学生通讯录管理系统JAVA

Student.java 

package com.briup.login;

public class Student {
    private int id;
    private String name;
    private int age;
    private double source;

    public Student() {
        super();
    }

    public Student(int id, String name, int age, double source) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.source = source;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getSource() {
        return source;
    }

    public void setSource(double source) {
        this.source = source;
    }

    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + ", age=" + age + ", source=" + source + "]";
    }

}

Customer.java

package com.briup.login;

public class Customer {
    private String username;
    private String password;

    public Customer() {
        super();
    }

    public Customer(String username, String password) {
        super();
        this.username = username;
        this.password = password;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "Customer [username=" + username + ", password=" + password + "]";
    }

}

Login.java

package com.briup.login;
 
import java.util.HashSet;
import java.util.Scanner;
import com.briup.login2.Customer;
 
public class Login {
	public static HashSet set = new HashSet<>();;
 
	public Login() {
		super();
	}
 
	// 判断登录是否成功
	public static void login(String username, String password) {
		if (set.size() == 0) {
			System.out.println("*登录失败，可能没有注册，请重试！*");
			return;
		}
		for (Customer cust : set) {
			if (cust.getUsername().equals(username)) {
				if (cust.getPassword().equals(password)) {
					System.out.println("*登录成功！*");
					StudentMessages sm = new StudentMessages();
					sm.index();
				} else {
					System.out.println("*登录失败！密码错误！*");
					break;
				}
			} else {
				System.out.println("*登录失败，用户名不存在！*");
				break;
			}
		}
	}
 
	// 判断注册是否成功
	public static boolean register(String username, String password) {
		if (set.size() == 0) {
			System.out.println("*注册成功！！*");
		}
		for (Customer cust : set) {
			if (cust.getUsername().equals(username)) {
				System.out.println("*用户名已存在！！*");
				return false;
			} else {
				System.out.println("*注册成功！！*");
				return true;
			}
		}
		return true;
	}
 
	// 注册主界面
	public void loginindex() {
		while (true) {
			System.out.println("******主界面******");
			System.out.println("*     1.登录          *");
			System.out.println("*     2.注册          *");
			System.out.println("*     0.退出          *");
			System.out.println("*请选择：");
			@SuppressWarnings("resource")
			int num = new Scanner(System.in).nextInt();
			while (true) {
				if (num == 1) {
					System.out.println("*请输入用户名:");
					@SuppressWarnings("resource")
					String name = new Scanner(System.in).nextLine();
					System.out.println("*请输入密码:");
					@SuppressWarnings("resource")
					String password = new Scanner(System.in).nextLine();
					login(name, password);
					break;
				} else if (num == 2) {
					System.out.println("*请输入用户名:");
					@SuppressWarnings("resource")
					String name = new Scanner(System.in).nextLine();
					System.out.println("请输入密码:");
					@SuppressWarnings("resource")
					String password = new Scanner(System.in).nextLine();
					if (register(name, password) == false) {
						break;
					}
					Customer cust = new Customer(name, password);
					set.add(cust);
					break;
				} else if (num == 0) {
					System.out.println("***系统已退出***");
					System.exit(0);
					break;
				} else {
					System.out.println("输入的格式不正确，请重试！！");
				}
			}
		}
	}
}

StudentMessages.java

package com.briup.login;
 
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;
import com.briup.login2.Student;
 
public class StudentMessages {
	public static ArrayList list = new ArrayList<>();
 
	public StudentMessages() {
		super();
	}
 
	// 查询所有学生信息
	public void findAll() {
		if (list.size() == 0) {
			System.out.println("*没有任何学生的信息！！*");
			return;
		} else {
			Iterator iter = list.iterator();
			while (iter.hasNext()) {
				System.out.println(iter.next());
			}
		}
	}
 
