dom4j组装xml 以及解析xml：
1.下载dom4j的jar包，地址：https://dom4j.github.io/
2.java代码：
package test; import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map; import javax.xml.parsers.ParserConfigurationException; import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.xml.sax.SAXException; /**
* dom4j解析xml
* @author lyc
*
*/
public class DOM4J { public static void main(String[] args) {
DOM4J dom4j= new DOM4J();
try {
//生成xml
dom4j.objectToXml();
//解析xml
//dom4j.xmlToObject();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} // 获取并解析xml格式文件为object
public void xmlToObject() throws ParserConfigurationException, DocumentException, SAXException, IOException{
/**
* 1.解析xml文件
*/
SAXReader saxReader = new SAXReader();
//将获取的xml 转化为document 文档
//这里使用了File当然也可以使用URL()从指定url获取xml并进行解析
//document从文件中解析出来
//Document document = saxReader.read(new File("src/1.xml")); /**
* 2.解析xml字符串
*/
//解析xml字符串
//document从字符串中解析出来
String xml = "<?xml version='1.0' encoding='UTF-8'?><student name='zhangsan'><courses><yuwen>语文</yuwen><shuxue>数学</shuxue></courses><courses><yingyu>英语</yingyu><huaxue>化学</huaxue></courses></student>";
Document document = DocumentHelper.parseText(xml); // 将字符串转为XML
// 获取根元素
Element root = document.getRootElement();
// 根元素名称
System.out.println("reservationList Root----: " + root.getName()); // 获取所有子元素
List<Element> childList = root.elements(); //解析xml串
System.out.println(childList.get(0).element("yuwen").getTextTrim());
System.out.println("courses child 长度：" + childList.size());
for(Element e : childList){
List<Element> list = e.elements();
for(Element e1 : list){
System.out.println(e1.getTextTrim());
}
System.out.println("==========");
} System.out.println("total reservation child count: " + childList.size());
System.out.println("第一个reservation的quotationId节点值："+childList.get(0).element("quotationId").getTextTrim());
for(Element e : childList){
/*Element helloElement = e.element("quotationId");
System.out.println(helloElement.getTextTrim());*/ Element insurantListE = e.element("insurantList");
List<Element> insurantList = insurantListE.elements();
System.out.println("total insurant child count: " + insurantList.size());
for(Element e1 : insurantList){
Element helloElement1 = e1.element("insurantName");
System.out.println(helloElement1.getTextTrim());
}
} /*// 获取特定名称的子元素
List<Element> childList2 = root.elements("reservation");
Element helloElement = root.element("quotationId");
System.out.println("hello child: " + childList2.size());
// 获取特定名称的子元素的值
System.out.println("hello----"+childList2.get(0).getText());
System.out.println("hello----"+helloElement.getText().trim());
System.out.println("迭代输出-----------------------");*/ // 迭代输出
/*for (Iterator iter = root.elementIterator(); iter.hasNext();)
{ // 获取根目录下的元素
Element e = (Element) iter.next();
// 获取元素对应的值
System.out.println(e.getText());
// 元素的属性个数
System.out.println(e.attributeCount());
//获取元素的第一个属性的名称
System.out.println(e.attribute(0).getName());
//获取元素的第一个属性的值
System.out.println(e.attribute(0).getValue());
//获取元素的第二个属性的名称
System.out.println(e.attribute(1).getName());
//获取元素的第二个属性的值
System.out.println(e.attribute(1).getValue());
//按照属性名称获取属性值
System.out.println("are you ok :"+e.attributeValue("age"));
System.out.println("are you ok :"+e.attributeValue("name"));
}*/ // 使用DOMReader将xml转化为object
/*System.out.println("用DOMReader-----------------------");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
// 注意要用完整类名
//将获取的xml 转化为document 文档
