public class StaticDispatch {
static abstract class Human {}
static class Man extends Human{}
static class Woman extends Human{}
public void sayHello(Human guy) {
System.out.println("hello, guy");
}
public void sayHello(Man guy) {
System.out.println("hello, gentleman");
}
public void sayHello(Woman guy) {
System.out.println("hello, lady");
}
public static void main(String[] args) {
Human man = new Man();
Human woman = new Woman();
StaticDispatch sr = new StaticDispatch();
sr.sayHello(man);//hello, guy
sr.sayHello(woman);//hello, lady
}
}
运行时多态
运行期间决定目标方法
同名同参
Override
JVM决定目标方法
public class DynamicDispatch {
static abstract class Human{
protected abstract void sayHello();
}
static class Man extends Human{
@Override
protected void sayHello() {
System.out.println("man say hello");
}
}
static class Woman extends Human{
@Override
protected void sayHello() {
System.out.println("woman say hello");
}
}
public static void main(String[] args) {
Human man = new Man();
Human woman = new Woman();
man.sayHello();//man say hello
woman.sayHello();//woman say hello
}
}
