1 package itacst.dao;
2
3 import org.w3c.dom.Document;
4 import org.w3c.dom.Element;
5 import org.w3c.dom.Node;
6 import org.w3c.dom.NodeList;
7
8 import itacst.domain.Student;
9 import itacst.exception.StudentNotExistException;
10 import itacst.utils.XmlUtils;
11
12 public class StudentDao {
13
14 public void add(Student s){
15
16 try {
17 Document document = XmlUtils.getDocument();
18
19 //创建出封装学生信息的标签
20 Element student_tag = document.createElement("student");
21 student_tag.setAttribute("idcard", s.getIdcard());
22 student_tag.setAttribute("examid", s.getExamid());
23
24 //创建于封装学生姓名、所在地和成绩的标签
25 Element name = document.createElement("name");
26 Element location = document.createElement("location");
27 Element grade = document.createElement("grade");
28
29 name.setTextContent(s.getName());
30 location.setTextContent(s.getLocation());
31 grade.setTextContent(s.getGrade()+"");//任意东西加上字符串就变成字符串
32
33 student_tag.appendChild(name);
34 student_tag.appendChild(location);
35 student_tag.appendChild(grade);
36
37 //把封装了信息学生标签，挂到文档上
38 document.getElementsByTagName("exam").item(0).appendChild(student_tag);
39
40 //更新内存
41 XmlUtils.write2Xml(document);
42
43 } catch (Exception e) {
44 throw new RuntimeException(e);
45 //unchecked excpeiton(运行时异常)
46 }//checked exception(编译时的异常 )
47 }
48
49 public Student find(String examid){
50
51 try {
52 Document document = XmlUtils.getDocument();
53 NodeList list = document.getElementsByTagName("student");
54
55 for (int i = 0; i < list.getLength(); i++) {
56 Element student_tag = (Element) list.item(i);
57 if(student_tag.getAttribute("examid").equals(examid)){
58 //找到与examid相匹配的学生，new出一个student对象封装这个学生的信息返回
59 Student s = new Student();
60 s.setExamid(examid);
61 s.setIdcard(student_tag.getAttribute("idcard"));
62 s.setName(student_tag.getElementsByTagName("name").item(0).getTextContent());
63 s.setLocation(student_tag.getElementsByTagName("location").item(0).getTextContent());
64 s.setGrade(Double.parseDouble(student_tag.getElementsByTagName("grade").item(0).getTextContent()));
65
66 return s;
67 }
68 }
69
70 return null;
71
72 } catch (Exception e) {
73 throw new RuntimeException(e);
74 }
75
76 }
77
78 public void delete(String name) throws StudentNotExistException{
79
80 try {
81 Document document = XmlUtils.getDocument();
82
83 NodeList list = document.getElementsByTagName("name");
84
85 for (int i = 0; i < list.getLength(); i++) {
86 if(list.item(i).getTextContent().equals(name)){
87 list.item(i).getParentNode().getParentNode().removeChild(list.item(i).getParentNode());
88 //更新内存
89 XmlUtils.write2Xml(document);
90 return;
91 }
92 }
93
94
95
96 throw new StudentNotExistException(name+"not exist");
97 }catch(StudentNotExistException e){
98 throw e;
99 } catch (Exception e) {
100 throw new RuntimeException(e);
101 }
102
103 }
104 }
1 package itacst.utils;
2
3 import java.io.FileOutputStream;
4
5 import javax.xml.parsers.DocumentBuilder;
6 import javax.xml.parsers.DocumentBuilderFactory;
7 import javax.xml.parsers.ParserConfigurationException;
8 import javax.xml.transform.Transformer;
9 import javax.xml.transform.TransformerConfigurationException;
10 import javax.xml.transform.TransformerFactory;
11 import javax.xml.transform.dom.DOMSource;
12 import javax.xml.transform.stream.StreamResult;
13
14 import org.w3c.dom.Document;
15
16 public class XmlUtils {
17
18 private static String filename="src/exam.xml";
19
20 //获取xml
21 public static Document getDocument() throws Exception{
22
23 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
24 DocumentBuilder builder = factory.newDocumentBuilder();
25
26 return builder.parse(filename);
27 }
28
29 //thinking in java
30 public static void write2Xml(Document document) throws Exception{
31
32 TransformerFactory factory = TransformerFactory.newInstance();
33 Transformer tf = factory.newTransformer();
34 tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream(filename)));
