面向对象入门——学生信息管理系统01

标签：01 name System 面向对象 Student println 信息管理系统 public out

1.设计过程

1.1类的划分

1.2功能的实现

1.3基本语法

2.代码功能展示

2.1StudentManagementSystemTest

2.2main运行结果

1.设计过程

1.1类的划分

类名	属性	方法	说明
Student.java	学生姓名 private String name	public String getName()	获取Student类的name属性
Student.java	学生姓名 private String name	public void setName(String name)	设置Student类的name属性
StudentManagementSystem.java	学生列表 private List<Student> students	public void addStudent(Student student)	增添学生信息
		public List<Student> getStudents	获取学生信息
		public List<Student> searchByName(String name)	通过姓名搜索学生

Student类

package StudentManagementChange;

public class Student {
    private String name;
    //初始化
    public Student(String name) {
        this.name = name;

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }


    @Override
    public String toString() {
        return "Student{" + "name=" + name  + '}';
    }
}

StudentManagementSystem类

package StudentManagementChange;

import java.util.ArrayList;
import java.util.List;

public class StudentManagementSystem {
    private List<Student> students;

    public StudentManagementSystem() {
        students = new ArrayList<>();
    }
    public void addStudent(Student student) {
        students.add(student);
    }
    public List<Student> getStudents() {
        return students;
    }
    //通过姓名查询学生
    public List<Student> searchByName(String name) {
        List<Student> result = new ArrayList<>();
        for (Student student : students) {
            if (student.getName().equals(name)) {
                result.add(student);
            }
        }
        return result;
    }
}

1.2功能的实现

添加学生（提示输入姓名后创建）
显示所有学生（使用良好的格式显示）
查询学生（输入姓名后查询学生）
退出

（1）添加学生

利用scanner读取学生的姓名
新建学生对象
利用addStudent方法将学生添加到学生列表中


private static void addStudents(Scanner scanner, StudentManagementSystem sms) {
        System.out.println("Enter student name:");
        String name = scanner.next();
        Student student = new Student(name);
        sms.addStudent(student);
        System.out.println("Student added successfully!\n");
    }

（2）显示所有学生

利用getStudent方法获取学生信息
利用if-else判断语句，如果列表不为空则使用foreach循环输出学生信息

private static void showAllStudents(StudentManagementSystem sms) {
        List<Student> studentList = sms.getStudents();
        if(studentList.size()==0){
            System.out.println("The System Date is empty!");
        }
        else{
            for(Student studentItem:studentList){
                System.out.println(studentItem.toString());
            }
        }
    }

（3）查询学生

利用Scanner读取要查找的学生姓名
利用searchByName方法查找学生
利用if-else判断语句，如果searchResults列表不为空则遍历搜索结果，并打印每个符合条件学生的信息

private static void searchStudentsByName(Scanner scanner, StudentManagementSystem sms) {
        System.out.println("Enter student name to search:");
        String searchName = scanner.next();
        List<Student> searchResults = sms.searchByName(searchName);
        if(searchResults.isEmpty()){
            System.out.println("No students found!");
        }
        else{
            System.out.println("Search results:");
            for(Student s : searchResults){
                System.out.println(s);
            }
        }
    }

（4）利用方法简化main

package StudentManagementChange;
import java.util.List;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        StudentManagementSystem sms = new StudentManagementSystem();
        boolean running = true;
        while(running){
            //菜单
            System.out.println("菜单");
            System.out.println("Enter 1 to add a student");
            System.out.println("Enter 2 to show all students");
            System.out.println("Enter 3 to search for a student by name");
            System.out.println("Enter 4 to exit");
            //输出选项
            int choice = scanner.nextInt();
            switch(choice){
                //添加学生
                case 1:
                    addStudents(scanner, sms);
                    break;
                 //展示所有学生
                case 2:
                    showAllStudents(sms);
                    break;
                //通过姓名查询学生
                case 3:
                    searchStudentsByName(scanner, sms);
                    break;
                case 4 :
                    running = false;
                    System.out.println("Exit Successfully!");
                    break;
                default:
                    System.out.println("Invalid choice!");
                    break;
            }
        }
    }

    private static void searchStudentsByName(Scanner scanner, StudentManagementSystem sms) {
        System.out.println("Enter student name to search:");
        String searchName = scanner.next();
        List<Student> searchResults = sms.searchByName(searchName);
        if(searchResults.isEmpty()){
            System.out.println("No students found!");
        }
        else{
            System.out.println("Search results:");
            for(Student s : searchResults){
                System.out.println(s);
            }
        }
    }

    private static void showAllStudents(StudentManagementSystem sms) {
        List<Student> studentList = sms.getStudents();
        if(studentList.size()==0){
            System.out.println("The System Date is empty!");
        }
        else{
            for(Student studentItem:studentList){
                System.out.println(studentItem.toString());
            }
        }
    }

    private static void addStudents(Scanner scanner, StudentManagementSystem sms) {
        System.out.println("Enter student name:");
        String name = scanner.next();
        Student student = new Student(name);
        sms.addStudent(student);
        System.out.println("Student added successfully!\n");
    }
}

1.3基本语法

public和private
利用方法初始化

（1）public 和 private 是 Java 中的访问修饰符，它们用于控制类、方法、变量等成员的可见性和可访问性。了解这些修饰符对于编写清晰、安全和易于维护的代码非常重要。

public：用public修饰的方法和对象可以被任何地方访问，通常用于类的公共方法和属性，特别是那些需要被外部类访问的方法。
public class Student{
    @Override
    public String toString() {
        return "Student{" + "name=" + name  + '}';
    }
}
private：表示该成员只能被其所在的类访问。其他类无法直接访问这些成员，除非通过该类提供的公共方法（如 getter 和 setter）。主要用于封装类的内部状态，防止外部类直接修改或查看类的敏感数据。
public class Student{
    private String name;//name属性
}
（2）利用方法初始化

Student类
private String name;
    //初始化
    public Student(String name) {
        this.name = name;

    }
StudentManegementSystem类
private List<Student> students;

    public StudentManagementSystem() {
        students = new ArrayList<>();
    }

2.代码功能展示

2.1StudentManagementSystemTest

package StudentManagementChange;

public class StudentManagementSystemTest {
    public static void main(String[] args) {
        StudentManagementSystem sms = new StudentManagementSystem();
        Student s1 = new Student("John");
        Student s2 = new Student("Mary");
        Student s3 = new Student("Tom");
        sms.addStudent(s1);
        sms.addStudent(s2);
        sms.addStudent(s3);
        System.out.println("All Students:"+sms.getStudents());
        System.out.println("Search for student by name:"+sms.searchByName("Mary"));

    }
}