java实现选课系统

2023-08-28 19:09:05 318

本文实例为大家分享了java实现选课系统的具体代码，供大家参考，具体内容如下

这个程序主要是练习IO(文件读写，序列化），集合框架的使用

学生端可以实现，查找课程，增加选课，删除选课的功能

管理端可以实现对备选课程，学生信息的增删查改

缺点：登陆操作没有实现密码验证和多态。

另外map对象明明put了，可是get的时候竟然会取到null，而且尝试多次，有时候成功，有时候取到null，并不确定。据说这是由多线程引起的map取值为null，因为多线程部分还没开始学习，所以也没做修改。

//课程信息
packageselectCourse;

importjava.io.Serializable;

publicclassCourseimplementsSerializable{
privateStringid;
privateStringname;

publicCourse(Stringid,Stringname){
super();
this.id=id;
this.name=name;
}

publicCourse(){
super();
}

publicStringgetId(){
returnid;
}

publicvoidsetId(Stringid){
this.id=id;
}

publicStringgetName(){
returnname;
}

publicvoidsetName(Stringname){
this.name=name;
}

publicinthashCode(){
finalintprime=31;
intresult=1;
result=prime*result+((id==null)?0:id.hashCode());
result=prime*result+((name==null)?0:name.hashCode());
returnresult;
}
publicbooleanequals(Objectobj){
if(this==obj)
returntrue;
if(obj==null)
returnfalse;
if(getClass()!=obj.getClass())
returnfalse;
Courseother=(Course)obj;
if(id==null){
if(other.id!=null)
returnfalse;
}elseif(!id.equals(other.id))
returnfalse;
if(name==null){
if(other.name!=null)
returnfalse;
}elseif(!name.equals(other.name))
returnfalse;
returntrue;
}

publicStringtoString(){
return"课程号："+id+""+"课程名："+name;
}

}

//学生信息
packageselectCourse;

importjava.io.Serializable;
importjava.util.HashSet;
importjava.util.Set;

publicclassStudentimplementsSerializable,Comparable{

privateintid;
privateStringname;
privateSetcourses;

publicStudent(intid,Stringname){
super();
this.id=id;
this.name=name;
this.courses=newHashSet();
}

publicStudent(){
super();
this.id=0;
this.name=null;
this.courses=newHashSet();
}

publicintgetId(){
returnid;
}

publicvoidsetId(intid){
this.id=id;
}

publicStringgetName(){
returnname;
}

publicvoidsetName(Stringname){
this.name=name;
}

publicSetgetCourses(){
returncourses;
}

publicvoidsetCourses(Setcourses){
this.courses=courses;
}

publicinthashCode(){
finalintprime=31;
intresult=1;
result=prime*result+id;
returnresult;
}

publicbooleanequals(Objectobj){
if(this==obj)
returntrue;
if(obj==null)
returnfalse;
if(getClass()!=obj.getClass())
returnfalse;
Studentother=(Student)obj;
if(id!=other.id)
returnfalse;
returntrue;
}


publicStringtoString(){
return"学号："+id+""+"姓名："+name;
}
//遍历输出所选课程
publicvoidtravese()
{
if(courses.size()>0)
{
for(Coursecourse:courses){
System.out.println(course);
}
}
else
{
System.out.println("还没有选课");
}
}

publicintcompareTo(Students){

intresult=this.id-s.id;
returnresult;
}


}

//管理端
packageselectCourse;

importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileNotFoundException;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.ObjectInputStream;
importjava.io.ObjectOutputStream;
importjava.util.ArrayList;
importjava.util.Collections;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;
importjava.util.Scanner;

publicclassAdministratorOp{
//管理端，用来管理学生信息和备选课程
Liststudents=newArrayList();
Mapmap1=newHashMap();
Listcourses=newArrayList();
Mapmap2=newHashMap();
Scannerin=newScanner(System.in);

publicAdministratorOp(){
}

//~~~~~~~~~~~~~~~~~从文件读入List~~~~~~~~~~~~~~~~~~~~~
publicvoidload1(){
Filefile=newFile("students.txt");
if(!file.exists()){
try{
file.createNewFile();
}catch(IOExceptione){
e.printStackTrace();
}
}
FileInputStreamfis;
try{
fis=newFileInputStream(file);
ObjectInputStreamois=newObjectInputStream(fis);
students=(List)ois.readObject();
ois.close();
fis.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}catch(ClassNotFoundExceptione){
e.printStackTrace();
}

}

publicvoidload2(){
Filefile=newFile("courses.txt");
if(!file.exists()){
try{
file.createNewFile();
}catch(IOExceptione){
e.printStackTrace();
}
}
FileInputStreamfis;
try{
fis=newFileInputStream(file);
ObjectInputStreamois=newObjectInputStream(fis);
courses=(List)ois.readObject();
ois.close();
fis.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}catch(ClassNotFoundExceptione){
e.printStackTrace();
}

}

//将信息写回文件
publicvoidsave1(){
Filefile=newFile("students.txt");
FileOutputStreamfos;
try{
fos=newFileOutputStream(file);
ObjectOutputStreamoos=newObjectOutputStream(fos);
oos.writeObject(students);
oos.close();
fos.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
//TODO自动生成的catch块
e.printStackTrace();
}

}

publicvoidsave2(){
Filefile=newFile("courses.txt");
FileOutputStreamfos;
try{
fos=newFileOutputStream(file);
ObjectOutputStreamoos=newObjectOutputStream(fos);
oos.writeObject(courses);
oos.close();
fos.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
//TODO自动生成的catch块
e.printStackTrace();
}

