Java @Override 注解

Posted 2021-01-30 飞龙dragon

@Override注解,不是关键字,但可以当关键字使用,可以选择添加这个注解,在你不留心重载而并非复写了该方法时,编译器就会产生一条错误:The method doh(Milhouse) of type Bart must override or implement a supertype method

// reusing/hide.java
//owrloading a base method name in a derived
package object;

import static net.mindview.util.Print.*;

class Homer{
    char doh(char c)
    {
        print("doh(char)");
        
        return ‘d‘;
    }
    float doh(float f)
    {
        print("doh(float");
        return 1.f;
    }
}
class Milhouse{}
class Bart extends Homer{
    void doh(Milhouse m)
    {
        print("doh(Milhouse");
    }
    @Override char doh(char c) //基类必须也有char doh(char c)方法
    {
        print("I have not heavy load");
        return ‘a‘;
    }
}

public class Hide {
    public static void main(String[] args)
    {
        Bart b = new Bart();
        b.doh(1);
        b.doh(‘x‘);
        b.doh(1.0f);
        b.doh(new Milhouse());
    }
}/* output:
doh(float
I have not heavy load
doh(float
doh(Milhouse
*///~