第6章XML

1.编写XML文档

<?xml version="1.0" encoding="UTF-8"?>
<scores>
 <student id="1">
  <name>王二狗</name>
  <course>java课程</course>
  <score>85</score>
 </student>
 <student id="2">
  <name>李二牛</name>
  <course>C++</course>
  <score>89</score>
 </student>

</scores>

package com.bdqn.demo20180528;

/**
 * 2.使用DOM解析简答题1中编写XML文档,输出所有学员的信息
 */
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 AveInput {
 /**
  * 显示信息
  */
 public void xianshi() {
  DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
  try {
   DocumentBuilder builder = builderFactory.newDocumentBuilder();
   Document document = builder.parse("学员信息.xml");
   NodeList list = document.getElementsByTagName("student");
   for (int i = 0; i < list.getLength(); i++) {
    Node node = list.item(i);
    Element element = (Element) node;
    String string = element.getAttribute("id");
    System.out.println("编号:" + string);
    NodeList list2 = element.getElementsByTagName("name");
    NodeList list3 = element.getElementsByTagName("course");
    NodeList list4 = element.getElementsByTagName("score");
    for (int j = 0; j < list4.getLength(); j++) {
     Element element2 = (Element) list2.item(j);
     Element element3 = (Element) list3.item(j);
     Element element4 = (Element) list4.item(j);
     String name = element2.getFirstChild().getNodeValue();
     String cour = element3.getFirstChild().getNodeValue();
     String scor = element4.getFirstChild().getNodeValue();
     System.out.println("姓名:" + name + "\n课程:" + cour + "\n分数:" + scor);
    }
   }

  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

 public static void main(String[] args) {
  AveInput aveInput = new AveInput();
  // 显示学员信息
  aveInput.xianshi();

 }

}

package com.bdqn.demo20180528;
/**
 * 2.使用DOM解析简答题1保存成绩信息的XML做如下操作
 * 删除ID为1的成绩,修改ID为2的成绩为60,添加一个学生的成绩信息(ID为3)
 */
import java.io.FileOutputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Test {
 Document doc = null;
 
 public void load() {
  DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
  try {
   DocumentBuilder db = dbf.newDocumentBuilder();
   doc = db.parse("学员信息3.xml");
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
 
 /**
  * 删除id为1的成绩
  */
 public void delete() {
  NodeList list = doc.getElementsByTagName("student");
  for (int i = 0; i < list.getLength(); i++) {
   Node stu = list.item(i);
   Element element = (Element) stu;
   String str = element.getAttribute("id");
   if (str.equals("1")) {
    element.getParentNode().removeChild(element);
   }
  }
 }
 
 public void save() {
  TransformerFactory tff = TransformerFactory.newInstance();
  try {
   Transformer tf = tff.newTransformer();
   DOMSource doms = new DOMSource(doc);
   tf.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
   StreamResult result = new StreamResult(new FileOutputStream("学员信息3.xml"));
   tf.transform(doms, result);
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
 
 /**
  * 修改ID为2的成绩为60
  */
 public void change() {
  NodeList nl = doc.getElementsByTagName("student");
  for (int i = 0; i < nl.getLength(); i++) {
   Node stu = nl.item(i);
   Element element = (Element) stu;
   String str = element.getAttribute("id");
   if (str.equals("2")) {
    NodeList listScore = element.getElementsByTagName("score");
    Element getScore = (Element) listScore.item(0);
    getScore.setTextContent("60分");
   }
  }
 }
/**
 * 增加一个学员信息的成绩
 */
 public void add() {
  Element name = doc.createElement("name");
  name.setTextContent("刘二麻");
  Element course = doc.createElement("course");
  course.setTextContent("JAVA");
  Element score = doc.createElement("score");
  score.setTextContent("85分");
  Element student = doc.createElement("student");
  student.setAttribute("id", "3");
  student.appendChild(name);
  student.appendChild(course);
  student.appendChild(score);
  Element sorces = (Element) doc.getElementsByTagName("sorces").item(0);
  sorces.appendChild(student);
 }
 
 public static void main(String[] args) {
  Test test = new Test();
   test.load();
   test.delete();
   test.change();
   test.save();
   test.add();
   test.save();
 }
}

第4题   DOM4J解析第1题描述成绩信息的XML,输出成绩信息

import java.util.Iterator;


import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;


public class DOM4JScore {
public static void main(String[] args) {
SAXReader reader = new SAXReader();
Document doc = null;
try {
doc = reader.read("学员信息.xml");
Element root = doc.getRootElement();
for (Iterator iterator = root.elementIterator(); iterator.hasNext();) {
Element element = (Element) iterator.next();
String score = element.elementText("score");
System.out.println(score);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}