java学习笔记--解析xml

  java解析xml有多种方式，这里主要记录一下DOM解析和DOM4j解析
  首先我们准备一个简单的xml文件

<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
<book id="1">
<name>三体</name>
<author>刘慈欣</author>
<price>70</price>
</book>
<book id="2">
<name>红楼梦</name>
<author>曹雪芹</author>
<language>中文</language>
</book>
</bookstore>

DOM解析

DOM解析是java中自带的解析方式，主要实现代码如下

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.IOException;

/**
* Created by lenovo1 on 2017-03-10.
*/
public class DOMTest {
public static void main(String[] args) {
//创建一个DocumentBuilderFactory对象
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
//创建一个DocumentBuilder对象
try {
//创建DocumentBuilder对象
DocumentBuilder db = dbf.newDocumentBuilder();
//通过DocumentBuilder对象的parse方法加载books.xml文件到当前项目下
Document document = db.parse("books.xml");
//获取所有book结点的集合
NodeList bookList = document.getElementsByTagName("book");
//遍历每一个book节点
for (int i =0;i<bookList.getLength();i++) {
//通过item(i)方法 获取一个book节点，nodeList的索引值从0开始
Node book = bookList.item(i);
//获取book节点的所有属性集合
NamedNodeMap attrs = book.getAttributes();
//遍历book的属性
for (int j=0;j<attrs.getLength();j++) {
//通过item(index)方法获取book节点的某一个属性
Node attr = attrs.item(j);
//获取属性名
System.out.print("属性名：" + attr.getNodeName());
//获取属性值
System.out.println("--属性值" + attr.getNodeValue());
}
//解析book节点的子节点
NodeList childNodes = book.getChildNodes();
//遍历childNodes获取每个节点的节点名和节点值
for (int k = 0; k < childNodes.getLength(); k++) {
//区分出text类型的node以及element类型的node
if (childNodes.item(k).getNodeType() == Node.ELEMENT_NODE) {
//获取了element类型节点的节点名
System.out.print("节点名："+ childNodes.item(k).getNodeName());
System.out.println("--节点值是：" + childNodes.item(k).getTextContent());
}
}
}
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

DOM4j解析

  DOM4j解析不是java中自带的解析方式，需要外部导入jar包

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
* Created by lenovo1 on 2017-03-10.
*/
public class DOM4jTest {
private static ArrayList<Book> bookList = new ArrayList<Book>();
public static void main(String[] args) {
// 创建SAXReader的对象reader
SAXReader reader = new SAXReader();

try {
Document document = reader.read(new File("books.xml"));
Element bookStore = document.getRootElement();
Iterator it = bookStore.elementIterator();
while (it.hasNext()) {
System.out.println("=====开始遍历某一本书=====");
Element book = (Element) it.next();
// 获取book的属性名以及 属性值
List<Attribute> bookAttrs = book.attributes();
for (Attribute attr : bookAttrs) {
System.out.println("属性名：" + attr.getName() + "--属性值："
+ attr.getValue());
}
Iterator itt = book.elementIterator();
while (itt.hasNext()) {
Element bookChild = (Element) itt.next();
System.out.println("节点名：" + bookChild.getName() + "--节点值：" + bookChild.getStringValue());
}
System.out.println("=====结束遍历某一本书=====");
}

} catch (DocumentException e) {
e.printStackTrace();
}
}
}