1.准备工具：
dom4j依赖：
<dependency>
  <groupId>dom4j</groupId>
  <artifactId>dom4j</artifactId>
  <version>1.6.1</version>
</dependency>
junit测试工具依赖：
<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <version>4.11</version>
</dependency>
自定义xml文件student.xml：
<?xml version="1.0" encoding="utf-8"?>
<students>
  <student banji="1班">
  <name>小红书</name>
  <number>1411124</number>
  <age>12</age>
</student>
<student banji="2班">
  <name>小明</name>
  <number>1411125</number>
  <age>16</age>
</student>
</books>

2.解析xml
public class Dom4jTest {
@Test
  public void test1(){
  //获取SAXReader输入流
    SAXReader saxReader = new SAXReader();
    try {
    /**
    *1.读取book.xml文件并返回Document对象，
    */
    Document document = saxReader.read("student.xml");
    //2.读取文件的根元素
    Element root = document.getRootElement();
    List<Element> students = root.elements();
// asXML() 把标签对象,转化为标签字符串
    for(Element student : students){
      System.out.println(student.asXML());
      Element nameElement = student.element("name");
      System.out.println(nameElement.asXML());
      System.out.println(nameElement.getText());
//getText(); 可以获取标签中的文本内容
//elementText() 可以获取标签中的内容
//直接获取属性中的值
      String sn = student.attributeValue("banji");
      String name = student.elementText("name");
      int age = Integer.parseInt(student.elementText("age"));
      String number = student.elementText("number");
      }
    } catch (DocumentException e) {
      e.printStackTrace();
   }
 }
}