JavaWeb——XML入门（二）

package com.imooc.dom4j;
import java.util.List;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class HrReader {
  //读取XML文件方法
  public void readXml(){
  String file = "/Users/lcs/eclipse-workspace/xml/src/hr.xml";
  //SAXReader类是读取XML文件的核心类，用于将XML解析后以“树”的形式保存在内存中
  SAXReader reader = new SAXReader(); 
  try {
    Document document = reader.read(file);
    //获取XML文档的根节点，即hr标签
    Element root = document.getRootElement();
    //elements方法用于获取指定的标签集合
    List<Element> employees = root.elements("employee");
    for(Element employee:employees) {
    //element()用于获取唯一的子节点对象
    Element name = employee.element("name");
    //getText()标签用于获取标签文本 
    String empName = name.getText();
    System.out.print(empName);
    //获取属性
    Attribute att = employee.attribute("no");
    System.out.println("  工号："+att.getText()); 
    System.out.println(employee.elementText("age"));
    System.out.println(employee.elementText("salary"));
    Element department = employee.element("department");
    System.out.println(department.element("dname").getText());
    System.out.println(department.element("address").getText());
    System.out.println("================");
    }
  } catch (DocumentException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
  }
  public static void main(String[] args) {
  HrReader reader = new HrReader();
  reader.readXml();
  }
}

张三  工号：3309
30
4000
会计部
XX-大厦-B103
================
莉丝  工号：3310
30
5000
工厂部
XX-大厦-B104
================

package com.imooc.dom4j;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class HrWriter {
  public void writeXml() {
  String file = "/Users/lcs/eclipse-workspace/xml/src/hr.xml";
  // SAXReader类是读取XML文件的核心类，用于将XML解析后以“树”的形式保存在内存中
  SAXReader reader = new SAXReader();
  try {
    Document document = reader.read(file);
    // 获取XML文档的根节点，即hr标签
    Element root = document.getRootElement();
    // addElement()方法用于创造一个传入参数类型的元素
    Element employee = root.addElement("employee");
    // 然后在新建的employee上增加属性
    employee.addAttribute("no", "3311");
    // 增加子节点
    Element name = employee.addElement("name");
    name.setText("王五");
    employee.addElement("age").setText("37");
    employee.addElement("salary").setText("9000");
    Element department = employee.addElement("department");
    department.addElement("dname").setText("人事部");
    department.addElement("address").setText("XX-大厦-A108");
    // 已经在内存中完成了编写，接下来将其导入到XML文件
    Writer writer = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
    document.write(writer);
    writer.close();
  } catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
  }
  public static void main(String[] args) {
  HrWriter hrWriter = new HrWriter();
  hrWriter.writeXml();
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hr SYSTEM "hr.dtd"><!-- 人力资源管理系统 -->
<hr>
  <employee no="3309">
  <name>张三</name>
  <age>30</age>
  <salary>4000</salary>
  <department>
    <dname>会计部</dname>
    <address>XX-大厦-B103</address>
  </department>
  </employee>
  <employee no="3310">
  <name>莉丝</name>
  <age>30</age>
  <salary>5000</salary>
  <department>
    <dname>工厂部</dname>
    <address>XX-大厦-B104</address>
  </department>
  </employee>
  <employee no="3311">
  <name>王五</name>
  <age>37</age>
  <salary>9000</salary>
  <department>
    <dname>人事部</dname>
    <address>XX-大厦-A108</address>
  </department>
  </employee>
</hr>

package com.imooc.dom4j;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class Plan2Writer {
  public void writeXml() {
  String file = "/Users/lcs/eclipse-workspace/xml/src/plan2.xml";
  // SAXReader类是读取XML文件的核心类，用于将XML解析后以“树”的形式保存在内存中
  SAXReader reader = new SAXReader();
  try {
    Document document = reader.read(file);
    // 获取XML文档的根节点，即course标签
    Element root = document.getRootElement();
    // addElement()方法用于创造一个传入参数类型的元素
    Element employee = root.addElement("course");
    // 增加子节点
    Element name = employee.addElement("course-name");
    name.setText("历史");
    employee.addElement("class-hour").setText("50");
    employee.addElement("exam-form").setText("考试");
    // 已经在内存中完成了编写，接下来将其导入到XML文件
    Writer writer = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
    document.write(writer);
    writer.close();
  } catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
  }
  public static void main(String[] args) {
  Plan2Writer plan2Writer = new Plan2Writer();
  plan2Writer.writeXml();
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plan SYSTEM "plan.dtd">
<teaching-plan>
  <course>
  <course-name>大学英语</course-name>
  <class-hour>36</class-hour>
  <exam-form>考试</exam-form>
  </course>
  <course>
  <course-name>高等数学</course-name>
  <class-hour>70</class-hour>
  <exam-form>考试</exam-form>
  </course>
  <course>
  <course-name>计算机应用基础</course-name>
  <class-hour>108</class-hour>
  <exam-form>上机考试</exam-form>
  </course>
  <course>
  <course-name>历史</course-name>
  <class-hour>50</class-hour>
  <exam-form>考试</exam-form>
  </course>
</teaching-plan>

//第一个/表示xml文件,其它/表示分隔符; 
String xpath = "/电视/a/b/c/d";
Element dElement = (Element) xmlDocument.selectStringleNOde();
List<Element> list = xmlDocument.selectNodes(xpath);