Java基础——学生管理系统
- 用内存存储学生信息。(采用集合的方式）
步骤：
A. 定义学生类
B. 学生管理系统的主界面的代码编写
C. 学生管理系统的查看所有学生的代码编写
D. 学生管理系统的添加学生的代码编写
E. 学生管理系统的删除学生的代码编写
F. 学生管理系统的修改学生的代码编写
代码：
学生类：Student.java
public class Student {
private String id;
private String name;
private String age;
private String address;
public Student(){}
public Student(String id, String name, String age, String address) {
this.id = id;
this.name = name;
this.age = age;
this.address = address;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
import java.util.ArrayList;
import java.util.Scanner;
public class StudentManage {
public static void main(String[] args) {
ArrayList<Student> array = new ArrayList<Student>();
while(true) { //停止的另一种方式，设置标志位flag = true while(flag)
System.out.println("-------------------欢迎来到学生管理系统------------------------");
System.out.println("------ 1. 查看所有学生 -----");
System.out.println("------ 2. 添加学生 -----");
System.out.println("------ 3. 删除学生 -----");
System.out.println("------ 4. 修改学生 -----");
System.out.println("------ 5. 退出 -----");
System.out.println("--------------------------------------------------------------");
System.out.print("请输入您的选择：");
Scanner sc = new Scanner(System.in);
String choice = sc.nextLine();
switch (choice) {
case "1":
//查看所有学生
findAllStudent(array);
System.out.println();
break;
case "2":
//添加学生
addStudent(array);
System.out.println();
break;
case "3":
deleteStudent(array);
System.out.println();
break;
case "4":
updateStudent(array);
System.out.println();
break;
case "5":
default:
// System.out.println("------ 5. 退出 -----");
System.out.println(" 感谢您的使用 ");
//flag = false;
System.exit(0);
break;
}
}
}
//查看所有学生
public static void findAllStudent(ArrayList<Student> array){
if(array.size() == 0){
System.out.println("无学生信息，请重新选择");
return;
}
System.out.println();
System.out.println("学号\t\t\t\t姓名\t\t\t\t年龄\t\t\t\t居住地");
System.out.println("-------------------------------------------------------------------------");
for(int x = 0; x < array.size(); x++)
{
Student s = array.get(x);
System.out.println(s.getId()+"\t\t\t\t" + s.getName() + "\t\t\t\t" + s.getAge() + "\t\t\t\t" + s.getAddress());
}
System.out.println("-------------------------------------------------------------------------");
}
//添加学生
public static void addStudent(ArrayList<Student> array)
{
Scanner in = new Scanner(System.in);
String id ="";
while(true) {
System.out.print("输入学号：");
id = in.nextLine();
int x;
boolean flag = false;
for(x = 0; x < array.size(); x++ )
{
Student s = array.get(x);
if(id.equals(s.getId())) {
flag = true;
break;
}
}
if(flag){
System.out.println("学号被占用，请重新输入");
}
else{
break;
}
}
System.out.print("输入姓名：");
String name = in.nextLine();
System.out.print("输入年龄：");
String age = in.nextLine();
System.out.print("输入地址：");
String address = in.nextLine();
//创建学生对象
Student s = new Student(id,name,age,address);
/*
Student s = new Student();
s.setId(id);
s.setName(name);
s.setAge(age);
s.setAddress(address);
*/
array.add(s);
System.out.println("添加学生成功");
}
//删除学生
public static void deleteStudent(ArrayList<Student> array){
//思路：根据学号删除。先遍历学生列表查看学生是否存在
Scanner in = new Scanner(System.in);
System.out.print("输入要删除学生的学号：");
String id = in.nextLine();
int index = -1;
for(int x = 0; x < array.size(); x++){
Student s = array.get(x);
if(id.equals(s.getId())){
index = x;
break;
}
}
if(index == -1){
System.out.print("该学生信息不存在，是否继续当前删除操作（Yes or No):");
String choice = in.nextLine();
if(choice.equalsIgnoreCase("Yes")){
deleteStudent(array);
}else if(choice.equalsIgnoreCase("No"))
{