	// 添加学生，判断学号是否存在
	public boolean add(int id) {
		if (list.size() == 0) {
			return true;
		}
		for (Student stu : list) {
			if (stu.getId() == id) {
				System.out.println("*学号已存在*");
				return false;
			}
		}
		return true;
	}
 
	// 修改学生信息，判断学号是否存在
	public boolean update(int id, String name, int age, double source) {
		if (list.size() == 0) {
			return false;
		}
		for (Student stu : list) {
			if (stu.getId() == id) {
				stu.setName(name);
				stu.setAge(age);
				stu.setSource(source);
				list.set(id - 1, stu);
				return true;
			}
		}
		if (true) {
			System.out.println("系统中没有该学生的信息！！");
		}
		return false;
	}
 
	// 删除指定id学生信息
	public boolean delete(int id) {
		if (list.size() == 0) {
			return false;
		}
		for (Student stu : list) {
			if (stu.getId() == id) {
				list.remove(id - 1);
				System.out.println("删除成功");
				return true;
			}
		}
		System.out.println("此学号的学生不存在！！");
		return true;
	}
 
	// 设计学生通讯录管理系统主界面
	public void index() {
 
		StudentMessages sm = new StudentMessages();
		s: while (true) {
			System.out.println("*********学生信息管理系统*********");
			System.out.println("*        1.查询学生信息                   *");
			System.out.println("*        2.增加学生信息                   *");
			System.out.println("*        3.修改学生信息                   *");
			System.out.println("*        4.删除学生信息                   *");
			System.out.println("*        0.退出管理系统                   *");
			System.out.println("*请输入：");
			Scanner scanner = new Scanner(System.in);
			int num = scanner.nextInt();
			s2: while (true) {
				if (num == 1) {
					sm.findAll();
					break;
				} else if (num == 2) {
					System.out.println("*请输入学生的id：");
					@SuppressWarnings("resource")
					int id = new Scanner(System.in).nextInt();
					if (sm.add(id) == false) {
						break s2;
					}
					System.out.println("*请输入学生的姓名：");
					@SuppressWarnings("resource")
					String name = new Scanner(System.in).nextLine();
					System.out.println("*请输入学生的年龄：");
					@SuppressWarnings("resource")
					int age = new Scanner(System.in).nextInt();
					System.out.println("*请输入学生的成绩：");
					@SuppressWarnings("resource")
					double source = new Scanner(System.in).nextDouble();
					Student stu = new Student(id, name, age, source);
					list.add(stu);
					System.out.println("添加成功！！");
					break;
				} else if (num == 3) {
					System.out.println("*请输入要修改学生的id：");
					@SuppressWarnings("resource")
					int id = new Scanner(System.in).nextInt();
					System.out.println("*请输入学生的姓名：");
					@SuppressWarnings("resource")
					String name = new Scanner(System.in).nextLine();
					System.out.println("*请输入学生的年龄：");
					@SuppressWarnings("resource")
					int age = new Scanner(System.in).nextInt();
					System.out.println("*请输入学生的成绩：");
					@SuppressWarnings("resource")
					double source = new Scanner(System.in).nextDouble();
					if (sm.update(id, name, age, source) == false) {
						break s2;
					}
					System.out.println("修改成功！！");
					break;
				} else if (num == 4) {
					System.out.println("*请输入学生的id：");
					@SuppressWarnings("resource")
					int id = new Scanner(System.in).nextInt();
					if (sm.delete(id) == false) {
						break s2;
					}
					break;
				} else if (num == 0) {
					System.out.println("****系统已退出！****");
					System.exit(0);
					break s;
				} else {
					System.out.println("输入错误，请重新输入！！");
				}
			}
		}
	}
}

LoginTest.java(测试)

package com.briup.login;

public class LoginTest {
    public static void main(String[] args) {
        Login l = new Login();
        l.loginindex();
    }
}

运行结果：

****注意，类名和包名必须相同。

在运行的时候，必须先注册信息，成功后再登录，登录成功之后，才可以进行信息的查询、增加、修改、删除、退出。