35 }
36
37 }
1 package itacst.test;
2
3 import org.junit.Test;
4
5 import itacst.dao.StudentDao;
6 import itacst.domain.Student;
7 import itacst.exception.StudentNotExistException;
8
9 public class StudentDaoTest {
10
11 @Test
12 public void testAdd(){
13 StudentDao dao = new StudentDao();
14 Student s = new Student();
15 s.setExamid("121");
16 s.setName("zero");
17 s.setIdcard("121");
18 s.setLocation("guangzhou");
19 s.setGrade(89);
20 dao.add(s);
21 }
22
23 @Test
24 public void testFind(){
25 StudentDao dao = new StudentDao();
26 Student s = dao.find("121");
27
28 System.out.println(s.getName()+s.getIdcard()+s.getExamid()+s.getLocation()+s.getGrade());
29 }
30
31 @Test
32 public void testDelete() throws Exception{
33 StudentDao dao = new StudentDao();
34 dao.delete("zero");
35 }
36
37 }
1 package itacst.domain;
2
3 public class Student {
4
5 private String idcard;
6 private String examid;
7 private String name;
8 private String location;
9 private double grade;
10
11 public String getIdcard() {
12 return idcard;
13 }
14
15 public void setIdcard(String idcard) {
16 this.idcard = idcard;
17 }
18
19 public String getExamid() {
20 return examid;
21 }
22
23 public void setExamid(String examid) {
24 this.examid = examid;
25 }
26
27 public String getName() {
28 return name;
29 }
30
31 public void setName(String name) {
32 this.name = name;
33 }
34
35 public String getLocation() {
36 return location;
37 }
38
39 public void setLocation(String location) {
40 this.location = location;
41 }
42
43 public double getGrade() {
44 return grade;
45 }
46
47 public void setGrade(double grade) {
48 this.grade = grade;
49 }
50 }
1 package itacst.UI;
2
3 import itacst.dao.StudentDao;
4 import itacst.domain.Student;
5 import itacst.exception.StudentNotExistException;
6
7 import java.io.BufferedReader;
8 import java.io.IOException;
9 import java.io.InputStreamReader;
10
11 public class Main {
12
13 /**
14 * @param args
15 * @throws IOException
16 */
17 public static void main(String[] args) {
18 while(true){
19 try {
20 System.out.println("添加学生(a) 删除学生(b) 查询学生(c)");
21 System.out.println("请输入操作类型：");
22
23 BufferedReader br = new BufferedReader(new InputStreamReader(
24 System.in));
25 String type = br.readLine();
26 if ("a".equals(type)) {
27
28 System.out.print("请输入学生姓名：");
29 String name = br.readLine();
30 System.out.print("请输入学生准考证号：");
31 String examid = br.readLine();
32 System.out.print("请输入学生身份证号：");
33 String idcard = br.readLine();
34 System.out.print("请输入学生所在地：");
35 String location = br.readLine();
36 System.out.print("请输入学生成绩：");
37 String grade = br.readLine();
38
39 Student s = new Student();
40 s.setName(name);
41 s.setExamid(examid);
42 s.setIdcard(idcard);
43 s.setLocation(location);
44 s.setGrade(Double.parseDouble(grade));
45
46 StudentDao dao = new StudentDao();
47 dao.add(s);
48
49 System.out.println("添加成功");
50
51 } else if ("b".equals(type)) {
52
53 System.out.print("请输入要删除的学生姓名：");
54 String name = br.readLine();
55
56 StudentDao dao = new StudentDao();
57 try {
58 dao.delete(name);
59 System.out.println("删除成功！");
60 } catch (StudentNotExistException e) {
61
62 e.printStackTrace();
63 System.out.println("your delete user not exist!!");
64 }
65
66 } else if ("c".equals(type)) {
67
68 } else {
69 System.out.println("unsupport your choice!!");
70 }
71
72 } catch (IOException e) {
73
74 System.out.println("sorry error....");
75 }
76
77 }
78 }
79
80 }
1 <?xml version="1.0" encoding="UTF-8" standalone="no"?><exam> 2 <student examid="222" idcard="111"> 3 <name>zhangsan</name> 4 <location>shenyang</location> 5 <grade>89</grade> 6 </student> 7 <student examid="444" idcard="333"> 8 <name>lisi</name> 9 <location>dalian</location> 10 <grade>97</grade> 11 </student> 12 13 14 <student examid="321" idcard="321"><name>zero</name><location>guangzhou</location><grade>87.9</grade></student></exam>
xml案例(考生成绩管理系统)
时间： 2024-10-20 16:12:19