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
}else
{
array.remove(index);
System.out.println("删除学生成功");
}
}
//修改学生信息
public static void updateStudent(ArrayList<Student> array){
//输入学号查找学生是否存在
Scanner in = new Scanner(System.in);
System.out.print("输入要更新学生的学号：");
String id = in.nextLine();
int index = -1;
for(int x = 0; x < array.size(); x++){
Student s = array.get(x);
if(id.equals(s.getId())){
index = x;
break;
}
}
if(index == -1){
System.out.print("该学生信息不存在，是否继续当前更新操作（Yes or No):");
String choice = in.nextLine();
if(choice.equalsIgnoreCase("Yes")){
updateStudent(array);
}else if(choice.equalsIgnoreCase("No"))
{
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
}else
{
Student s = array.get(index);
boolean flag = true;
System.out.println("-----选择更新学生信息选项------");
System.out.println("-- 1. 姓名 --");
System.out.println("-- 2. 年龄 --");
System.out.println("-- 3. 地址 --");
System.out.println("-- 4. 返回主界面 --");
System.out.println("--------------------------");
while(flag) {
System.out.print("请输入您的选择：");
Scanner sc = new Scanner(System.in);
String choice = sc.nextLine();
switch (choice) {
case "1":
System.out.print("输入修改姓名：");
String name = in.nextLine();
s.setName(name);
System.out.print("继续更新操作（Yes or No):");
String a = in.nextLine();
if(a.equalsIgnoreCase("Yes"))
break;
else if(a.equalsIgnoreCase("No")){
array.set(index,s);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "2":
System.out.print("输入修改年龄：");
String age = in.nextLine();
s.setAge(age);
System.out.print("继续更新操作（Yes or No):");
String b = in.nextLine();
if(b.equalsIgnoreCase("Yes"))
break;
else if(b.equalsIgnoreCase("No")){
array.set(index,s);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "3":
System.out.print("输入修改地址：");
String address = in.nextLine();
s.setAddress(address);
System.out.print("继续更新操作（Yes or No):");
String c = in.nextLine();
if(c.equalsIgnoreCase("Yes"))
break;
else if(c.equalsIgnoreCase("No")){
array.set(index,s);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "4":
array.set(index,s);
System.out.println("修改信息完成。");
return;
default:
System.out.println("输入信息有误。返回主界面");
return;
}
}
}
}
}
无信息，查看信息时：
添加学生：
在查看信息：
删除学生：
修改学生：
退出：
- 文本存储学生信息
学生类：
public class Student {
private String id;
private String name;
private String age;
private String address;
public Student(){}
public Student(String id, String name, String age, String address) {
this.id = id;
this.name = name;
this.age = age;
this.address = address;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
思路：
（1）输出流：将集合中的内容输出到文本文件中
集合写入文本文件：
需求：键盘录入学生信息（学号，姓名，年龄，居住地）存入集合。然后遍历集合把每一个学生信息存入文本文件(每一个学生信息为一行数据，自己定义分割标记）
分析:
A. 定义学生类
B. 创建集合对象
C. 写方法实现键盘录入学生信息，并把学生对象作为元素添加集合
D. 创建输出缓冲流对象
E. 遍历集合，得到每一个学生信息，并把学生信息按照一定的格式写入文本文件。（123456，wang，22，wuhan)
F. 释放资源
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
public class WriteDemo {
public static void main(String[] args) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
Student s1 = new Student("123456","wang","22","wuhan");
Student s2 = new Student("123457","zhang","28","beijing");
Student s3 = new Student("123458","lisi","20","wixi");
array.add(s1);
array.add(s2);
array.add(s3);
BufferedWriter bw = new BufferedWriter(new FileWriter("array.txt"));
for(int x = 0; x < array.size(); x++)
{
Student s = array.get(x);
StringBuilder sb = new StringBuilder();
sb.append(s.getId()).append(",").append(s.getName()).append(",").append(s.getAge()).append(",").append(s.getAddress());
bw.write(sb.toString());
bw.newLine();
bw.flush();
}
bw.close();
}
}
（2）输入流：从文本文件中读取信息到集合中
