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：
  1 import java.io.File;
  2 import java.io.FileWriter;
  3 import java.io.IOException;
  4 import java.util.ArrayList;
  5 import java.util.List;
  6 
  7 import org.dom4j.Document;
  8 import org.dom4j.DocumentException;
  9 import org.dom4j.DocumentHelper;
 10 import org.dom4j.Element;
 11 import org.dom4j.io.OutputFormat;
 12 import org.dom4j.io.SAXReader;
 13 import org.dom4j.io.XMLWriter;
 14 
 15 
 16 public class HandleXML {
 17 
 18     
 19     public static void main(String[] args) {
 20         // TODO Auto-generated method stub
 21         
 22         SAXReader reader = new SAXReader();
 23         reader.setEncoding("gb2312");  
 24         Document document;
 25         List serviceSystems = new ArrayList<ServiceSystem>();
 26         List list1,list2,list3;
 27         List serverList = new ArrayList();
 28         List ServerTypeList = new ArrayList();
 29         List ServiceSystemList = new ArrayList();
 30         try {
 31             document = reader.read(new File("E:\\serviceSystem.xml"));
 32             Element rootElm = document.getRootElement();
 33             list1 = (List)rootElm.elements();
 34             for(Object oj0:list1){
 35                 Element element1 = (Element) oj0;
 36                 ServiceSystem s = new ServiceSystem();
 37                 s.systemName = element1.element("systemName").getText();
 38                 list2 = new ArrayList<ServerType>();
 39                 list2 = element1.elements("type");
 40                 for(Object oj1:list2){
 41                     Element element2 = (Element)oj1;
 42                     ServerType type = new ServerType();
 43                     type.typeName = element2.element("typeName").getText();
 44                     list3 = (List)element2.elements("server");
 45                     for(Object oj:list3){
 46                         Element element3 = (Element)oj;
 47                         Server server = new Server();
 48                         server.serverName = element3.element("serverName").getText();
 49                         server.vmName = element3.element("vmName").getText();
 50                         server.desc = element3.element("desc").getText();
 51                         serverList.add(server);
 52                         type.servers.add(server);
 53                     }
 54                     
 55                     
 56                     s.serverTypes.add(type);
 57                 }
 58                 ServiceSystemList.add(s);
 59             }
 60             serviceSystems = ServiceSystemList;
 61         } catch (DocumentException e) {
 62             // TODO Auto-generated catch block
 63             e.printStackTrace();
 64         }
 65         
 66         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     }
114     
115 
116 
117 
118 }