访问者模式---打包员

今天做了访问者模式---打包员的实验，用了差不多两个小时的时间，理解了访问者模式的原理，下面是访问者模式的实验要求和实现。

实验要求：

在我们课堂上的“购物车”的例子中，增加一个新的访问者：打包员，负责对购物车中货物装包。

截图：

 

 代码：

public class Apple implements Product {
public Apple() {
} public void accept(Visitor visitor) {
visitor.visit(this);
}
}
public class Book implements Product {
public Book() {
} public void accept(Visitor visitor) {
visitor.visit(this);
}
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//import java.util.ArrayList;
import java.util.Iterator;public class BuyBasket {
private ArrayList list = new ArrayList(); public BuyBasket() {
} public void accept(Visitor visitor) {
Iterator i = this.list.iterator(); while(i.hasNext()) {
((Product)i.next()).accept(visitor);
} }
public void addProduct(Product product) {
this.list.add(product);
} public void removeProduct(Product product) {
this.list.remove(product);
}
}

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//public class Client {
public Client() {
} public static void main(String[] a) {
Product b1 = new Book();
Product b2 = new Book();
Product a1 = new Apple(); Packer packer = new Packer();
BuyBasket basket = new BuyBasket();
basket.addProduct(b1);
basket.addProduct(b2);
basket.addProduct(a1); Visitor visitor = (Visitor)XMLUtil.getBean();
visitor.setName("张三");
basket.accept(visitor);
}
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//public class Customer extends Visitor {
public Customer() {
} public void visit(Apple apple) {
System.out.println("顾客" + this.name + "选苹果。");
} public void visit(Book book) {
System.out.println("顾客" + this.name + "买书。");
}
}
public class Packer extends Visitor {
@Override
public void visit(Apple var1) {
System.out.println("打包员"+name+"打包苹果！");
} @Override
public void visit(Book var1) {
System.out.println("打包员"+name+"包装书籍！"); }
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//public interface Product {
void accept(Visitor var1);
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//public class Saler extends Visitor {
public Saler() {
} public void visit(Apple apple) {
System.out.println("收银员" + this.name + "给苹果过秤，然后计算其价格。");
} public void visit(Book book) {
System.out.println("收银员" + this.name + "直接计算书的价格。");
}
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//public abstract class Visitor {
protected String name; public Visitor() {
} public void setName(String name) {
this.name = name;
} public abstract void visit(Apple var1);
public abstract void visit(Book var1);
}
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;public class XMLUtil {
public XMLUtil() {
} public static Object getBean() {
try {
DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = dFactory.newDocumentBuilder();
Document doc = builder.parse(new File("config.xml"));
NodeList nl = doc.getElementsByTagName("className");
Node classNode = nl.item(0).getFirstChild();
String cName = classNode.getNodeValue();
Class c = Class.forName(cName);
Object obj = c.newInstance();
return obj;
} catch (Exception var8) {
var8.printStackTrace();
return null;
}
}
}