JDOM解析XML

package com.yujie.xml;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

/**
 * JDom操作xml文件工具 

1、创建的user.xml 

<?xml version="1.0" encoding="utf-8"?> 
<list> 
<user id="0"> 
<name>小鱼0</name> 
<age>28</age> 
<email>0106789@163.com</email> 
</user> 
<user id="1"> 
<name>小鱼1</name> 
<age>26</age> 
<email>0106789@163.com</email> 
</user> 
<user id="2"> 
<name>小鱼2</name> 
<age>26</age> 
<email>0106789@163.com</email> 
</user> 
</list> 

2追加后的user.xml 

<?xml version="1.0" encoding="gb2312"?> 
<list> 
<user id="0"> 
<name>小鱼0</name> 
<age>26</age> 
<email>0106789@163.com</email> 
</user> 
<user id="1"> 
<name>小鱼1</name> 
<age>26</age> 
<email>0106789@163.com</email> 
</user> 
<user id="2"> 
<name>小鱼2</name> 
<age>26</age> 
<email>0106789@163.com</email> 
</user> 
<user id="3"> 
<name>刘德华</name> 
<age>48</age> 
<email>AndyLiu@126.com</email> 
</user> 
</list> 

 * @author Administrator
 *
 */
public class JDom {
    // 创建XML
    public void BuildXMLDoc() throws IOException, JDOMException {
        // 创建根节点 root;
        Element root = new Element("list");
        // 根节点添加到文档中；
        Document Doc = new Document(root);
        // 此处 for 循环可替换成 遍历 数据库表的结果集操作;
        for (int i = 0; i < 3; i++) {
            // 创建节点 user;
            Element elements = new Element("user");
            // 给 user 节点添加属性 id;
            elements.setAttribute("id", "" + i);
            // 给 user 节点添加子节点并赋值；
            elements.addContent(new Element("name").setText("小鱼"+String.valueOf(i)));
            elements.addContent(new Element("age").setText("26"));
            elements.addContent(new Element("email").setText("0106789@163.com"));

            // 给父节点list添加user子节点;
            root.addContent(elements);
        }
        // 定义输出
        XMLOutputter XMLOut = new XMLOutputter();
        // 设置格式
        Format format = Format.getPrettyFormat();
        format.setEncoding("utf-8"); // 设置xml文件的字符为gb2312
        format.setIndent(" "); // 设置xml文件的缩进为4个空格

        XMLOut.setFormat(format);
        // 输出 user.xml 文件；
        XMLOut.output(Doc, new FileOutputStream("user.xml"));
    }

    // 读XML节点数据
    public void ReadXMLDoc() throws IOException, JDOMException {
        /** ***********将user.xml个别节点读出显示**************** */
        File fn = new File("user.xml");
        Document doc = null;
        // 建立构造器
        SAXBuilder sb = new SAXBuilder();
        // 判断文件是否存在
        if (fn.exists()) {
            try {
                // 读入指定文件
                doc = sb.build(new FileInputStream("user.xml"));
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
            // 获得根结点
            Element root = doc.getRootElement();
            // 将根结点下的所有子节点放入List中
            List list = root.getChildren();

            for (int i = 0; i < list.size(); i++) {
                System.out.println("-----------------------");
                // 取得节点实例
                Element item = (Element) list.get(i);
                // 取得当前节点的子节点
                String sid = item.getAttribute("id").getValue();// 取得属性值
                System.out.println("id:" + sid);

                Element Name = item.getChild("name");
                String sname = Name.getText();// 取得当前节点的值
                System.out.println("Name:" + sname);
            }
        } else {
            System.out.println("Not found child element!");
        }

        /*
         * 将user.xml内容在控制台显示 //建立构造器 SAXBuilder builder = new SAXBuilder();
         * Document doc = null; //读入指定文件 doc = builder.build(new
         * FileInputStream("user.xml")); XMLOutputter fmt = new XMLOutputter();
         * Format format = Format.getPrettyFormat();
         * format.setEncoding("gb2312"); //设置xml文件的字符为gb2312 format.setIndent("
         * "); //设置xml文件的缩进为4个空格 fmt.setFormat(format); PrintWriter out=new
         * PrintWriter(System.out); //不加 中文会乱码 fmt.output(doc, out);
         */

    }

    // 在XML文件尾部追加
    public void AddXMLDoc() throws IOException, JDOMException {
        File fn = new File("user.xml");
        Document doc = null;
        SAXBuilder sb = new SAXBuilder();
        // 如果文件存在
        if (fn.exists()) {
            try {
                doc = sb.build(new FileInputStream("user.xml"));
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }

            Element root = doc.getRootElement();
            if (root.getContentSize() > 0) {
                List list = root.getChildren();
                Element elements = new Element("user");
                // 给 user 节点添加属性 id;
                elements.setAttribute("id", "" + list.size());
                elements.addContent(new Element("name").setText("刘德华"));
                elements.addContent(new Element("age").setText("48"));
                elements.addContent(new Element("email")
                        .setText("AndyLiu@126.com"));

                // 给父节点list添加user子节点;
                root.addContent(elements);
                // 设置输出格式
                Format f = Format.getPrettyFormat();
                f.setIndent(" ");
                f.setEncoding("utf-8");
                XMLOutputter output = new XMLOutputter(f);
                try {
                    output.output(doc, new FileOutputStream("user.xml"));
                } catch (Exception e) {
                    System.out.println(e.getMessage());
                }
            }
            // 如果文件不存在
            else {
                System.out.println("Not found child element!");
            }

        } else {
            System.out.println("找不到指定的文件！");
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        try {
            JDom jdom = new JDom();
            jdom.BuildXMLDoc(); //创建
            // jdom.AddXMLDoc(); //追加
            jdom.ReadXMLDoc();// 读取
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}