classservice.java

Ajax开发精要——概念、案例与框架.很适合初学者学习。

package com.ajaxlab.ajax;

import org.jdom.*;
import org.jdom.input.*;
import java.util.*;

public class ClassService {
	private Document dom;
	/**
	 * 构造函数，初始化XML文档根结点
	 *
	 */
	public ClassService() {
		try {
			SAXBuilder builder = new SAXBuilder();
			//this.dom = builder.build(new File("/ajaxlab/src/com/ajaxlab/ajax/products.xml"));
			//this.dom = builder.build(ClassService.class.getClassLoader().getResourceAsStream("products.xml"));
			this.dom = builder.build(ClassService.class.getResource("products.xml"));
		}catch(Exception ex) {
			System.out.println(ex.toString());
		}
	}
	/**
	 * 取得XML文档第一级结点
	 * @return
	 */
	public ProductClass[] getAllClass1() {
		Collection products = new ArrayList();
		Iterator iterator = this.dom.getRootElement().getChildren().iterator();
		do {
			Element element = (Element)iterator.next();
			ProductClass product = new ProductClass(element.getAttributeValue("id"),element.getAttributeValue("className"));
			products.add(product);
		}while(iterator.hasNext());
		return (ProductClass[])products.toArray(new ProductClass[0]);
	}
	/**
	 * 取得XML文档指定的第二级结点
	 * @param class1Id
	 * @return
	 */
	public ProductClass[] getClass2ById(String class1Id) {
		Collection products = new ArrayList();
		Element class1Element = null;
		Iterator iterator = this.dom.getRootElement().getChildren().iterator();
		do {
			Element element = (Element)iterator.next();
			if(class1Id.equalsIgnoreCase(element.getAttributeValue("id"))) {
				class1Element = element;
				break;
			}
		}while(iterator.hasNext());
		
		if(class1Element!=null) {
			Iterator iter = class1Element.getChildren().iterator();
			do {
				Element element = (Element)iter.next();
				ProductClass product = new ProductClass(element.getAttributeValue("id"),element.getAttributeValue("className"));
				products.add(product);
			}while(iter.hasNext());
			return (ProductClass[])products.toArray(new ProductClass[0]);
		}
		else return null;
	}
	/**
	 * 取得XML文档指定的第三级结点
	 * @param class1Id
	 * @param class2Id
	 * @return
	 */
	public ProductClass[] getClass3ById(String class1Id,String class2Id) {
		Collection products = new ArrayList();
		Element class1Element = null;
		Element class2Element = null;
		
		Iterator iterator = this.dom.getRootElement().getChildren().iterator();
		do {
			Element element = (Element)iterator.next();
			if(class1Id.equalsIgnoreCase(element.getAttributeValue("id"))) {
				class1Element = element;
				break;
			}
		}while(iterator.hasNext());
		
		if(class1Element!=null) {
			Iterator iter = class1Element.getChildren().iterator();
			do {
				Element element = (Element)iter.next();
				if(class2Id.equalsIgnoreCase(element.getAttributeValue("id"))) {
					class2Element = element;
					break;
				}
			}while(iter.hasNext());
			
			if(class2Element!=null) {
				Iterator iter2 = class2Element.getChildren().iterator();
				do {
					Element element = (Element)iter2.next();
					ProductClass product = new ProductClass(element.getAttributeValue("id"),element.getAttributeValue("className"));
					products.add(product);
				}while(iter2.hasNext());
			}
			return (ProductClass[])products.toArray(new ProductClass[0]);
		}
		else return null;
	}
	
	public static void main(String[] args) {
		try {
			ClassService service = new ClassService();
			System.out.println(service.getAllClass1().length);
			System.out.println(service.getClass2ById("1").length);
			System.out.println(service.getClass3ById("1","1").length);
		}catch(Exception ex) {
			ex.printStackTrace();
		}
	}
}