- 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;}}}}
}