应用dom4j读写xml范例

 最近在研究开源软件“局域网聊天工具 Net-C”，项目主页为http://dgtalize.com/products/netc，里面有几段代码是用dom4j来读写xml文件的，本人使用较新的dom4j2.0改写了其中的这段代码。

xml文件为：

config.xml

1. <?xml version="1.0" encoding="UTF-8"?> 
2. <!-- 
3.     Document   : config.xml 
4.     Created on : 19 de marzo de 2008, 22:37 
5.     Author     : Diego 
6.     Description: Configuration file por Net-C 
7. --><config> 
8.     <param> 
9.         <name>ipBroadcast</name> 
10.         <value>192.168.255.255</value> 
11.     </param> 
12.     <param> 
13.         <name>portBroadcast</name> 
14.         <value>41516</value> 
15.     </param> 
16.     <param> 
17.         <name>portPrivateChat</name> 
18.         <value>41518</value> 
19.     </param> 
20.     <param> 
21.         <name>nickname</name> 
22.         <value>robbie</value> 
23.     </param> 
24.     <param> 
25.         <name>trayMsgUserLogged</name> 
26.         <value>true</value> 
27.     </param> 
28.     <param> 
29.         <name>trayMsgUserLoggedOff</name> 
30.         <value>false</value> 
31.     </param> 
32.     <param> 
33.         <name>trayMsgPrivateMsg</name> 
34.         <value>true</value> 
35.     </param> 
36.     <param> 
37.         <name>useNativeUI</name> 
38.         <value>true</value> 
39.     </param> 
40.     <param> 
41.         <name>startMinimized</name> 
42.         <value>false</value> 
43.     </param> 
44. </config> 
    

得到上述xml文档的Document对象的代码为

 

1. private Document getConfigDocument() throws Exception { 
2.         if (configDoc == null) { 
3.             File cfgFile = new File(filePath); 
4.             if (!cfgFile.exists()) { 
5.  
6.                 cfgFile.createNewFile(); 
7.                 try { 
8.                     //FileInputStream fis = new FileInputStream(cfgFileOrig); 
9.                     InputStream fis = getClass().getResourceAsStream("/com/dgtalize/netc/business/config.xml"); 
10.                     FileOutputStream fos = new FileOutputStream(cfgFile); 
11.                     byte[] buf = new byte[1024]; 
12.                     int readCant = 0; 
13.                     while ((readCant = fis.read(buf)) != -1) { 
14.                         fos.write(buf, 0, readCant); 
15.                     } 
16.                     fis.close(); 
17.                     fos.close(); 
18.                 } catch (Exception ex) { 
19.                     cfgFile.delete(); 
20.                     throw ex; 
21.                 } 
22.             } 
23.  
24.             SAXReader reader = new SAXReader(); 
25.             configDoc = reader.read(new File(filePath)); 
26.             configDoc.normalize(); 
27.         } 
28.         return configDoc; 
29.     } 

读取里面的参数(param)元素到变量的代码为：

 

1. public void readConfigFile() throws Exception { 
2.         configDoc = getConfigDocument(); 
3.         Element rootElement = configDoc.getRootElement(); 
4.         Iterator<Element> it = rootElement.elementIterator("param"); 
5.         while (it.hasNext()) { 
6.             Element element = it.next(); 
7.             String name = element.elementIterator("name").next().getTextTrim(); 
8.             String value = element.elementIterator("value").next().getTextTrim(); 
9.             if (name.equalsIgnoreCase("ipBroadcast")) { 
10.                 ipBroadcast = value; 
11.             } else if (name.equalsIgnoreCase("portBroadcast")) { 
12.                 portBroadcast = Integer.parseInt(value); 
13.             } else if (name.equalsIgnoreCase("nickname")) { 
14.                 nickname = value == null ? "" : value; 
15.             } else if (name.equalsIgnoreCase("portPrivateChat")) { 
16.                 portPrivateChat = Integer.parseInt(value); 
17.             } else if (name.equalsIgnoreCase("trayMsgUserLogged")) { 
18.                 trayMsgUserLogged = Boolean.parseBoolean(value); 
19.             } else if (name.equalsIgnoreCase("trayMsgPrivateMsg")) { 
20.                 trayMsgPrivateMsg = Boolean.parseBoolean(value); 
21.             } else if (name.equalsIgnoreCase("trayMsgUserLoggedOff")) { 
22.                 trayMsgUserLoggedOff = Boolean.parseBoolean(value); 
23.             } else if (name.equalsIgnoreCase("useNativeUI")) { 
24.                 useNativeUI = Boolean.parseBoolean(value); 
25.             } else if (name.equalsIgnoreCase("startMinimized")) { 
26.                 startMinimized = Boolean.parseBoolean(value); 
27.             } 
28.         } 
29.  
30.     } 

根据里面的私有变量保存xml文件的代码为：

 

1. public void saveConfigFile() throws Exception { 
2.         Document configDocForSave = getConfigDocument(); 
3.  
4.         Element rootElement = configDocForSave.getRootElement(); 
5.         Iterator<Element> it = rootElement.elementIterator("param"); 
6.         while (it.hasNext()) { 
7.             Element element = it.next(); 
8.             Element nextName = element.elementIterator("name").next(); 
9.             String name = nextName.getTextTrim(); 
10.             Element nextValue = element.elementIterator("value").next(); 
11.             String value = nextValue.getTextTrim(); 
12.             if (name.equalsIgnoreCase("ipBroadcast")) { 
13.                 nextValue.setText(ipBroadcast); 
14.             } else if (name.equalsIgnoreCase("portBroadcast")) { 
15.                 nextValue.setText(String.valueOf(portBroadcast)); 
16.             } else if (name.equalsIgnoreCase("nickname")) { 
17.                 nextValue.setText(nickname); 
18.             } else if (name.equalsIgnoreCase("portPrivateChat")) { 
19.                 nextValue.setText(String.valueOf(portPrivateChat)); 
20.             } else if (name.equalsIgnoreCase("trayMsgUserLogged")) { 
21.                 nextValue.setText(String.valueOf(trayMsgUserLogged)); 
22.             } else if (name.equalsIgnoreCase("trayMsgPrivateMsg")) { 
23.                 nextValue.setText(String.valueOf(trayMsgPrivateMsg)); 
24.             } else if (name.equalsIgnoreCase("trayMsgUserLoggedOff")) { 
25.                 nextValue.setText(String.valueOf(trayMsgUserLoggedOff)); 
26.                 trayMsgUserLoggedOff = Boolean.parseBoolean(value); 
27.             } else if (name.equalsIgnoreCase("useNativeUI")) { 
28.                 nextValue.setText(String.valueOf(useNativeUI)); 
29.             } else if (name.equalsIgnoreCase("startMinimized")) { 
30.                 nextValue.setText(String.valueOf(startMinimized)); 
31.             } 
32.         } 
33.         XMLWriter writer = new XMLWriter(new FileWriter(filePath)); 
34.         writer.write(configDocForSave); 
35.         writer.close(); 
36.  
37.     } 

 

转载于:https://blog.51cto.com/robbietree/274904