DOM4j读写XML（实例）

以下代码分为2部分：

第一部分 是上边黑色部分代码（即66行之前），完成的功能是读取XML中的内容，并将值保存到按XML的逻辑关系建成的类中。即将每个XML保存成一个类的实例。这里也体现了如何逐层解析XML文档。

第二部分 是下边的蓝色部分代码（即66行之后），完成的功能是将通过第一步得到的类的实例写入到一个XML文件中。这里体现了如何写XML。

具体代码如下：

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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


public class HandleXML {

    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        SAXReader reader = new SAXReader();
        reader.setEncoding("gb2312");  
        Document document;
        List serviceSystems = new ArrayList<ServiceSystem>();
        List list1,list2,list3;
        List serverList = new ArrayList();
        List ServerTypeList = new ArrayList();
        List ServiceSystemList = new ArrayList();
        try {
            document = reader.read(new File("E:\\serviceSystem.xml"));
            Element rootElm = document.getRootElement();
            list1 = (List)rootElm.elements();
            for(Object oj0:list1){
                Element element1 = (Element) oj0;
                ServiceSystem s = new ServiceSystem();
                s.systemName = element1.element("systemName").getText();
                list2 = new ArrayList<ServerType>();
                list2 = element1.elements("type");
                for(Object oj1:list2){
                    Element element2 = (Element)oj1;
                    ServerType type = new ServerType();
                    type.typeName = element2.element("typeName").getText();
                    list3 = (List)element2.elements("server");
                    for(Object oj:list3){
                        Element element3 = (Element)oj;
                        Server server = new Server();
                        server.serverName = element3.element("serverName").getText();
                        server.vmName = element3.element("vmName").getText();
                        server.desc = element3.element("desc").getText();
                        serverList.add(server);
                        type.servers.add(server);
                    }
                    
                    
                    s.serverTypes.add(type);
                }
                ServiceSystemList.add(s);
            }
            serviceSystems = ServiceSystemList;
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        XMLWriter writer = null;// 声明写XML的对象
 67 
 68         OutputFormat format = OutputFormat.createPrettyPrint();
 69         format.setEncoding("gb2312");// 设置XML文件的编码格式
 70 
 71         String filePath = "E:\\s.xml";
 72         File file = new File(filePath);
 73 
 74         Document _document = DocumentHelper.createDocument();
 75         Element _root = _document.addElement("serviceSystems");
 76 
 77         for(Object oj:serviceSystems){
 78             ServiceSystem s = (ServiceSystem)oj;
 79             Element _serviceSystem = _root.addElement("serviceSystem");
 80             List l1 = s.getServerTypes();
 81             Element _systemName = _serviceSystem.addElement("systemName");
 82             _systemName.setText(s.getSystemName());
 83             
 84             for(Object oj1:l1){
 85                 Element _type = _serviceSystem.addElement("type");
 86                 ServerType st = (ServerType)oj1;
 87                 List l2 = st.getServers();
 88                 Element _typeName = _type.addElement("typeName");
 89                 _typeName.setText(st.getTypeName());
 90                 
 91                 for(Object oj2:l2){
 92                     Element _server = _type.addElement("server");
 93                     Server ss = (Server)oj2;
 94                     Element _serverName = _server.addElement("serverName");
 95                     _serverName.setText(ss.getServerName());
 96                     Element _vmName = _server.addElement("vmName");
 97                     _vmName.setText(ss.getVmName());
 98                     Element _desc = _server.addElement("desc");
 99                     _desc.setText(ss.getDesc());
100                 }
101             }
102         }
103         
104         try {
105             writer = new XMLWriter(new FileWriter(file), format);
106             writer.write(_document);
107             writer.close();
108         } catch (IOException e) {
109             // TODO Auto-generated catch block
110             e.printStackTrace();
111         }
112         
113     }
    



}