DOM4J Parsing xml

Now there are a lot of toolkit to parse XML files, but dom4j is undoubtedly one of the simpler, here is an example to actually operate:

First you have to import Dom4j.jar this clip (online search a large)

1. Create a user.xml file in one place, which I am building in the D Packing directory:

 

2. <? XML version= "1.0" encoding="UTF-8"?>
6. <users>
8. <user username= "Lisi" password="123"/>
10. <user username= "Zhang San" password="123"/>
12. <user username= "zhangsan" password="123"/>
16. </users>

<?xml version= "1.0" encoding= "UTF-8"? ><users><user username= "Lisi" password= "123"/><user Username= "Zhang San" password= "123"/><user username= "Zhangsan" password= "123"/></users>

2. Impersonate the file to query the user (query by name) and add Users:

 

2. Package Com.easyteam.dao;
6. Import java.io.FileNotFoundException;
8. Import Java.io.FileOutputStream;
10. Import java.io.IOException;
12. Import Java.io.OutputStream;
14. Import Java.io.OutputStreamWriter;
16. Import java.io.UnsupportedEncodingException;
20. Import org.dom4j.Document;
22. Import org.dom4j.DocumentException;
24. Import org.dom4j.Element;
26. Import Org.dom4j.io.OutputFormat;
28. Import Org.dom4j.io.SAXReader;
30. Import Org.dom4j.io.XMLWriter;
34. Import Com.easyteam.domain.User;
40. Public class Userdao {
44. String path="D://user.xml";
48. Public User Findbyname (String username) {
50. Saxreader red=New Saxreader (); Creating a parser
52. try {
54. Document doc=red.read (path); //Get Documet object
56. Element el= (Element) Doc.selectsinglenode ("//user[@username = '" +username+"']");//Query condition, where//denotes infinite depth query, [] Put in is a query condition
58. if (el==null) return null;
60. String attusername=el.attributevalue ("username"); Get the value of username this property
62. String attpassword=el.attributevalue ("password");
64. User user=New user ();
66. User.setusername (Attusername);
68. User.setpassword (Attpassword);
70. return user;
72. } catch (Documentexception e) {
74. throw New RuntimeException (e);
76. }
78. }
80. public void AddUser (user user) {
84. Saxreader red=New Saxreader ();
86. try {
88. Document doc = red.read (path);
90. Element attroot=doc.getrootelement (); //Get root node
92. Element userel=attroot.addelement ("user"); Adding nodes
94. Userel.addattribute ("username", user.getusername ()); Assigning a value to a new node
96. Userel.addattribute ("Password", User.getpassword ());
100. OutputFormat format=New OutputFormat ("\ T", true); Set format
102. Format.settrimtext (true); Clear original format
104. XMLWriter writer;
106. try {
108. writer=New XMLWriter (New OutputStreamWriter (NewFileOutputStream (path),"Utf-8"), format); Instantiation of
110. Writer.write (DOC); //Save
112. Writer.close ();
114. } catch (Exception e) {
116. throw New RuntimeException (e);
118. }
122. } catch (Documentexception e) {
124. throw New RuntimeException (e);
126. }
128. }
130. }

3. Test class:

 

2. Package com.easyteam.test;
6. Import Org.junit.Test;
10. Import Com.easyteam.dao.Userdao;
12. Import Com.easyteam.domain.User;
18. Public class Userdaotest {
20. @Test
24. Public void Testfindbyname () {
26. Userdao dao=New Userdao ();
28. User user= dao.findbyname ("Lisi");
30. SYSTEM.OUT.PRINTLN (user);
34. }
36. @Test
38. Public void Testadduser () {
40. Userdao dao=New Userdao ();
42. User user=New user ();
44. User.setusername ("Zhang San");
46. User.setpassword ("123");
48. Dao.adduser (user);
56. }
58. }

DOM4J Parsing xml