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class ReaderDemo {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new FileReader("array.txt"));
ArrayList<Student> array = new ArrayList<Student>();
String line;
while((line = br.readLine())!= null){
String[] strArray = line.split(",");
Student s = new Student(strArray[0],strArray[1],strArray[2],strArray[3]);
array.add(s);
}
br.close();
System.out.println("学号\t\t姓名\t年龄\t居住地");
for(int x = 0; x < array.size(); x++)
{
Student s = array.get(x);
System.out.println(s.getId() + "\t\t" + s.getName() + "\t" + s.getAge() + "\t\t" + s.getAddress());
}
}
}
IO版本代码如下所示：
代码：
注意：一定要先在本项目下创建文件Student.txt，要不然会报错找不到文件
import java.io.*;
import java.util.ArrayList;
import java.util.Scanner;
public class StudentManage {
public static void main(String[] args) throws IOException {
String fileName = "Student.txt";
while(true) {
System.out.println("-------------------欢迎来到学生管理系统------------------------");
System.out.println("------ 1. 查看所有学生 -----");
System.out.println("------ 2. 添加学生 -----");
System.out.println("------ 3. 删除学生 -----");
System.out.println("------ 4. 修改学生 -----");
System.out.println("------ 5. 退出 -----");
System.out.println("--------------------------------------------------------------");
System.out.print("请输入您的选择：");
Scanner sc = new Scanner(System.in);
String choice = sc.nextLine();
switch (choice) {
case "1":
//查看所有学生
findAllStudent(fileName);
System.out.println();
break;
case "2":
//添加学生
addStudent(fileName);
System.out.println();
break;
case "3":
deleteStudent(fileName);
System.out.println();
break;
case "4":
updateStudent(fileName);
System.out.println();
break;
case "5":
default:
// System.out.println("------ 5. 退出 -----");
System.out.println(" 感谢您的使用 ");
//flag = false;
System.exit(0);
break;
}
}
}
//IO输入流：读文件
public static void readData(String fileName, ArrayList<Student> array) throws IOException {
//创建输入缓冲流对象
BufferedReader br = new BufferedReader(new FileReader(fileName));
String line;
while((line = br.readLine()) != null){
String[] datas = line.split(",");
Student s = new Student(datas[0],datas[1],datas[2],datas[3]);
array.add(s);
}
br.close();
}
//IO输出流：写文件
public static void writeData(String fileName, ArrayList<Student> array) throws IOException {
//创建输入缓冲流对象
BufferedWriter bw = new BufferedWriter(new FileWriter(fileName));
for(int x = 0; x < array.size(); x++)
{
Student s = array.get(x);
StringBuilder sb = new StringBuilder();
sb.append(s.getId()).append(",").append(s.getName()).append(",").append(s.getAge()).append(",").append(s.getAddress());
bw.write(sb.toString());
bw.newLine();
bw.flush();
}
bw.close();
}
//查看所有学生
public static void findAllStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readData(fileName,array);
if(array.size() == 0){
System.out.println("无学生信息，请重新选择");
return;
}
System.out.println();
System.out.println("学号\t\t\t\t姓名\t\t\t\t年龄\t\t\t\t居住地");
System.out.println("-------------------------------------------------------------------------");
for(int x = 0; x < array.size(); x++)
{
Student s = array.get(x);
System.out.println(s.getId()+"\t\t\t\t" + s.getName() + "\t\t\t\t" + s.getAge() + "\t\t\t\t" + s.getAddress());
}
System.out.println("-------------------------------------------------------------------------");
}
//添加学生
public static void addStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readData(fileName,array);
Scanner in = new Scanner(System.in);
String id ="";
while(true) {
System.out.print("输入学号：");
id = in.nextLine();
int x;
boolean flag = false;
