日常练习-xml成绩管练习

package dao;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import utils.XmlUtils;

import domain.Student;
import exception.StudentNotExistException;

public class StudentDao {
public void add(Student  s){
try {
Document document = XmlUtils.getDocument();
//创建封装学生信息的标签
Element student_tag = document.createElement("student");
student_tag.setAttribute("idcard", s.getIdcard());
student_tag.setAttribute("examid", s.getExamid());

//创建用于封装学生姓名所在地和成绩的标签
Element name = document.createElement("name");
Element location = document.createElement("location");
Element grade = document.createElement("grade");

name.setTextContent(s.getName());
location.setTextContent(s.getLocation());
grade.setTextContent(s.getGrade()+"");

student_tag.appendChild(name);
student_tag.appendChild(location);
student_tag.appendChild(grade);

//封装挂到文档上
document.getElementsByTagName("exam").item(0).appendChild(student_tag);

//更新内存
XmlUtils.write2Xml(document);

} catch (Exception e) {
// TODO Auto-generated catch block
throw new RuntimeException(e);//unchecked exception
}
}

public Student find(String examid){

try {
Document document = XmlUtils.getDocument();
NodeList list = document.getElementsByTagName("student");
for(int i=0;i<list.getLength();i++){
Element student_tag = (Element) list.item(i);
if(student_tag.getAttribute("examid").equals(examid)){
//找到了匹配的学生
Student s = new Student();
s.setExamid(examid);
s.setIdcard(student_tag.getAttribute("idcard"));
s.setName(student_tag.getElementsByTagName("name").item(0).getTextContent());
s.setLocation(student_tag.getElementsByTagName("grade").item(0).getTextContent());
s.setGrade(Double.parseDouble(student_tag.getElementsByTagName("grade").item(0).getTextContent()));
return s;
}
}
return null;

} catch (Exception e) {
// TODO Auto-generated catch block
throw new RuntimeException(e);
}
}

public void delete(String name) throws StudentNotExistException{
try {
Document document = XmlUtils.getDocument();
NodeList list = document.getElementsByTagName("name");
for(int i = 0; i<list.getLength();i++){
if(list.item(i).getTextContent().equals(name)){
list.item(i).getParentNode().getParentNode().removeChild(list.item(i).getParentNode());
XmlUtils.write2Xml(document);
return;
}
}

throw new StudentNotExistException(name+"is not exist!");

}catch(StudentNotExistException e){
throw  e;
}

catch (Exception e) {
// TODO Auto-generated catch block
throw new RuntimeException(e);
}
}

}

package domain;

public class Student {
private String idcard;
private String examid;
private String name;
private String location;
private double grade;
public String getIdcard() {
return idcard;
}
public void setIdcard(String idcard) {
this.idcard = idcard;
}
public String getExamid() {
return examid;
}
public void setExamid(String examid) {
this.examid = examid;
}
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;
}

}

package exception;

public class StudentNotExistException extends Exception {

public StudentNotExistException() {
// TODO Auto-generated constructor stub
}

public StudentNotExistException(String message) {
super(message);
// TODO Auto-generated constructor stub
}

public StudentNotExistException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
}

public StudentNotExistException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
}

public StudentNotExistException(String message, Throwable cause,
boolean enableSuppression, boolean writableStackTrace) {
super(message, cause, enableSuppression, writableStackTrace);
// TODO Auto-generated constructor stub
}

}

package test;

import org.junit.Test;

import dao.StudentDao;
import domain.Student;
import exception.StudentNotExistException;

public class StudentDaoTest {

@Test
public void testAdd(){
StudentDao dao = new StudentDao();
Student s = new Student();
s.setExamid("121");
s.setGrade(89);
s.setIdcard("121");
s.setLocation("北京");
s.setName("aa");
dao.add(s);
}

@Test
public void testFind(){
StudentDao dao = new StudentDao();
dao.find("121");
}

@Test
public void testDelelte() throws StudentNotExistException{
StudentDao dao = new StudentDao();
dao.delete("aa");
}
}

package ui;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import dao.StudentDao;
import domain.Student;
import exception.StudentNotExistException;

public class Main {

public static void main(String[] args) {
System.out.println("添加用户(a)  删除用户(b)   查找学生");
System.out.print("请输入操作类型：");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
try {
String type =br.readLine();

if("a".equals(type)){
System.out.println("请输出姓名");
String name = br.readLine();
System.out.println("请输出准考证号");
String examid = br.readLine();
System.out.println("请输出身份证号码");
String idcard = br.readLine();
System.out.println("请输出所在地");
String location = br.readLine();
System.out.println("请输出成绩");
String grade = br.readLine();

Student s = new Student();
s.setName(name);
s.setIdcard(idcard);
s.setExamid(examid);
s.setLocation(location);
s.setGrade(Double.parseDouble(grade));

StudentDao dao = new StudentDao();
dao.add(s);

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

System.out.println("请输入删除学生");
String name = br.readLine();

StudentDao dao = new StudentDao();
try {
dao.delete(name);
System.out.println("删除成功");
} catch (StudentNotExistException e) {
// TODO Auto-generated catch block
System.out.println("删除的用户不存在");
}
}else if("c".equals(type)){

}else{
System.out.println("不支持的操作");
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("输入出错");
}
}

}

package utils;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.xml.sax.SAXException;

import com.sun.xml.internal.bind.unmarshaller.DOMScanner;

public class XmlUtils {

private static String filename = "src/exam.xml";
public static Document getDocument() throws ParserConfigurationException, SAXException, IOException{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();

return builder.parse(filename);

}

public static void write2Xml(Document docum) throws FileNotFoundException, TransformerException{
TransformerFactory factory = TransformerFactory.newInstance();
Transformer tf = factory.newTransformer();
tf.transform(new DOMSource(docum), new StreamResult(new FileOutputStream(filename)));
}
}

<?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>
</exam>