XML 使用Stax 基于XPath 和XMLEventReader迭代模型 和过滤方式的解析
<bookstore>
?
<book category="COOKING">
? <title lang="en">Everyday Italian</title>
? <author>Giada De Laurentiis</author>
? <year>2005</year>
? <price>30.00</price>
</book>
<book category="CHILDREN">
? <title lang="en">Harry Potter</title>
? <author>J K. Rowling</author>
? <year>2005</year>
? <price>29.99</price>
</book>
?
<book category="WEB">
? <title lang="en">Learning XML</title>
? <author>Erik T. Ray</author>
? <year>2003</year>
? <price>39.95</price>
</book>
</bookstore>
?
?package xml.sg.stax;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.stream.EventFilter;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.events.XMLEvent;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class TestStax {
?// Stax解析xml
?@Test
?public void test01() {
??XMLInputFactory factory = XMLInputFactory.newInstance();
??InputStream stream = null;
??try {
???stream = TestStax.class.getClassLoader().getResourceAsStream(
?????"book.xml");
???XMLStreamReader reader = factory.createXMLStreamReader(stream);
???while (reader.hasNext()) {
????int len = reader.next();
????// 判断是否是开始元素
????if (len == XMLStreamConstants.START_ELEMENT) {
?????String name = reader.getName().toString();
?????if (name.equals("book")) {
??????System.out.println(reader.getAttributeName(0) + ":"
????????+ reader.getAttributeValue(0));
?????}
????}
???}
??} catch (XMLStreamException e) {
???e.printStackTrace();
??} finally {
???if (stream != null) {
????try {
?????stream.close();
????} catch (IOException e) {
?????e.printStackTrace();
????}
???}
??}
?}
?@Test
?public void test02() {
??XMLInputFactory factory = XMLInputFactory.newInstance();
??InputStream stream = null;
??try {
???stream = TestStax.class.getClassLoader().getResourceAsStream(
?????"book.xml");
???XMLStreamReader reader = factory.createXMLStreamReader(stream);
???while (reader.hasNext()) {
????int len = reader.next();
????// 判断是否是开始元素
????if (len == XMLStreamConstants.START_ELEMENT) {
?????String name = reader.getName().toString();
?????if (name.equals("title")) {
??????System.out.println(reader.getElementText() + ":");
?????}
?????if (name.equals("price")) {
??????System.out.println(reader.getElementText() + "/n");
?????}
????}
???}
??} catch (XMLStreamException e) {
???e.printStackTrace();
??} finally {
???if (stream != null) {
????try {
?????stream.close();
????} catch (IOException e) {
?????e.printStackTrace();
????}
???}
??}
?}
?@Test
?public void test03() {
??XMLInputFactory factory = XMLInputFactory.newInstance();
??InputStream stream = null;
??try {
???stream = TestStax.class.getClassLoader().getResourceAsStream(
?????"book.xml");
???// 基于迭代模型操作
???XMLEventReader reader = factory.createXMLEventReader(stream);
???while (reader.hasNext()) {
????// 通过XMLEvent来获取是否是某种节点类型
????XMLEvent event = reader.nextEvent();
????// 判断是否是开始元素
????if (event.isStartElement()) {
?????// 通过event.asxxx来转换节点
?????String name = event.asStartElement().getName().toString();
?????if (name.equals("title")) {
??????System.out.println(reader.getElementText() + ":");
?????}
?????if (name.equals("price")) {
??????System.out.println(reader.getElementText() + "/n");
?????}
????}
???}
??} catch (XMLStreamException e) {
???e.printStackTrace();
??} finally {
???if (stream != null) {
????try {
?????stream.close();
????} catch (IOException e) {
?????e.printStackTrace();
????}
???}
??}
?}
?@Test
?public void test04() {
??XMLInputFactory factory = XMLInputFactory.newInstance();
??InputStream stream = null;
??try {
???stream = TestStax.class.getClassLoader().getResourceAsStream(
?????"book.xml");
???// 基于Filter的过滤方式 可以有效过滤掉不用进行操作的节点 效率更高一些
???XMLEventReader reader = factory.createFilteredReader(
?????factory.createXMLEventReader(stream), new EventFilter() {
??????@Override
??????public boolean accept(XMLEvent event) {
???????if (event.isStartElement()) {
????????return true;
???????}
???????return false;
??????}
?????});
???while (reader.hasNext()) {
????// 通过XMLEvent来获取是否是某种节点类型
????XMLEvent event = reader.nextEvent();
????// 判断是否是开始元素
????if (event.isStartElement()) {
?????// 通过event.asxxx来转换节点
?????String name = event.asStartElement().getName().toString();
?????if (name.equals("title")) {
??????System.out.println(reader.getElementText() + ":");
?????}
?????if (name.equals("price")) {
??????System.out.println(reader.getElementText() + "\n");
?????}
????}
???}
??} catch (XMLStreamException e) {
???e.printStackTrace();
??} finally {
???if (stream != null) {
????try {
?????stream.close();
????} catch (IOException e) {
?????e.printStackTrace();
????}
???}
??}
?}
?@Test
?public void test05() {
??InputStream stream = null;
??try {
???stream = TestStax.class.getClassLoader().getResourceAsStream(
?????"book.xml");
???//创建文档处理对象
???DocumentBuilder builder = DocumentBuilderFactory.newInstance()
?????.newDocumentBuilder();
???//通过DocumentBuilder创建文档对象
???Document document = builder.parse(stream);
???//创建XPath
???XPath xPath = XPathFactory.newInstance().newXPath();
???//第一个参数是xpath 第二个参数是文档 找category='WEB'的title
???NodeList nodeList = (NodeList) xPath.evaluate("//book[@category='WEB']", document,XPathConstants.NODESET);
???for (int i = 0; i < nodeList.getLength(); i++) {
????//遍历输入的相应结果
????Element element = (Element) nodeList.item(i);
????System.out.println(element.getElementsByTagName("title").item(0).getTextContent());
???}
???
??} catch (XPathExpressionException e) {
???e.printStackTrace();
??} catch (SAXException e) {
???e.printStackTrace();
??} catch (IOException e) {
???e.printStackTrace();
??} catch (ParserConfigurationException e) {
???e.printStackTrace();
??}
?}
}
?
?
?
