xml版本学生管理系统

一： 需求描述

学生成绩管理系统，使用xml存储学生信息，可以对学生信息进行增、删、删除操作。

主要目的：练习操作xml元素的增删改查

二：代码结构

1：xml存储数据如下

exam.xml

 1 xml version="1.0" encoding="UTF-8" standalone="no"?>
 2 <students>
 3     <student>
 4         <name sid="111">李四name>
 5         <age>23age>
 6         <gender>男gender>
 7     student>
 8     <student>
 9         <name sid="222">张三name>
10         <age>21age>
11         <gender>女gender>
12     student>
13 students>

2：Student类封装学生信息

 1 /**
 2  * 
 3  */
 4 package com.hlcui.entity;
 5 
 6 /**
 7  * @author Administrator
 8  * 
 9  */
10 public class Student {
11     private int id;
12     private String name;
13     private int age;
14     private String gender;
15 
16     public int getId() {
17         return id;
18     }
19 
20     public void setId(int id) {
21         this.id = id;
22     }
23 
24     public String getName() {
25         return name;
26     }
27 
28     public void setName(String name) {
29         this.name = name;
30     }
31 
32     public int getAge() {
33         return age;
34     }
35 
36     public void setAge(int age) {
37         this.age = age;
38     }
39 
40     public String getGender() {
41         return gender;
42     }
43 
44     public void setGender(String gender) {
45         this.gender = gender;
46     }
47 
48 }

3:数据访问层，封装操作xml数据的方法

 1 /**
 2  * 
 3  */
 4 package com.hlcui.dao;
 5 
 6 import org.w3c.dom.Document;
 7 import org.w3c.dom.Element;
 8 import org.w3c.dom.NodeList;
 9 
10 import com.hlcui.entity.Student;
11 import com.hlcui.exception.NameNotFoundException;
12 import com.hlcui.utils.StudentUtils;
13 
14 /**
15  * @author Administrator
16  * 
17  */
18 public class StudentDAO {
19     // 添加学生信息
20     public void add(Student stu) {
21         try {
22             Document doc = StudentUtils.getDocument();
23             Element student = doc.createElement("student");
24             student.setAttribute("id", stu.getId() + ""); // 给学生元素添加属性
25 
26             // 分别创建姓名、年龄、性别节点
27             Element name = doc.createElement("name");
28             name.setTextContent(stu.getName());
29             Element age = doc.createElement("age");
30             age.setTextContent(stu.getAge() + "");
31             Element gender = doc.createElement("gender");
32             gender.setTextContent(stu.getGender());
33 
34             // 将姓名、年龄、性别节点添加到学生节点上
35             student.appendChild(name);
36             student.appendChild(age);
37             student.appendChild(gender);
38 
39             // 在将student节点添加到students节点上
40             doc.getElementsByTagName("students").item(0).appendChild(student);
41             StudentUtils.write2XML(doc);
42             System.out.println("添加成功！");
43         } catch (Exception e) {
44             e.printStackTrace();
45         }
46     }
47 
48     // 根据学生姓名查询学生信息
49     public Student find(String name) throws NameNotFoundException {
50         try {
51             Document doc = StudentUtils.getDocument();
52             NodeList list = doc.getElementsByTagName("student");
53             for (int i = 0; i < list.getLength(); i++) {
54                 Element ele = (Element) list.item(i);
55                 if (name.equals((ele.getElementsByTagName("name")).item(0)
56                         .getTextContent())) {
57                     Student stu = new Student();
58                     stu.setId(Integer.parseInt(ele.getAttribute("id")));
59                     stu.setName(name);
60                     stu.setAge(Integer.parseInt((ele
61                             .getElementsByTagName("age")).item(0)
62                             .getTextContent()));
63                     stu.setGender(ele.getElementsByTagName("gender").item(0)
64                             .getTextContent());
65                     return stu;
66                 }
67             }
68             throw new NameNotFoundException(name + "不存在！！！");
69         } catch (NameNotFoundException e) {
70             throw e;
71         } catch (Exception e) {
72             e.printStackTrace();
73         }
74         return null;
75     }
76 
77     // 根据id删除学生信息
78     public boolean delete(int id) {
79         try {
80             Document doc = StudentUtils.getDocument();
81             NodeList list = doc.getElementsByTagName("student");
82             for (int i = 0; i < list.getLength(); i++) {
83                 Element ele = (Element) list.item(i);
84                 if (String.valueOf(id).equals(ele.getAttribute("id"))) {
85                     ele.getParentNode().removeChild(ele);
86                     StudentUtils.write2XML(doc);
87                     return true;
88                 }
89             }
90         } catch (Exception e) {
91             e.printStackTrace();
92         }
93         return false;
94     }
95 }

4：自定义异常类，封装异常

 1 /**
 2  * 
 3  */
 4 package com.hlcui.exception;
 5 
 6 /**
 7  * @author Administrator
 8  *
 9  */
10 public class NameNotFoundException extends Exception {
11 
12     /**
13      * 
14      */
15     private static final long serialVersionUID = 1L;
16 
17     /**
18      * 
19      */
20     public NameNotFoundException() {
21     }
22 
23     /**
24      * @param message
25      */
26     public NameNotFoundException(String message) {
27         super(message);
28     }
29 
30     /**
31      * @param cause
32      */
33     public NameNotFoundException(Throwable cause) {
34         super(cause);
35     }
36 
37     /**
38      * @param message
39      * @param cause
40      */
41     public NameNotFoundException(String message, Throwable cause) {
42         super(message, cause);
43     }
44 
45 }

