Java讀寫XML文件

需要讀取的XML文件：

<?xml version=”1.0″ encoding=”utf-8″?>
<學生花名冊>
<學生 性別 = “男”>
<姓名>李華</姓名>
<年齡>14</年齡>
</學生>
<學生 性別 = “男”>
<姓名>張三</姓名>
<年齡>16</年齡>
</學生>
</學生花名冊>

把該內容拷貝到student.xml中，存放到E盤下即可。

XMLDemo.java文件：

1. import java.io.FileOutputStream;
2. import java.io.OutputStreamWriter;
3. import java.io.Writer;
4. import java.util.ArrayList;
5. import java.util.Iterator;
6. import javax.xml.parsers.DocumentBuilder;
7. import javax.xml.parsers.DocumentBuilderFactory;
8. import javax.xml.transform.OutputKeys;
9. import javax.xml.transform.Result;
10. import javax.xml.transform.Source;
11. import javax.xml.transform.Transformer;
12. import javax.xml.transform.TransformerConfigurationException;
13. import javax.xml.transform.TransformerException;
14. import javax.xml.transform.TransformerFactory;
15. import javax.xml.transform.dom.DOMSource;
16. import javax.xml.transform.stream.StreamResult;
17. import org.w3c.dom.Document;
18. import org.w3c.dom.Element;
19. import org.w3c.dom.Node;
20. import org.w3c.dom.NodeList;
21. import org.w3c.dom.Text;
22. public class XMLDemo {
23. ArrayList<Student> students_al=null;
24. private ArrayList<Student> readXMLFile(String file) throws Exception {
25. DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
26. DocumentBuilder builder = dbf.newDocumentBuilder();
27. Document doc = builder.parse(file); // 獲取到xml文件
28. // 下面開始讀取
29. Element root = doc.getDocumentElement(); // 獲取根元素
30. NodeList students = root.getElementsByTagName(“學生”);
31. students_al = new ArrayList<Student>();
32. for (int i = 0; i < students.getLength(); i++) {
33. // 一次取得每一個學生元素
34. Element ss = (Element) students.item(i);
35. // 創建一個學生的實例
36. Student stu = new Student();
37. stu.setSex(ss.getAttribute(“性別”));
38. NodeList names = ss.getElementsByTagName(“姓名”);
39. Element e = (Element) names.item(0);
40. Node t = e.getFirstChild();
41. stu.setName(t.getNodeValue());
42. NodeList ages = ss.getElementsByTagName(“年齡”);
43. e = (Element) ages.item(0);
44. t = e.getFirstChild();
45. stu.setAge(Integer.parseInt(t.getNodeValue()));
46. students_al.add(stu);
47. }
48. return students_al;
49. }
50. // 寫入ｘｍｌ文件
51. public static void callWriteXmlFile(Document doc, Writer w, String encoding) {
52. try {
53. Source source = new DOMSource(doc);
54. Result result = new StreamResult(w);
55. Transformer xformer = TransformerFactory.newInstance()
56. .newTransformer();
57. xformer.setOutputProperty(OutputKeys.ENCODING, encoding);
58. xformer.transform(source, result);
59. } catch (TransformerConfigurationException e) {
60. e.printStackTrace();
61. } catch (TransformerException e) {
62. e.printStackTrace();
63. }
64. }
65. private void writeXMLFile(String outfile) {
66. DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
67. DocumentBuilder builder = null;
68. try {
69. builder = dbf.newDocumentBuilder();
70. } catch (Exception e) {
71. }
72. Document doc = builder.newDocument();
73. Element root = doc.createElement(“學生花名冊”);
74. doc.appendChild(root); // 將根元素添加到文檔上
75. // 獲取學生信息
76. for (int i = 0; i < students_al.size(); i++) {
77. Student s = (Student) students_al.get(i);
78. // 創建一個學生
79. Element stu = doc.createElement(“學生”);
80. stu.setAttribute(“性別”, s.getSex());
81. root.appendChild(stu);// 添加屬性
82. // 創建文本姓名節點
83. Element name = doc.createElement(“姓名”);
84. stu.appendChild(name);
85. Text tname = doc.createTextNode(s.getName());
86. name.appendChild(tname);
87. // 創建文本年齡節點
88. Element age = doc.createElement(“年齡”);
89. stu.appendChild(age); // 將age添加到學生節點上
90. Text tage = doc.createTextNode(String.valueOf(s.getAge()));
91. age.appendChild(tage); // 將文本節點放在age節點上
92. }
93. try {
94. FileOutputStream fos = new FileOutputStream(outfile);
95. OutputStreamWriter outwriter = new OutputStreamWriter(fos);
96. // ((XmlDocument)doc).write(outwriter); //出錯！
97. callWriteXmlFile(doc, outwriter, “gbk”);
98. outwriter.close();
99. fos.close();
100. } catch (Exception e) {
101. e.printStackTrace();
102. }
103. }
104. public static void main(String args[]) {
105. String str = “E:/student.xml”;
106. XMLDemo t = new XMLDemo();
107. try {
108. ArrayList<Student> al = t.readXMLFile(str);
109. Iterator<Student> it = al.iterator();
110. while (it.hasNext()) {
111. Student s = (Student) it.next();
112. System.out.println(s.getName() + “\t” + s.getAge() + “\t”
113. + s.getSex());
114. }
115. } catch (Exception e) {
116. e.printStackTrace();
117. }
118. String outfile = “src/stucopy.xml”;
119. t.writeXMLFile(outfile);
120. }
121. }
122. class Student {
123. private String sex;
124. private String name;
125. private int age;
126. public int getAge() {
127. return age;
128. }
129. public void setAge(int age) {
130. this.age = age;
131. }
132. public void setSex(String s) {
133. sex = s;
134. }
135. public String getSex() {
136. return sex;
137. }
138. public void setName(String n) {
139. name = n;
140. }
141. public String getName() {
142. return name;
143. }
144. }