静态方法行为不具备多态性，直接访问某个域不是多态

如果某个方法是静态的，他的行为就不具多态性，静态方法是与类而非单个对象相关联。

public class A{


public static void main(String[] args) {
StaticFu sf = new Son();
System.out.println(sf.staticOut());
System.out.println(sf.out());
}
}






class StaticFu{
public static String staticOut() {
// TODO Auto-generated method stub
return "static  StaticFu";
}

public  String out() {
// TODO Auto-generated method stub
return "StaticFu";
}
}


class Son extends StaticFu{
public static String staticOut() {
// TODO Auto-generated method stub
return "static  Son";
}

public  String out() {
// TODO Auto-generated method stub
return "Son";
}
}

结果：

static  StaticFu
Son

域和多态

public class A{


public static void main(String[] args) {
Fu fu = new Son();
System.out.println("fu.filed = "+fu.field+",fu.getField="+fu.getField());
Son son = new Son();
System.out.println("son.filed = "+son.field+",son.getField="+son.getField()+",son.getSuperField()="+son.getSuperField());
}
}






class Fu{
public int field = 0;
public int getField() {
return field;
}
}


class Son extends Fu{
public int field=1;
@Override
public int getField() {
// TODO Auto-generated method stub
return field;
}
public int getSuperField(){
return super.field;
}
}

结果：

fu.filed = 0,fu.getField=1
son.filed = 1,son.getField=1,son.getSuperField()=0

想要得到父类中的field必须super.field