5：junit框架测试DAO方法

 1 /**
 2  * 
 3  */
 4 package com.hlcui.test;
 5 
 6 import org.junit.Test;
 7 
 8 import com.hlcui.dao.StudentDAO;
 9 import com.hlcui.entity.Student;
10 import com.hlcui.exception.NameNotFoundException;
11 
12 /**
13  * @author Administrator
14  * 
15  */
16 public class TestStudentDAO {
17     private StudentDAO dao = new StudentDAO();
18 
19     @Test
20     public void testAdd() {
21         Student stu = new Student();
22         stu.setId(333);
23         stu.setName("王二");
24         stu.setAge(27);
25         stu.setGender("男");
26         dao.add(stu);
27     }
28 
29     @Test
30     public void testFind() throws NameNotFoundException {
31         String name = "王二";
32         Student stu = dao.find(name);
33         System.out.println("学号：" + stu.getId() + "\n姓名：" + stu.getName()
34                 + "\n年龄：" + stu.getAge() + "\n性别：" + stu.getGender());
35 
36     }
37 
38     @Test
39     public void testDelete() {
40         int id = 333;
41         boolean flag = dao.delete(id);
42         System.out.println(flag ? "删除成功！！" : "删除失败！！");
43     }
44 }

6:封装操作dom文件功能方法

 1 /**
 2  * 
 3  */
 4 package com.hlcui.utils;
 5 
 6 import java.io.FileOutputStream;
 7 import java.io.IOException;
 8 
 9 import javax.xml.parsers.DocumentBuilder;
10 import javax.xml.parsers.DocumentBuilderFactory;
11 import javax.xml.parsers.ParserConfigurationException;
12 import javax.xml.transform.Transformer;
13 import javax.xml.transform.TransformerConfigurationException;
14 import javax.xml.transform.TransformerFactory;
15 import javax.xml.transform.dom.DOMSource;
16 import javax.xml.transform.stream.StreamResult;
17 
18 import org.w3c.dom.Document;
19 
20 /**
21  * @author Administrator
22  * 
23  */
24 public class StudentUtils {
25 
26     /* 获取Document对象* */
27     public static Document getDocument() throws Exception {
28         DocumentBuilderFactory sfb = DocumentBuilderFactory.newInstance();
29         DocumentBuilder db = sfb.newDocumentBuilder();
30         Document doc = db.parse("xml/exam.xml");
31         return doc;
32     }
33 
34     /* 将内存中的内容写到硬盘* */
35     public static void write2XML(Document doc) throws Exception {
36         TransformerFactory factory = TransformerFactory.newInstance();
37         Transformer tf = factory.newTransformer();
38         tf.transform(new DOMSource(doc), new StreamResult(new FileOutputStream(
39                 "xml/exam.xml")));
40     }
41 }

7：用户交互界面

 1 /**
 2  * 
 3  */
 4 package com.hlcui.ui;
 5 
 6 import java.io.BufferedReader;
 7 import java.io.IOException;
 8 import java.io.InputStreamReader;
 9 
10 import com.hlcui.dao.StudentDAO;
11 import com.hlcui.entity.Student;
12 import com.hlcui.exception.NameNotFoundException;
13 
14 /**
15  * @author Administrator 用户交互界面
16  */
17 public class Main {
18 
19     public static StudentDAO dao = new StudentDAO();
20 
21     /**
22      * 
23      * @param args
24      */
25     public static void main(String[] args) {
26 
27         System.out.println("请选择操作模式：a:添加用户    b：查找用户    c：删除用户   exit:退出系统");
28         BufferedReader br = null;
29         try {
30             while (true) {
31                 br = new BufferedReader(new InputStreamReader(System.in));
32                 String type = br.readLine();
33                 if ("a".equals(type)) {
34 
35                     // 录入数据
36                     System.out.println("请输入学号：");
37                     int id = Integer.parseInt(br.readLine());
38                     System.out.println("请输入姓名：");
39                     String name = br.readLine();
40                     System.out.println("请输入年龄：");
41                     int age = Integer.parseInt(br.readLine());
42                     System.out.println("请输入性别：");
43                     String gender = br.readLine();
44                     // 封装数据
45                     Student stu = new Student();
46                     stu.setId(id);
47                     stu.setName(name);
48                     stu.setAge(age);
49                     stu.setGender(gender);
50 
51                     // 插入数据
52                     dao.add(stu);
53                 } else if ("b".equals(type)) {
54                     System.out.println("请输入姓名：");
55                     String name = br.readLine();
56                     try {
57                         Student stu = dao.find(name);
58                         System.out.println("***********学生信息如下***********");
59                         System.out.println("学号：" + stu.getId() + "\n姓名："
60                                 + stu.getName() + "\n年龄：" + stu.getAge()
61                                 + "\n性别：" + stu.getGender());
62                     } catch (NameNotFoundException e) {
63                         System.out.println(e.getMessage());
64                     }
65                 } else if ("c".equals(type)) {
66                     System.out.println("请输入学号：");
67                     int id = Integer.parseInt(br.readLine());
68                     boolean flag = dao.delete(id);
69                     if (flag) {
70                         System.out.println("删除成功！");
71                     } else {
72                         System.out.println("删除失败!");
73                     }
74                 } else if ("exit".equals(type.toLowerCase())) {
75                     System.out.println("系统正在退出...");
76                     try {
77                         Thread.sleep(3000);
78                     } catch (InterruptedException e) {
79                         e.printStackTrace();
80                     }
81                     break;
82                 } else {
83                     System.out.println("您的操作暂不支持，请重新输入:");
84                 }
85             }
86 
87         } catch (IOException e) {
88             e.printStackTrace();
89         } finally {
90             if (null != br) {
91                 try {
92                     br.close();
93                 } catch (IOException e) {
94                     e.printStackTrace();
95                 }
96             }
97         }
98     }
99 }

代码均已经验证正确！