Android XML解析技术——DOM

最新推荐文章于 2021-05-27 09:59:29 发布

原创最新推荐文章于 2021-05-27 09:59:29 发布 · 558 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一个使用Java DOM解析XML文件的示例程序。该程序定义了Book类来存储书籍信息，并通过DomService类中的getBooks方法读取XML文件中的书籍数据。此外，还对比了DOM与其他XML解析方式的效率。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1、Book类

public class Book {
	
	private int id;
	private String name;
	private float price;

	public Book() {
		// TODO 自动生成的构造函数存根
	}

	public Book(int id, String name, float price) {
		super();
		this.id = id;
		this.name = name;
		this.price = price;
	}
	
	
	

	public int getId() {
		return id;
	}


	public void setId(int id) {
		this.id = id;
	}


	public String getName() {
		return name;
	}


	public void setName(String name) {
		this.name = name;
	}


	public float getPrice() {
		return price;
	}


	public void setPrice(float price) {
		this.price = price;
	}

	@Override
	public String toString() {
		return "Book [id=" + id + ", name=" + name + ", price=" + price
				+ "]";
	}
	
}

2、HttpUtil类

public class httpUtils {
	public httpUtils() {
		// TODO 自动生成的构造函数存根
	}
	
	public static InputStream getXML(String path){
		InputStream inputStream = null;
		try {
			URL url = new URL(path);
			if(url != null){
				HttpURLConnection connection = (HttpURLConnection) url.openConnection();
				connection.setConnectTimeout(3000);
				connection.setDoInput(true);
				connection.setRequestMethod("GET");
				int code = connection.getResponseCode();
				if(code == 200){
					inputStream = connection.getInputStream();
				}
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return inputStream;
	}		
}

3、解析实体类

public class DomService {

	public DomService() {
		// TODO 自动生成的构造函数存根
	}
	
	public List<Book> getBooks(InputStream inputStream) throws ParserConfigurationException, SAXException, IOException{
		List<Book> list 	= new ArrayList<Book>();
		//创建一个document解析的工厂
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse(inputStream);
		Element element = document.getDocumentElement();//得到稳定的元素节点
		NodeList bookNodes = element.getElementsByTagName("book");
		for(int i = 0; i<bookNodes.getLength(); i++){
			Element bookElement = (Element) bookNodes.item(i);
			Book book = new Book();
			book.setId(Integer.parseInt(bookElement.getAttribute("id")));
			NodeList childNodes = bookElement.getChildNodes();// 遍历根节点下的子节点
			for(int j = 0;  j<childNodes.getLength();j++){
				if(childNodes.item(j).getNodeType() == Node.ELEMENT_NODE){
					if("name".equals(childNodes.item(j).getNodeName())){
						book.setName(childNodes.item(j).getFirstChild().getNodeValue());
					} else if("price".equals(childNodes.item(j).getNodeName())){
						book.setPrice(Float.parseFloat(childNodes.item(j).getFirstChild().getNodeValue()));
					}
				}
			}
			list.add(book);
		}
		
		return list;
	}
	
	public static void main(String args[]) throws ParserConfigurationException, SAXException, IOException{
		String path = "http://192.168.0.102:8080/MyHttp/book.xml";
		InputStream inputStream = httpUtils.getXML(path);
		
		DomService service = new DomService();
		List<Book> list = service.getBooks(inputStream);
		for(Book book:list){
			System.out.println(book.toString());
		}
	}
}
/*输出结果：
 * [id = 12, name = thinking in java, price = 85.5]
 * [id = 15, name = Spring in Action, price = 39.0]
 * 
 * DOM解析XML文件相比其他两种解析方式，效率低下，
 * 如果当前如果有很多个子节点，再取一次字节点，所以效率比较低，所以一般使用的时候比较少
 * */

/*=========SAX、DOM和PULL的比较
 * 从内存占用率来说：SAX和PULL比DOM占用更少的内存解析方式，更加适合Android 开发
 * 
 * 
 * */