registerhashset.java

高质量Java程序设计 源代码

package net.betterjava.design.collection.shadowcopy;
import java.util.HashSet;
import java.util.Iterator;

public class RegisterHashSet implements Cloneable {
	private HashSet visitors;

	public RegisterHashSet() {
		visitors = new HashSet();
	}

	public RegisterHashSet(HashSet para) {
		visitors = para;
	}

	public void add(Visitor v) {
		visitors.add(v);
	}

	public Object clone() {
		return new RegisterHashSet((HashSet) visitors.clone());
	}

	public void amendFirstAddress(String newAddress) {
		Iterator it = visitors.iterator();
		if (it.hasNext()) {
			Visitor v = (Visitor) it.next();
			v.setAddress(newAddress);
		}
	}

	public String toString() {
		StringBuffer temp = new StringBuffer();
		Iterator it = visitors.iterator();
		while (it.hasNext()) {
			Visitor v = (Visitor) it.next();
			temp.append(v.getName()).append(":").append(v.getAddress()).append("\n");
		}
		return temp.toString();
	}

	public static void main(String[] args) {
		RegisterHashSet r = new RegisterHashSet();
		r.add(new Visitor("Alex", "Fa Hua Zhen Road"));
		r.add(new Visitor("Field", "Xiao Mu Qiao Road"));
		System.out.println(r);

		RegisterHashSet copy = (RegisterHashSet) r.clone();
		copy.amendFirstAddress("Fan Yu Road");
		System.out.println(r);
	}
}