org.w3c.dom.Document document2 = db.parse(new File("F:/student2.xml")); DOMReader domReader = new DOMReader(); // 将JAXP的Document转换为dom4j的Document
Document document3 = domReader.read(document2); Element rootElement = document3.getRootElement(); System.out.println("Root: " + rootElement.getName());*/
} // 将对象组装成xml格式文件并保存
public void objectToXml ()throws Exception{
// 第一种方式：创建文档，并创建根元素
// 创建文档:使用了一个Helper类
Document document = DocumentHelper.createDocument();
// 创建根节点并添加进文档
Element root = DocumentHelper.createElement("student");
document.setRootElement(root); // 第二种方式:创建文档并设置文档的根元素节点
Element root2 = DocumentHelper.createElement("student");
Document document2 = DocumentHelper.createDocument(root2);
// 给元素添加属性
root2.addAttribute("name", "zhangsan"); Element e = root2.addElement("courses");
/*Map<String,Object> map1 = new HashMap<String,Object>();
Map<String,Object> map2 = new HashMap<String,Object>();
List<Map<String,Object>> list = new ArrayList(); map2.put("yuwen", "语文");
map2.put("shuxue", "数学");
list.add(map1);
list.add(map2);*/ /*for(Map map : list){
Element courseElement = e.addElement(map.entrySet().iterator().next().toString());
courseElement.setText(map.get(map.entrySet().iterator().next().toString()).toString());
}*/ Element yuwenElement = e.addElement("yuwen");
Element shuxueElement = e.addElement("shuxue"); yuwenElement.setText("语文");
shuxueElement.setText("数学"); /**
* 1.生成xml字符串
*/
//生成xml字符串方式一：
String xmlText = document2.asXML();
System.out.println(xmlText); //生成xml字符串方式二：
/*OutputFormat format1 = OutputFormat.createCompactFormat(); //createPrettyPrint() 层次格式化
StringWriter writer = new StringWriter();
XMLWriter output = new XMLWriter(writer, format1);
output.write(document);
System.out.println();
System.out.println("xmlToString:"+writer.toString());*/ /**
* 2.生成xml文件
*/
/* // 添加子节点:add之后就返回这个元素
Element helloElement = root2.addElement("hello");
Element worldElement = root2.addElement("world");
//给元素添加属性key-value
worldElement.addAttribute("age","12");
worldElement.addAttribute("name","www");
helloElement.addAttribute("age","13");
helloElement.addAttribute("name","wws");
//元素的节点的值
helloElement.setText("hello Text");
worldElement.setText("world text");*/
// 输出
// 输出到控制台
XMLWriter xmlWriter = new XMLWriter();
xmlWriter.write(document); //输出到文件
//其中的" "表示格式，true参数表示另起一行，gb2312表示编码,如果不写这个参数则默认utf-8编码
//1、OutputFormat format=new OutputFormat(" ",true,"gb2312");
//生成压缩格式、紧凑格式的xml 其中的compactFormat 翻译：压缩格式
//2、 OutputFormat format = OutputFormat.createCompactFormat();
//调用静态方法创建一个没有格式的打印方式
//3、 OutputFormat format = OutputFormat.createPrettyPrint();
//format.setEncoding("gb2312"); // 设置编码
OutputFormat format = new OutputFormat(" ", true);// 设置缩进为2个空格，并且另起一行为true
XMLWriter xmlWriter2 = new XMLWriter(
new FileOutputStream("C:/Users/lyc/Desktop/student1.xml"), format);
xmlWriter2.write(document2);
xmlWriter2.flush();
xmlWriter2.close(); // 另一种输出方式，记得要调用flush()方法,否则输出的文件中显示空白，调用close() 方法释放资源
XMLWriter xmlWriter3 = new XMLWriter(new FileWriter("C:/Users/lyc/Desktop/student2.xml"),
format);
xmlWriter3.write(document2);
xmlWriter3.flush();
xmlWriter3.close();
} }
3.需要解析的xml内容：
1.xml：（自己定义xml文件），例如：
<?xml version="1.0" encoding="UTF-8"?> <student name="zhangsan">
<courses>
<yuwen>语文</yuwen>
<shuxue>数学</shuxue>
</courses>
</student>
4.生成xml文件：
student1.xml：
<?xml version="1.0" encoding="UTF-8"?> <student name="zhangsan">
<courses>
<yuwen>语文</yuwen>
<shuxue>数学</shuxue>
</courses>
</student>
student2.xml：
<?xml version="1.0" encoding="UTF-8"?> <student name="zhangsan">
<courses>
<yuwen>语文</yuwen>
<shuxue>数学</shuxue>
</courses>
</student>