    Say("MYID:69"); 
    Request("PIZZACITROEN_BLACK");
}

/*Example: 
 * year 2011 Sunil Williams
 * applied which extends 1990 */
public static void MadeInIndia extends this.OldMade
{
    //hidden include Connect("+1800PIZZA");        
    //hidden include Say("MYID:69"); 
    //hidden include Request("PIZZACITROEN_BLACK");
    Send("CorrectionPandit"); 
}

private static void main(Strig args[])
{
    // Try 1 call and get old + new
    MadeInIndia();        

    //execute  Connect("+1800PIZZA");        
    //execute  Say("MYID:69"); 
    //execute  Request("PIZZACITROEN_BLACK"); 
    //execute  Send("CorrectionPandit");
}

Answer 1

无法做到.Java的面向对象; 您只能从类和接口继承和扩展.

您没有"扩展"静态方法.在下面的安排中,B类的静态版本的foo将掩盖A中的那个.如果B需要调用A的静态方法,它可以明确地这样做:

public class A {

    public static void foo() { System.out("foo for A classes"); }
}

public class B extends A {

    public static void foo() { System.out("foo for B classes"); }
}