考试系统（未完成的小程序）

  

系统组成：

1、用于封装get和set（name，idcard，grade，examid，location）方法的test_system包

2、用于封装add，delect和find方法的deo包

3、用于封装用户不存在的自定义异常类exception包

4、用于封装测试各类方法的test测试包

5、用于封装和用户打交道的UI界面包

6、用于封装（getdocument方法和把更改操作更新到xml文档中的方法）的utils工具包

7、用于充当数据库的xml文件

 总结：用deo包封装了增、删、查方法，其中在增删查方法里用到了utils包里document方法（获取标签等）以及更新（更改xml文件）方法，另外还会出现一些异常，所以自定义了一个异常包。

      

<?xml version="1.0" encoding="UTF-8" standalone="no"?><exam>//建一个xml文档，充当数据库
    <student examid="4356" idcard="1234">
        <name>aa</name>
        <locationg>沈阳</locationg>
        <grade>89</grade>
    </student>

<student examid="3434" idcard="45656">
    <name>dfdf</name>
    <location>dgerg</location>
    <grade>67.0</grade>
    
</student>
<student examid="7890" idcard="123">
    <name>heeh</name>
    <location>345</location>
    <grade>44.0</grade>
    
    </student>
 
  </exam>

package test_system;
//封装get和set方法
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 getLocation()
    {
        return location;
    }
    public void setLocation(String location)
    {
        this.location=location;
    }
    public String getName()
    {
        return name;
    }
    public void setName(String name)
    {
        this.name=name;
    }
    public double getGrade()
    {
        return grade;
    }
    public void setGrade(  double grade)
    {
        this.grade=grade;
    }
}

package test_system.deo;

//具体封装add方法，delect方法和find方法

import java.rmi.StubNotFoundException;

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

import test_system.student;
import test_system.exception.StudentNotException;
import test_system.utils.xmlutils;

public class studentdeo {

    public void add(student s)
    {
        try {
            Document document= xmlutils.getDocument();
            //创建出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、成绩和所在地的标签
            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);
            //把封装了学生信息的标签挂到文档上
            document.getElementsByTagName("exam").item(0).appendChild(student_tag);
            //更新内存
            xmlutils.writetoxml(document);
            
            
        } catch (Exception e) {
            throw new RuntimeException(e);//此处的异常，不能直接抛给上一级，因为没有意义，又不能打印，因为只能转型成运行异常！
        }
    }
    public student find(String examid)
    {
        try {
            Document document=xmlutils.getDocument();
            NodeList list=document.getElementsByTagName("student");
            for(int i=0;i<list.getLength();i++)
            {
                Element stdent_tag=(Element) list.item(i);
                if(stdent_tag.getAttribute("examid").equals(examid))
                {
                    student s=new student();
                    s.setExamid(examid);
                    s.setIdcard(stdent_tag.getAttribute("idcard"));
                    s.setName(stdent_tag.getElementsByTagName("name").item(0).getTextContent());
                    s.setLocation(stdent_tag.getElementsByTagName("location").item(0).getTextContent());
                    s.setGrade(Double.parseDouble(stdent_tag.getElementsByTagName("grade").item(0).getTextContent()));
                    return s;
                    
                }
                return null;
            }
            
            
        } catch (Exception e) {
            throw new RuntimeException();
        }
        return null;
    }
    public void delect(String name) throws StudentNotException 
    {
        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.writetoxml(document);
                    return;
                }
            }
                    
                throw new StudentNotException(name+"不存在！！！");
                
                
            }catch(StudentNotException e){
                throw e;
            }
            
            
         catch (Exception e) {
            throw new RuntimeException(e);
         }
        
    }
    
 

}

package test_system.UI;
//和用户打交道的界面
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import test_system.student;
import test_system.deo.studentdeo;
import test_system.exception.StudentNotException;

public class main {

    public static void main(String[] args) {
        
        try {
            
            System.out.println("添加学生(a)  删除学生(b)  查找学生(c)");
            System.out.print("请输入操作类型:");
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String type=br.readLine();
            if("a".equals(type))
            {
                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：");
                String grade=br.readLine();
                student s=new student();
                s.setExamid(examid);
                s.setGrade(Double.parseDouble(grade));
                s.setIdcard(idcard);
                s.setLocation(location);
                s.setName(name);
                studentdeo deo=new studentdeo();
                deo.add(s);
                System.out.println("添加成功！！！");
            }
            else if("b".equals(type))
            {
                System.out.println("请输入要删除学生的姓名");
                    String name=br.readLine();
                try {
                    
                    studentdeo deo=new studentdeo();
                    deo.delect(name);
                    System.out.println("删除成功！");
                } catch (StudentNotException e) {
                    System.out.println("你要删除的用户不存在！");
                }
                
                
            }
            else if("c".equals(type))
            {
                System.out.println("请输入要查找学生的考号："); 
                String examid=br.readLine();
                
                
                    studentdeo deo=new studentdeo();
                    student a=deo.find(examid);
                    System.out.print(a.getGrade());//这个地方该如何打印出学生的成绩
                
                
            
            }
            else
            {
                System.out.print("请输入正确的指令");
            }
        } catch (IOException e) {
            
            e.printStackTrace();
            System.out.print("运行出错！！");
        }
    }

}

package test_system.utils;

import java.io.FileOutputStream;

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.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;

public class xmlutils {

    private static String filename="src/exam.xml";
    public static Document getDocument() throws Exception
    {
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        
        return builder.parse(filename);
    }
    //封装把修稿的内容更新到xml文档中的方法
    public static void writetoxml(Document document) throws Exception
    {
        TransformerFactory factory=TransformerFactory.newInstance();
        Transformer tf=factory.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream(filename)));
    
    }
}

package test_system.exception;

//自定义的一个表示学生不存在的异常类
public class StudentNotException extends Exception {

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

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

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

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

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

}

package test_system.test;

import org.junit.Test;

import test_system.student;
import test_system.deo.studentdeo;
import test_system.exception.StudentNotException;

//测试add方法、delect方法和find方法的测试类

public class student_test {

    @Test
    public void studenttest() {
        student a=new student();
        studentdeo deo=new studentdeo();
        a.setExamid("1212");
        a.setGrade(98);
        a.setIdcard("2324355");
        a.setLocation("山东");
        a.setName("山玩意");
        deo.add(a);
        
    }
    @Test
    public void studenttest1() {

        studentdeo deo=new studentdeo();
        deo.find("1212");
    
        
    }
    @Test
    public void studenttest2() throws StudentNotException {

        studentdeo deo=new studentdeo();
        deo.delect("aa");
    
        
    }
    
    
        
    

}