1、流行的XML解析框架
1》底层解析方式：存在编码复杂性、难扩展、难复用….。想了解底层解析方式请参考：浅谈 Java XML 底层解析方式
2》Dom4j：基于 JAXP 解析方式，性能优异、功能强大、极易使用的优秀框架。
3》Jdom：本质也是基于 JAXP 但包结构被重新组织， API 大量使用了 Collections 类，在性能上被 dm4j 压了好几个档次。
4》XStream：基于 xmlpull 的 OXMapping 技术，更加倾向于将 XML 解析后映射为 Java 世界中的对象。
2、建立一个简单的demo.xml文件，用于提供给各种方式解析
<?xml version="1.0"?>
<classGrid>
<classGridlb>
<class_id>320170105000009363</class_id>
<class_number>0301</class_number>
<adviser>018574</adviser>
<studentGrid>
<studentGridlb>
<stu_id>030101</stu_id>
<stu_name>齐天</stu_name>
<stu_age>9</stu_age>
<stu_birthday>2008-11-07</stu_birthday>
</studentGridlb>
<studentGridlb>
<stu_id>030102</stu_id>
<stu_name>张惠</stu_name>
<stu_age>10</stu_age>
<stu_birthday>2009-04-08</stu_birthday>
</studentGridlb>
<studentGridlb>
<stu_id>030103</stu_id>
<stu_name>龙五</stu_name>
<stu_age>9</stu_age>
<stu_birthday>2008-11-01</stu_birthday>
</studentGridlb>
</studentGrid>
</classGridlb>
<classGridlb>
<class_id>420170105000007363</class_id>
<class_number>0302</class_number>
<adviser>018577</adviser>
<studentGrid>
<studentGridlb>
<stu_id>030201</stu_id>
<stu_name>马宝</stu_name>
<stu_age>10</stu_age>
<stu_birthday>2009-09-02</stu_birthday>
</studentGridlb>
</studentGrid>
</classGridlb>
</classGrid>
3、Dom4j、Jdom、Xstream不同的解析方式
1》Dom4j方式，性能好，API灵活，支持对 XML 文档的增删改查动作，毕竟是以树模型加载到内存中进行的操作。有可能成为将来的主流。项目结构如下：
pom.xml
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6.1</version>
<exclusions>
<exclusion>
<groupId>xml-apis</groupId>
<artifactId>xml-apis</artifactId>
</exclusion>
</exclusions>
</dependency>
剔除 xml-apis 的用意 JDK 中已经有对应的类。
App.java
package com.lfy.cn.javaXmlPasareTest;import java.io.File;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;/**
*
*
*/
public class App
{
public static void main( String[] args ) throws DocumentException, ParseException{
String path = System.getProperty("user.dir")+"\\src\\demo.xml";
SAXReader reader = new SAXReader();
Document document = reader.read(new File(path)); List<StudentGridlb> studentGridlbList = new ArrayList<>();
StudentGridlb studentGridlbVo;
for (Object classGridlb : document.getRootElement().elements("classGridlb")) {
Element classGridlbEle = (Element) classGridlb;
DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
for (Object studentGridlb : classGridlbEle.element("studentGrid").elements("studentGridlb")) {
Element studentGridlbEle = (Element) studentGridlb; studentGridlbVo = new StudentGridlb();
studentGridlbVo.setStu_id(studentGridlbEle.elementTextTrim("stu_id"));
studentGridlbVo.setStu_age(Integer.parseInt(studentGridlbEle.elementTextTrim("stu_age")));
studentGridlbVo.setStu_name(studentGridlbEle.elementTextTrim("stu_name"));
studentGridlbVo.setStu_birthday(format.parse(studentGridlbEle.elementTextTrim("stu_birthday")));
studentGridlbList.add(studentGridlbVo);
}
}
System.out.println(studentGridlbList);
}
}
运行结果：
2》Jdom，基于树处理 XML，需要将树加载到内存中，所以解析大文件对内存的要求比较高。支持对 XML 文档的增删改查动作，毕竟是以树模型加载到内存中进行的操作。解析速度还可以。
pom.xml
<dependency>
<groupId>jdom</groupId>
<artifactId>jdom</artifactId>
<version>1.1</version>
</dependency>
JdomTest.java
package com.lfy.cn.javaXmlPasareTest;import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.XMLOutputter;/**
*
*
*/
public class JdomTest
{
public static void main( String[] args ) throws ParseException, FileNotFoundException, IOException, JDOMException{ String path = System.getProperty("user.dir")+"\\src\\demo.xml"; SAXBuilder jdomsaxBuilder = new SAXBuilder(false);
Document doc = jdomsaxBuilder.build(path);
Element rootElement = doc.getRootElement(); List<StudentGridlb> studentGridlbList = new ArrayList<>();
StudentGridlb studentGridlb;
for (Object classGridlb : rootElement.getChildren("classGridlb")) {
Element classGridlbEle = (Element) classGridlb;
DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
for (Object studentGrid : classGridlbEle.getChild("studentGrid").getChildren("studentGridlb")) {
Element studentGridEle = (Element) studentGrid;
studentGridlb = new StudentGridlb();
studentGridlb.setStu_id(studentGridEle.getChildTextTrim("stu_id"));
studentGridlb.setStu_age(Integer.parseInt(studentGridEle.getChildTextTrim("stu_age")));
studentGridlb.setStu_name(studentGridEle.getChildTextTrim("stu_name"));
studentGridlb.setStu_birthday(format.parse(studentGridEle.getChildTextTrim("stu_birthday")));
studentGridlbList.add(studentGridlb);
}
}
XMLOutputter outputter = new XMLOutputter();
outputter.output(doc, new FileOutputStream(path));
System.out.println(studentGridlbList);
}
}
3》Xstream：基于注解不需要其它辅助类或映射文件 的OXMapping 技术。可以将 JavaBean 序列化为 XML，或将 XML 反序列化为 JavaBean，使得XML序列化不再繁琐。也可以将 JavaBean 序列化成 Json 或反序列化，使用非常方便。没有映射文件而且底层使用 xmlpull 推模型解析 XML，高性能、低内存占用，结合简洁明了的 API，上手基本是分分钟的事情。