}

//~~~~~~~~~~~~~~~~~~~~~~~~~根据List来创建Map~~~~~~~~~~~~~~~~~~~~~~~
publicvoidcreateMap1(){
for(inti=0;i
//学生操作端
packageselectCourse;

importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileNotFoundException;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.ObjectInputStream;
importjava.io.ObjectOutputStream;
importjava.util.ArrayList;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;
importjava.util.Scanner;

publicclassStudentOp{
Scannerin=newScanner(System.in);
Studentst;
Liststudents=newArrayList();
Listcourses=newArrayList();
Mapmap=newHashMap();

publicStudentOp(intno){
load3(no);
load4();

}

//~~~~~~~~~~~~~~~~~从文件读入信息~~~~~~~~~~~~~~~~~~~~~
publicvoidload3(intn){
Filefile=newFile("students.txt");
FileInputStreamfis;
try{
fis=newFileInputStream(file);
ObjectInputStreamois=newObjectInputStream(fis);
students=(List)ois.readObject();
ois.close();
fis.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}catch(ClassNotFoundExceptione){
e.printStackTrace();
}
for(inti=0;i)ois.readObject();
ois.close();
fis.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}catch(ClassNotFoundExceptione){
e.printStackTrace();
}

}

//将信息写回文件
publicvoidsave3(){
Filefile=newFile("students.txt");
FileOutputStreamfos;
try{
fos=newFileOutputStream(file);
ObjectOutputStreamoos=newObjectOutputStream(fos);
oos.writeObject(students);
oos.close();
fos.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
//TODO自动生成的catch块
e.printStackTrace();
}

}

publicvoidsave4(){
Filefile=newFile("courses.txt");
FileOutputStreamfos;
try{
fos=newFileOutputStream(file);
ObjectOutputStreamoos=newObjectOutputStream(fos);
oos.writeObject(courses);
oos.close();
fos.close();
}catch(FileNotFoundExceptione){
e.printStackTrace();
}catch(IOExceptione){
//TODO自动生成的catch块
e.printStackTrace();
}

}

//~~~~~~~~~~~~~~~~~~~~~~~~~根据List来创建Map~~~~~~~~~~~~~~~~~~~~~~~
publicvoidcreateMap(){
for(inti=0;iset=map.keySet();
Iteratoriterator=set.iterator();
while(iterator.hasNext()){
Stringkey=iterator.next();
System.out.println(key+""+map.get(key));
}*/
}

//遍历显示备选课程
publicvoiddisplayAllCourse(){
System.out.println("所有的备选课程信息：");
for(Coursecourse:courses){
System.out.println(course.toString());
}
}

//根据课程号查询备选课程
publicvoidqueryCourse(){
System.out.println("请输入要查询的课程号：");
Stringstr=in.next();
System.out.println(str);
System.out.println((map.containsKey(str)?"yes":"no"));
System.out.println(map.get(str));
}

//显示所选课程
publicvoiddisplay(){
System.out.println("所选课程：");
st.travese();
}

//增加所选课程
publicvoidaddSelect(){
System.out.println("输入所选课程的课程号，输入end结束");
while(true){
Stringid=in.nextLine();
if(!id.equals("end")){
Coursecr=map.get(id);
st.getCourses().add(cr);
System.out.println("选课成功");
}else{
//System.out.println("添加结束");
break;
}
}
}

//减少所选课程
publicvoiddeleteSelect(){
System.out.println("要删除课程的课程号，输入end结束");
while(true){
Stringid=in.nextLine();
if(!id.equals("end")){
Coursecr=map.get(id);
st.getCourses().remove(cr);
System.out.println("删除成功");
}else{
//System.out.println("添加结束");
break;
}
}
}

publicvoidclose(){
in.close();
}
}

//测试类
packageselectCourse;

importjava.util.Scanner;

publicclassTest{

publicstaticvoidmain(String[]args){
//~~~~~~~~~~~~~测试管理端~~~~~~~~~~~~~~~~~~~~~~~~~~
/*添加学生
AdministratorOpa1=newAdministratorOp();
a1.add();
//a1.display1();
//a1.close();
a1.save1();*/
/*添加课程
AdministratorOpa2=newAdministratorOp();
a2.add2();
//a2.display2();
a2.close();
a2.save2();*/
/*//测试删除，查找，修改
AdministratorOpa3=newAdministratorOp();
a3.load1();
a3.createMap1();
a3.load2();
a3.createMap2();
//a3.display1();
//a3.display2();
//a3.del();
//a3.display1();
//a3.del2();
//a3.display2();
//a3.query1();
//a3.query2();
//a3.modify1();
//a3.display1();
//a3.modify2();
//a3.display2();
a3.close();
//a3.save1();
//a3.save2();*/
//~~~~~~~~~~~~~~~~测试学生端~~~~~~~~~~~~~~~~~~~~~~~~~
/*Scannerin=newScanner(System.in);
System.out.println("请输入学号：");
intid=in.nextInt();
StudentOpsto=newStudentOp(id);
sto.createMap();
//sto.displayAllCourse();
//sto.queryCourse();

//sto.addSelect();
//sto.deleteSelect();
sto.display();
sto.close();
in.close();
//sto.save3();
//sto.save4();
*/}

}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。

java实现选课系统

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