for(x = 0; x < array.size(); x++ )
{
Student s = array.get(x);
if(id.equals(s.getId())) {
flag = true;
break;
}
}
if(flag){
System.out.println("学号被占用，请重新输入");
}
else{
break;
}
}
System.out.print("输入姓名：");
String name = in.nextLine();
System.out.print("输入年龄：");
String age = in.nextLine();
System.out.print("输入地址：");
String address = in.nextLine();
//创建学生对象
Student s = new Student(id,name,age,address);
/*
Student s = new Student();
s.setId(id);
s.setName(name);
s.setAge(age);
s.setAddress(address);
*/
array.add(s);
writeData(fileName, array);
System.out.println("添加学生成功");
}
//删除学生
public static void deleteStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<>();
readData(fileName,array);
//思路：根据学号删除。先遍历学生列表查看学生是否存在
Scanner in = new Scanner(System.in);
System.out.print("输入要删除学生的学号：");
String id = in.nextLine();
int index = -1;
for(int x = 0; x < array.size(); x++){
Student s = array.get(x);
if(id.equals(s.getId())){
index = x;
break;
}
}
if(index == -1){
System.out.print("该学生信息不存在，是否继续当前删除操作（Yes or No):");
String choice = in.nextLine();
if(choice.equalsIgnoreCase("Yes")){
deleteStudent(fileName);
}else if(choice.equalsIgnoreCase("No"))
{
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
}else
{
array.remove(index);
writeData(fileName,array);
System.out.println("删除学生成功");
}
}
//修改学生信息
public static void updateStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readData(fileName,array);
//输入学号查找学生是否存在
Scanner in = new Scanner(System.in);
System.out.print("输入要更新学生的学号：");
String id = in.nextLine();
int index = -1;
for(int x = 0; x < array.size(); x++){
Student s = array.get(x);
if(id.equals(s.getId())){
index = x;
break;
}
}
if(index == -1){
System.out.print("该学生信息不存在，是否继续当前更新操作（Yes or No):");
String choice = in.nextLine();
if(choice.equalsIgnoreCase("Yes")){
updateStudent(fileName);
}else if(choice.equalsIgnoreCase("No"))
{
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
}else
{
Student s = array.get(index);
boolean flag = true;
System.out.println("-----选择更新学生信息选项------");
System.out.println("-- 1. 姓名 --");
System.out.println("-- 2. 年龄 --");
System.out.println("-- 3. 地址 --");
System.out.println("-- 4. 返回主界面 --");
System.out.println("--------------------------");
while(flag) {
System.out.print("请输入您的选择：");
Scanner sc = new Scanner(System.in);
String choice = sc.nextLine();
switch (choice) {
case "1":
System.out.print("输入修改姓名：");
String name = in.nextLine();
s.setName(name);
System.out.print("继续更新操作（Yes or No):");
String a = in.nextLine();
if(a.equalsIgnoreCase("Yes"))
break;
else if(a.equalsIgnoreCase("No")){
array.set(index,s);
writeData(fileName,array);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "2":
System.out.print("输入修改年龄：");
String age = in.nextLine();
s.setAge(age);
System.out.print("继续更新操作（Yes or No):");
String b = in.nextLine();
if(b.equalsIgnoreCase("Yes"))
break;
else if(b.equalsIgnoreCase("No")){
array.set(index,s);
writeData(fileName,array);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "3":
System.out.print("输入修改地址：");
String address = in.nextLine();
s.setAddress(address);
System.out.print("继续更新操作（Yes or No):");
String c = in.nextLine();
if(c.equalsIgnoreCase("Yes"))
break;
else if(c.equalsIgnoreCase("No")){
array.set(index,s);
writeData(fileName,array);
System.out.println("更新操作完成，返回主界面");
return;
}
else{
System.out.println("输入信息有误，返回主界面");
return;
}
case "4":
array.set(index,s);
writeData(fileName,array);
System.out.println("修改信息完成。");
return;
default:
System.out.println("输入信息有误。返回主界面");
return;
}
}
}
}
}
