用xml代替数据库的一个小项目--学生管理系统

Student.java

package com.bean;

public class Student {

private String examid;

private String idcard;

private String name;

private String location;

private double grade;

public String getExamid() {

return examid;

}

public void setExamid(String examid) {

this.examid = examid;

}

public String getIdcard() {

return idcard;

}

public void setIdcard(String idcard) {

this.idcard = idcard;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getLocation() {

return location;

}

public void setLocation(String location) {

this.location = location;

}

public double getGrade() {

return grade;

}

public void setGrade(double grade) {

this.grade = grade;

}

}

StudentUtil.java

package com.utils;

import java.io.File;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import com.bean.Student;

public class StudentUtil {

private static final String file = "src/student.xml";

// 获得Document文件的方法

public static Document getDocument() {

try {

DocumentBuilderFactory factory = DocumentBuilderFactory

.newInstance();

DocumentBuilder db = factory.newDocumentBuilder();

return db.parse(file);

} catch (Exception e) {

throw new RuntimeException(e);

}

}

// 写入xml文件的方法

public static void writeXml(Document document) {

try {

Transformer tf = TransformerFactory.newInstance().newTransformer();

tf.transform(new DOMSource(document),new StreamResult(new File(file)));

} catch (Exception e) {

throw new RuntimeException(e);

}

}

//把节点的值封装到bean中

public static Student nodeBean(Element e,Class<Student> c){

try {

Student s = c.newInstance();

s.setExamid(e.getAttribute("examid"));

s.setIdcard(e.getAttribute("idcard"));

s.setName(e.getElementsByTagName("name").item(0).getTextContent());

s.setLocation(e.getElementsByTagName("location").item(0).getTextContent());

s.setGrade(Double.parseDouble(e.getElementsByTagName("grade").item(0).getTextContent()));

return s;

} catch (Exception e1) {

throw new RuntimeException(e1);

}

}

}

StudentDao.java

package com.dao;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NodeList;

import com.bean.Student;

import com.utils.StudentUtil;

public class StudentDao {

/**

* @param args

*/

//增加学生

public void insertS(Student s){

Document document = StudentUtil.getDocument();

//创建sutudet节点

Element rootNode = document.createElement("student");

//给sutudet节点设置属性

rootNode.setAttribute("examid",s.getExamid());

rootNode.setAttribute("idcard",s.getIdcard());

//创建sutudet子节点

Element name = document.createElement("name");

Element location = document.createElement("location");

Element grade = document.createElement("grade");

//给sutudet子节点设值

name.setTextContent(s.getName());

location.setTextContent(s.getLocation());

grade.setTextContent(s.getGrade()+"");

//把sutudet子节点追加到跟节点后

rootNode.appendChild(name);

rootNode.appendChild(location);

rootNode.appendChild(grade);

//把sutudet节点加入到根节点

document.getElementsByTagName("exam").item(0).appendChild(rootNode);

//写入到xml文件

StudentUtil.writeXml(document);

}

//删除学生

public void deleteS(String name){

Document document = StudentUtil.getDocument();

NodeList list = document.getElementsByTagName("name");

for(int i=0;i<list.getLength();i++){

Element node = (Element) list.item(i);

if(node.getTextContent().equals(name)){

node.getParentNode().getParentNode().removeChild(node.getParentNode());

StudentUtil.writeXml(document);

return;

}

}

}

//查询学生

public Student queryS(String examid){

Document document = StudentUtil.getDocument();

NodeList list = document.getElementsByTagName("student");

for(int i=0;i<list.getLength();i++){

Element studentNode = (Element) list.item(i);

String value = studentNode.getAttribute("examid");

if(value.equals(examid)){

Student student = StudentUtil.nodeBean(studentNode, Student.class);

return student;

}

}

return null;

}

}

StudentTest.java

package com.juil;

import org.junit.Test;

import com.bean.Student;

import com.dao.StudentDao;

public class StudentTest {

/**

* @param args

*/

private Student student = new Student();

private StudentDao dao = new StudentDao();

//测试添加学生

@Test

public void insertTest(){

student.setExamid("12345");

student.setIdcard("1122");

student.setName("杨凯");

student.setLocation("邢台");

student.setGrade(100);

dao.insertS(student);

}

@Test

public void queryTest(){

dao.queryS("111");

System.out.println(student.getName());

}

@Test

public void deleteTest(){

dao.deleteS("李小三");

}

}

Main.java

package com.main;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import com.bean.Student;

import com.dao.StudentDao;

public class Main {

public static void main(String[] args) {

while (true) {

try {

System.out.println("添加学生（a） 查找学生（b） 删除学生（c） 退出(quit)");

System.out.print("请选择操作的类型：");

BufferedReader br = new BufferedReader(new InputStreamReader(

System.in));

String type = br.readLine();

if ("quit".equalsIgnoreCase(type)) {

return;

}

if (!type.matches("[abcABC]")) {

System.out.println("请输入正确的操作类型！！");

continue;

}

if (type.equalsIgnoreCase("a")) {

// 进入添加学生环节

try {

System.out.print("请输入学生姓名：");

String name = br.readLine();

System.out.print("请输入学生准考证号：");

String examid = br.readLine();

System.out.print("请输入学生身份证号：");

String idcard = br.readLine();

System.out.print("请输入学生所在地：");

String location = br.readLine();

System.out.print("请输入学生成绩：");

double grade = Double.parseDouble(br.readLine());

Student s = new Student();

s.setExamid(examid);

s.setGrade(grade);

s.setIdcard(idcard);

s.setLocation(location);

s.setName(name);

StudentDao dao = new StudentDao();

dao.insertS(s);

System.out.println("数据录入成功！！");

} catch (Exception e) {

System.out.println("由于未知原因，录入失败！！");

}

} else if (type.equalsIgnoreCase("b")) {

//进入查找环节

try {

System.out.print("请输入学生准考证号：");

String examid = br.readLine();

Student s = new Student();

s.setExamid(examid);

StudentDao dao = new StudentDao();

s = dao.queryS(examid);

System.out.println("名字 :" + s.getName());

System.out.println("准考证号: " + s.getExamid());

System.out.println("学号: " + s.getIdcard());

System.out.println("所在地: " + s.getLocation());

System.out.println("分数: " + s.getGrade());

System.out.println("查找成功!!!");

} catch (RuntimeException e) {

System.out.println("由于未知原因，查询失败！！");

}

} else {

//进入删除环节

try {

System.out.print("请输入学生姓名：");

String name = br.readLine();

Student s = new Student();

s.setName(name);

StudentDao dao = new StudentDao();

dao.deleteS(name);

System.out.println("删除成功!!!");

} catch (RuntimeException e) {

System.out.println("由于未知原因，删除失败！！");

}

}

} catch (Exception e) {

System.out.println("系统出错了，请重新再试！！！");

}

}

}

}

student.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?><exam>

<student examid="222" idcard="111">

<name>张三</name>

<location>沈阳</location>

<grade>89</grade>

</student>

<student examid="444" idcard="333">

<name>李四</name>

<location>大连</location>

<grade>97</grade>

</student>

<student examid="111" idcard="222">

<name>xxx</name>

<location>北京</location>

<grade>45.0</grade>

</student>

<student examid="12345" idcard="1122">

<name>杨凯</name>

<location>邢台</location>

<grade>100.0</grade>

</student>

</exam>