2_studentsystem.zip

package studentsystem; import java.util.ArrayList; import java.util.Scanner; public class Student { private String id; private String name; private int age; private String address; public Student() { } public Student(String id, String name, int age, String address) { this.id = id; this.name = name; this.age = age; this.address = address; } /** * 获取 * @return id */ public String getId() { return id; } /** * 设置 * @param id */ public void setId(String id) { this.id = id; } /** * 获取 * @return name */ public String getName() { return name; } /** * 设置 * @param name */ public void setName(String name) { this.name = name; } /** * 获取 * @return age */ public int getAge() { return age; } /** * 设置 * @param age */ public void setAge(int age) { this.age = age; } /** * 获取 * @return address */ public String getAddress() { return address; } /** * 设置 * @param address */ public void setAddress(String address) { this.address = address; } public String toString() { return "studentsystem.Student{id = " + id + ", name = " + name + ", age = " + age + ", address = " + address + "}"; } //添加学生 public static void addStudent(ArrayList<Student> list){ Student s = new Student(); Scanner sc = new Scanner(System.in); while (true) { System.out.println("请输入学生的id"); String id = sc.next(); boolean flag = contains(list, id); if (flag){ //表示id存在 System.out.println("id已经存在，请重新录入"); }else { //id不存在 s.setId(id); break; } } System.out.println("请输入学生的姓名"); String name = sc.next(); s.setName(name); System.out.println("请输入学生的年龄"); int age = sc.nextInt(); s.setAge(age); System.out.println("请输入学生的家庭地址"); String address = sc.next(); s.setAddress(address); //把学生对象添加到集合中 list.add(s); System.out.println("学生信息添加成功"); } //删除学生 public static void deleteStudent(ArrayList<Student> list){ System.out.println("请输入需要删除学生的id"); Scanner sc = new Scanner(System.in); String id = sc.next(); //查询id在集合的索引 int index = getIndex(list, id); if (index >= 0){ //表示存在，直接删除 list.remove(index); System.out.println("id为"+id+"的学生删除成功"); } else { System.out.println("id不存在，删除失败"); } } //修改学生 public static void updateStudent(ArrayList<Student> list){ System.out.println("请输入要修改的学生的id"); Scanner sc = new Scanner(System.in); String id = sc.next(); int index = getIndex(list, id); if (contains(list,id)){ //获取要修改的学生对象 Student stu = list.get(index); System.out.println("请输入要修改的学生姓名"); String newName = sc.next(); stu.setName(newName); System.out.println("请输入要修改的学生年龄"); int newAge = sc.nextInt(); stu.setAge(newAge); System.out.println("请输入要修改的学生的家庭地址"); String newAddress = sc.next(); stu.setAddress(newAddress); System.out.println("学生信息修改成功"); } else { System.out.println("要修改的id"+id+"不存在，请重新输入"); } } //查询学生 public static void queryStudent(ArrayList<Student> list){ if (list.size() == 0){ System.out.println("当前无学生信息，请添加后重试"); return; } System.out.println("id\t\t\t\tname\tage\taddress"); for (Student i: list){ System.out.println(i.getId()+"\t"+i.getName()+"\t\t"+i.getAge()+"\t"+i.getAddress()); } } //判断id是否存在 public static boolean contains(ArrayList<Student> list,String id){ return getIndex(list, id) >= 0; } //通过id获得索引 public static int getIndex(ArrayList<Student> list,String id){ for (int i = 0; i < list.size(); i++) { //得到每一个学生对象 Student stu = list.get(i); //得到每一个学生对象的id String sid = stu.getId(); if (sid.equals(id)){ //如果id相同，返回对应索引 return i; } } //如果循环结束还没找到，则说明不存在，返回-1 return -1; } }