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Dom4j 操作， 节点查找 添加 删除 修改 。。。xPath

Dom4j 说明文档：http://blog.csdn.net/xj626852095/article/details/17000741

xPath说明文档： http://www.zvon.org/xxl/XPathTutorial/General_chi/examples.html

要解析的xml文件

1. <?xml version="1.0" encoding="UTF-8"?>
2.  
3. <书架>
4. <书 name="yyyyyyy">
5. <书名>Java</书名>
6. <作者>张三</作者>
7. <打折价>9.9折</打折价>
8. <售价>只要998</售价>
9. </书>
10. <书 memony="有优惠价">
11. <书名 name="xxxxx">JavaScript网页开发</书名>
12. <作者>李四</作者>
13. <售价>28.00元</售价>
14. <优惠价>8折</优惠价>
15. <优惠价>8折</优惠价>
16. <优惠价>8折</优惠价>
17. </书>
18. <user username="kevin" passwd="123456"/>
19. <user username="xiang" passwd="234567"/>
20. </书架>

1. package com.kevin.java;
2.  
3. import static org.junit.Assert.*;
4.  
5. import java.io.File;
6. import java.io.FileOutputStream;
7. import java.io.FileWriter;
8. import java.io.IOException;
9. import java.io.OutputStreamWriter;
10. import java.util.List;
11.  
12. import org.dom4j.Document;
13. import org.dom4j.DocumentException;
14. import org.dom4j.DocumentHelper;
15. import org.dom4j.Element;
16. import org.dom4j.Node;
17. import org.dom4j.io.OutputFormat;
18. import org.dom4j.io.SAXReader;
19. import org.dom4j.io.XMLWriter;
20. import org.junit.Test;
21. import org.xml.sax.DocumentHandler;
22.  
23. public class Dom4j_Test {
24.  
25. //Xpath使用
26. @Test
27. public void test4() throws DocumentException, IOException {
28. SAXReader reader = new SAXReader();
29. Document document = reader.read(new File("src/book1.xml"));
30. String bookName = document.selectSingleNode("//书名").getText();
31. System.out.println("bookName: " + bookName);
32.  
33. //查找符合条件的User //BBB[@id=‘b1‘] 注意要有单引号
34. String username = "kevin";
35. String passwd = "123456";
36. Node node = document.selectSingleNode
37. ("//user[@username=‘"+username+"‘ and @passwd=‘"+passwd+"‘]");
38. if(node==null)
39. System.out.println("不是注册用户");
40. else
41. System.out.println("注册用户");
42.  
43. }
44.  
45. //获得第二本数的书名, 属性值 ， 添加售价节点
46. @Test
47. public void test1() throws DocumentException, IOException {
48. SAXReader reader = new SAXReader();
49. Document document = reader.read(new File("src/book1.xml"));
50. Element root = document.getRootElement();
51. Element book = root.elements("书").get(1);
52. String bookName = book.element("书名").getText();
53. String bookAttr = book.element("书名").attributeValue("name");
54. System.out.println("bookName: " + bookName);
55. System.out.println("bookAttr: " + bookAttr);
56.  
57. //添加售价节点
58. book.addAttribute("memony", "有优惠价");
59. book.addElement("优惠价").setText("8折");
60. OutputFormat format = OutputFormat.createPrettyPrint();
61. format.setEncoding("UTF-8");
62. XMLWriter writer = new XMLWriter(
63. new OutputStreamWriter(new FileOutputStream("src/book1.xml")), format);
64. writer.write(document);
65. writer.close();
66. }
67.  
68. //指定位置添加
69. @Test
70. public void test2() throws DocumentException, IOException {
71. SAXReader reader = new SAXReader();
72. Document document = reader.read(new File("src/book1.xml"));
73. Element book = document.getRootElement().element("书");
74. List list = book.elements();
75.  
76. Element price = DocumentHelper.createElement("打折价");
77. price.setText("9.9折");
78. list.add(2, price);
79.  
80. OutputFormat format = OutputFormat.createPrettyPrint();
81. format.setEncoding("UTF-8");
82. XMLWriter writer = new XMLWriter(
83. new OutputStreamWriter(new FileOutputStream("src/book1.xml")), format);
84. writer.write(document);
85. writer.close();
86. }
87.  
88. //删除节点 更新节点
89. @Test
90. public void test3() throws DocumentException, IOException {
91. SAXReader reader = new SAXReader();
92. Document document = reader.read(new File("src/book1.xml"));
93. Element priceTmp = document.getRootElement().element("书").element("打折价");
94. //删除节点
95. priceTmp.getParent().remove(priceTmp);
96.  
97. Element price = document.getRootElement().element("书").element("售价");
98. //更新节点
99. price.setText("只要998");
100.  
101. OutputFormat format = OutputFormat.createPrettyPrint();
102. format.setEncoding("UTF-8");
103. XMLWriter writer = new XMLWriter(
104. new OutputStreamWriter(new FileOutputStream("src/book1.xml")), format);
105. writer.write(document);
106. writer.close();
107. }
108.  

Dom4j 操作， 节点查找 添加 删除 修改 。。。xPath

原文：https://www.cnblogs.com/libin6505/p/10120468.html