读取本地的xml文件，通过dom进行解析，dom解析的特点就是把整个xml文件装载入内存中，形成一颗dom树形结构，树结构是方便遍历和和操纵。
DOM解析的特性就是读取xml文件转换为 dom树形结构，通过节点进行遍历。
这是W3c关于节点的概念
如果xml中包含有大量的数据，由于dom一次性把xml装入内存中的特性，所以dom不适合于包含大量数据的xml解析。当包含有大量xml的时候，用SAX进行解析比较节省内存。
下面是一个运用DOM进行解析xml文件的例子：
立即学习“Java免费学习笔记（深入）”；
xml文件结构如下：
Everyday Italian Giada De Laurentiis 2005 30.00 Harry Potter J K. Rowling 2005 29.99 XQuery Kick Start James McGovern 2003 49.99 Learning XML Erik T. Ray 2003 39.95
创建解析xml的类如下：
package xml.dom;
import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class ReadXmlFile {
public static void main(String[] args) {
try{
File xmlFile = new File("src/resource/book.xml");
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document doc = builder.parse(xmlFile);
doc.getDocumentElement().normalize();
System.out.println("Root element: "+doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("book");
for(int i = 0 ; i解析结果：
Root element: bookstore
Node name: book
----------------------------
book category: cooking
title name: Everyday Italian
author name: Giada De Laurentiis
year :2005
price : 30.00
-------------------------
Node name: book
----------------------------
book category: children
title name: Harry Potter
author name: J K. Rowling
year :2005
price : 29.99
-------------------------
Node name: book
----------------------------
book category: web
title name: XQuery Kick Start
author name: James McGovern
year :2003
price : 49.99
-------------------------
Node name: book
----------------------------
book category: web
title name: Learning XML
author name: Erik T. Ray
year :2003
price : 39.95
-------------------------
以上是通过name获得对应的值，
下面利用循环节点的方式输出：
循环节点输出方式的代码如下：
package xml.dom;
import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class ReadXmlFile2 {
public static void main(String[] args) {
try{
File xmlFile = new File("src/resource/book.xml");
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document doc = builder.parse(xmlFile);
doc.getDocumentElement().normalize();
System.out.println("Root element: "+doc.getDocumentElement().getNodeName());
if(doc.hasChildNodes()){
printNode(doc.getChildNodes());
}
}catch(Exception e){
e.printStackTrace();
}
}
public static void printNode(NodeList nodeList){
System.out.println("------------------------");
// System.out.println(nodeList.getLength());
for(int i = 0; i输出结果如下：
Root element: bookstore
------------------------
node name: bookstore
node value:
Everyday Italian
Giada De Laurentiis
2005
30.00
Harry Potter
J K. Rowling
2005
29.99
XQuery Kick Start
James McGovern
2003
49.99
Learning XML
Erik T. Ray
2003
39.95
------------------------
node name: book
node value:
Everyday Italian
Giada De Laurentiis
2005
30.00
node name category
node value cooking
------------------------
node name: title
node value: Everyday Italian
node name lang
node value en
------------------------
node name: author
node value: Giada De Laurentiis
------------------------
node name: year
node value: 2005
------------------------
node name: price
node value: 30.00
------------------------
node name: book
node value:
Harry Potter
J K. Rowling
2005
29.99
node name category
node value children
------------------------
node name: title
node value: Harry Potter
node name lang
node value en
------------------------
node name: author
node value: J K. Rowling
------------------------
node name: year
node value: 2005
------------------------
node name: price
node value: 29.99
------------------------
node name: book
node value:
XQuery Kick Start
James McGovern
2003
49.99
node name category
node value web
------------------------
node name: title
node value: XQuery Kick Start
node name lang
node value en
------------------------
node name: author
node value: James McGovern
------------------------
node name: year
node value: 2003
------------------------
node name: price
node value: 49.99
------------------------
node name: book
node value:
Learning XML
Erik T. Ray
2003
39.95
node name category
node value web
node name cover
node value paperback
------------------------
node name: title
node value: Learning XML
node name lang
node value en
------------------------
node name: author
node value: Erik T. Ray
------------------------
node name: year
node value: 2003
------------------------
node name: price
node value: 39.95
------------------------
关于节点的问题：
Everyday Italian
Giada De Laurentiis
2005
30.00
对于 book应用：doc.getChildNodes() 得到一个NodeList其中NodeList的长度为9
9个节点分别如下：
title节点
lang节点
Everyday节点
author节点
Giada De Laurentiis节点
year节点
2005节点
price节点
30.00节点
更多java读取解析xml文件实例相关文章请关注PHP中文网！
