package com.visit.theory;

import java.util.ArrayList;

public class Test

{

public static void main(String[] args)

{

ObjectStructure o = new ObjectStructure(); //依赖于ObjectStructure

//实例化具体元素

o.attach(new Man());

o.attach(new Woman());

//当成功时不同元素的不同反映

Visitor success = new Success(); //依赖于抽象的Visitor接口

o.display(success);

//当恋爱时的不同反映

Visitor amativeness = new Love(); //依赖于抽象的Visitor接口

o.display(amativeness);

}

}

package com.visit.theory;

public interface Visitor

{

public void visit(Man man);

public void visit(Woman w);

}

package com.visit.theory;

public interface Person

{

void accept(Visitor visitor);

}

package com.visit.theory;

public class Woman implements Person {

// 先对visitor进行类型转换，再执行visit方法，因为Visitor接口已经没有声明任何抽象方法了

public void accept(Visitor visitor) {

visitor.visit(this);

}

}

package com.visit.theory;

public class Man implements Person {

// 先对visitor进行类型转换，再执行visit方法，因为Visitor接口已经没有声明任何抽象方法了

public void accept(Visitor visitor) {

visitor.visit(this);

}

}

package com.visit.theory;

public class Success implements Visitor{

public void visit(Man man) {

System.out.println("当男人成功时，背后多半有一个伟大的女人");

}

public void visit(Woman girl) {

System.out.println("当女人成功时，背后大多有一个不成功的男人");

}

}

package com.visit.theory;

public class Love implements Visitor{

public void visit(Man man) {

System.out.println("当男人恋爱时，凡事不懂也装懂");

}

public void visit(Woman girl) {

System.out.println("当女人恋爱时，遇事懂也装不懂");

}

}

package com.visit.theory;

import java.util.ArrayList;

import java.util.List;

public class ObjectStructure

{

private List elements = new ArrayList();

public void attach(Person element){

elements.add(element);

}

public void detach(Person element){

elements.remove(elements);

}

//遍历各种具体元素并执行他们的accept方法

public void display(Visitor visitor){

for(Person p:elements){

p.accept(visitor);

}

}

}