selectors.java

《j2ee开发全程实录》随书源码

package com.cownew.PIS.framework.common.db;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class Selectors implements Serializable
{
	private Set set;
	
	public Selectors()
	{
		set = new HashSet();
	}
	
	public Selectors(int capacity)
	{
		set = new HashSet(capacity);
	}

	public boolean add(String string)
	{
		return set.add(string);
	}

	public boolean remove(String string)
	{
		return set.remove(string);
	}
	
	public Iterator iterator()
	{
		return set.iterator();
	}

	public String toString()
	{
		return set.toString();
	}
	
	/**
	 * 产生以property为根的新的Selectors
	 * @param property
	 * @return
	 */
	public Selectors generateSubSelectors(String property)
	{
		property = property+".";
		Selectors newSelector = new Selectors();
		
		Iterator it = this.iterator();
		while(it.hasNext())
		{
			String item = it.next().toString();
			if(item.startsWith(property))
			{
				String subItem = item.substring(property.length());
				newSelector.add(subItem);
			}
		}
		return newSelector;
	}
	
	/**
	 * property属性是否被定义在Seletors中了
	 * @param property
	 * @return
	 */
	public boolean contains(String property)
	{
		Iterator it = this.iterator();
		while(it.hasNext())
		{
			String item = it.next().toString();
			if (item.startsWith(property))
			{
				return true;
			}
		}
		return false;
	}
	
	public static void main(String[] args)
	{
		Selectors s = new Selectors();
		s.add("department");
		s.add("manager.manager");
		s.add("manager.manager.manager");

		System.out.println(s.generateSubSelectors("manager"));
		System.out.println(s.contains("computer"));
		System.out.println(s.contains("manager.manager"));
	}
}