用dom4j生成xml以及读取xml文件里内容

老丁 — Mon, 08 Sep 2008 12:16:00 GMT

首先去下载dom4j的jar包，新建WEB工程，将jar包加到工程当中

准备一个操作类 FindXmlDoc.java

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class FindXmlDoc {

/**
  *
  *   @Description 创建xml文件
  *   @param filename
  *   @param rootElement
  *   void
  *   @throws  抛出异常说明
  */
public void createXMLFile(String filename,String rootElement) {

  /** 建立document对象 */
  Document document = DocumentHelper.createDocument();


  document.addElement(rootElement);
  try {

   /** 将document中的内容写入文件中 */

   XMLWriter writer = new XMLWriter(new FileWriter(new File(filename)));

   writer.write(document);

   writer.close();

  } catch (Exception ex) {

  }

}

/**
  *
  *   @Description 保存编辑的XML文件
  *   @param document
  *   @param filepath
  *   @return
  *   boolean
  *   @throws  抛出异常说明
  */
public boolean saveDocument(Document document,String filepath) {
  boolean isOk = false;
  Writer writer = null;
  XMLWriter xmlWriter = null;
  try {
   writer = new OutputStreamWriter(new FileOutputStream(filepath),"utf-8");
   OutputFormat format = OutputFormat.createPrettyPrint();
   format.setEncoding("utf-8");
   xmlWriter = new XMLWriter(writer,format);
   xmlWriter.write(document);
   writer.close();
   isOk = true;
  } catch (IOException e) {

   return false;
  }
  return isOk;
}

/**
  *
  *   @Description 获取XML文件中的信息,如果文件存在,返回document，如果不存在,返回null
  *   @param filepath
  *   @return
  *   Document
  *   @throws  抛出异常说明
  */
public Document getDocument(String filepath) {
  Document document = null;
  SAXReader reader = new SAXReader();
  try {
   File file = new File(filepath);
   if(file.exists()){
    document = reader.read(file);//不是以UTF-8来读取。要换成以UTF——8来读取

   }else{
    return null;
   }
  } catch (Exception e) {

  }
  return document;
}
}

下面是测试类

public class TestCreateXML {
  public static void main(String[] args) {

     TestCreateXML.createXML();
}

public static void createXML(){
  FindXmlDoc fxd = new FindXmlDoc();
  fxd.createXMLFile("teacher.xml", "teacher");
}
}

执行这个类就会在webroot下生成teacher.xml文件
内容如下：

xml version="1.0" encoding="utf-8"?>

<teacher/>

这个是只有一个根节点的xml文件。
下面来加点东西
修改createXML方法为如下：

public static void createXML(){
  FindXmlDoc fxd = new FindXmlDoc();
  String path ="teacher.xml";
  Document document = fxd.getDocument(path);
  Element rootElement = document.getRootElement();
  Element student1Element = rootElement.addElement("student1");
  Element student1name = student1Element.addElement("name");
  Element student1class = student1Element.addElement("class");
  student1name.addText("ding");
  student1class.addText("040931");
  Element student2Element = rootElement.addElement("student2");
  Element student2name = student2Element.addElement("name");
  Element student2class = student2Element.addElement("class");
  student2name.addText("laoding");
  student2class.addText("040931");
  fxd.saveDocument(document, path);
  System.out.println("success");
}

执行看到后台打印出success

此时发现teacher.xml变成了以下样子

xml version="1.0" encoding="utf-8"?>

<teacher>
  <student1>
    <name>dingname>
    <class>040931class>
  student1>
  <student2>
    <name>laodingname>
    <class>040931class>
  student2>
teacher>

这就完成生成xml的操作了

下面是读取xml文件

public static void readXML(){
  FindXmlDoc fxd = new FindXmlDoc();
  String path ="teacher.xml";
  Document document = fxd.getDocument(path);
  Element rootElement = document.getRootElement();

  Element student = rootElement.element("student1");
  System.out.println(student.getName());
  List l = student.elements();
  for(int i = 0; i < l.size(); i++){
   Element e= (Element)l.get(i);
   System.out.println(e.getText());
  }
}

执行这个方法，后台打印出

student1
ding
040931

可以看到读取到节点student1以及这个节点下的内容

将Element student = rootElement.element("student1");这里的student1改成student2

执行看到

student2
laoding
040931

好了，完成了，有什么疑问，欢迎交流

老丁 2008-09-08 20:16 发表评论

BlogJava-laoding-文章分类-xml

用dom4j生成xml以及读取xml文件里内容