访问者模式的一个小例子

Posted 2021-06-17 你可以当我没名字

用junit来测试代码

public class fwzTest {
    @Test
    public void Test1(){
        VistorBei girl = new Girl();
        VistorBei guy = new Guy();
        China china = new China();
        china.add(girl);
        china.add(guy);
        Vistor enemy = new Enemy();
        Vistor friend = new Friend();
        china.accept(enemy);
        china.accept(friend);
    }
}

public class China {
    private List<VistorBei> vb = new ArrayList<>();
    public void add(VistorBei vistorBei){
        vb.add(vistorBei);
    }
    public void accept(Vistor vistor){
        for (Object o : vb) {
            ((VistorBei) o).accept(vistor);
        }
    }
}

public interface Vistor {
    void visitGril(Girl girl);
    void visitGuy(Guy guy);
}

public interface VistorBei {
    void accept(Vistor v);
}

public class Friend implements Vistor{

    @Override
    public void visitGril(Girl girl) {
        girl.dance();
    }

    @Override
    public void visitGuy(Guy guy) {
        guy.handshake();
    }
}

public class Enemy implements Vistor{
    @Override
    public void visitGril(Girl girl) {
        girl.kill();
    }

    @Override
    public void visitGuy(Guy guy) {
        guy.kill();
    }
}

public class Girl implements VistorBei{

    @Override
    public void accept(Vistor v) {
        v.visitGril(this);
    }

    public void dance(){
        System.out.println("跳舞~");
    }

    public void kill(){
        System.out.println("砍你~");
    }
}

public class Guy implements VistorBei{
    @Override
    public void accept(Vistor v) {
        v.visitGuy(this);
    }

    public void handshake(){
        System.out.println("握手~");
    }

    public void kill(){
        System.out.println("拿烟头烫你~");
    }
}