Java操作XML文件(2)-读取XML文件

使用Java读取XML文件：

package xml;

import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class XMLReader {
	private String fileName;

	public XMLReader(String fileName) {
		this.fileName = fileName;
	}

	public Element getRootElement() throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse(fileName);
		return document.getDocumentElement();
	}

	public List<Element> getElementsByTagName(Element parent, String tagName) {
		List<Element> elements = new ArrayList<Element>();
		if (parent != null) {
			NodeList list = parent.getElementsByTagName(tagName);
			for (int i = 0; i < list.getLength(); i++) {
				elements.add((Element) list.item(i));
			}
		}
		return elements;
	}

	public Element getElementByTagName(Element parent, String tagName, int index) {
		List<Element> elements = getElementsByTagName(parent, tagName);
		if (index < 0 || index >= elements.size()) {
			return elements.get(0);
		} else {
			return elements.get(index);
		}
	}

	public String getTextContent(Element e) {
		return e.getTextContent();
	}

	public String getAttribute(Element e, String name) {
		return e.getAttribute(name);
	}

	public static void main(String[] args) {
		try {
			XMLReader reader = new XMLReader("E:\\test.xml");
			Element root = reader.getRootElement();
			System.out
					.println(reader.getElementsByTagName(root, "Book").size());
			Element book = reader.getElementByTagName(root, "Book", 0);
			Element price = reader.getElementByTagName(book, "Price", 0);
			System.out.println(price.getTextContent());
			Element title = reader.getElementByTagName(book, "Title", 0);
			System.out.println(reader.getTextContent(title));
			System.out.println(reader.getAttribute(title, "Auth"));
		} catch (Exception e) {
			e.printStackTrace();
		}

	}
}