Java对象数组学生管理系统

Java对象数组练习

Student类

package Student.com;/** * 学生类 * @author Strive */public class Student {private int id;private String name;private double score;public Student() {}public Student(int id, String name, double score) {this.id = id;this.name = name;this.score = score;}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 double getScore() {return score;}public void setScore(double score) {this.score = score;}}

StudentManager

package Student.com;public class StudentManager {private int index = 1;private int count = 0;private Student[] student;//IDpublic int getStudentId() {return index++;}public StudentManager() {student = new Student[100];String[] name = {"张三","李四","王五","张明","比尔盖茨","礼记","二狗"};double[] score = {70,68,58,98,86,74,94};for (int i = 0; i < student.length; i++) {if (student[i] == null) {if (i == 7) {break;}student[i] = new Student(getStudentId(),name[i],score[i]);count++;}}}/** * 查询所有学生 * @return 学生数组 */public Student[] list() {Student[] stu = new Student[count];for (int i = 0,len = student.length; i < len; i++) {if (student[i] != null) {stu[i] = student[i];}}return stu;}/** * 添加学生 * @param stu 学生对象 * @return 是否成功 */public boolean addStudent(Student stu) {boolean flag = false;for (int i = 0,len = student.length; i < len; i++) {if (student[i] == null) {stu.setId(getStudentId());stu.setName(stu.getName());stu.setScore(stu.getScore());student[i] = stu;count++;flag = true;break;}}return flag;}public boolean removeStudent(int id) {int index = 0;boolean flag = false;for (int i = 0,len = student.length -  1; i < len; i++) {if (student[i] == null) {break;}if (student[i].getId() == id) {count--;index = i;flag = true;break;} }for (int i = index; i < student.length - 1; i++) {student[i] = student[i + 1];}student[student.length - 1] = null;return flag;}public boolean updateStudent(Student s) {boolean flag = false;for (int i = 0,len = student.length; i < len; i++) {if (student[i] == null) {break;}if (student[i].getId() == s.getId()) {student[i].setName(s.getName());student[i].setScore(s.getScore());flag = true;break;}}return flag;}}

Test

package Student.com;import java.util.Scanner;/** * 测试类 * @author Strive */public class Test {private Scanner input = new Scanner(System.in);private StudentManager mana = new StudentManager();public static void main(String[] args) {new Test().Menu();}public void Menu() {do {System.out.println("-----------------欢迎使用学生管理系统!-----------------");System.out.println("1.查看学生");System.out.println("2.删除学生");System.out.println("3.更新学生");System.out.println("4.搜索学生");System.out.println("5.添加学生");System.out.println("6.排序");System.out.println("请输入操作符：");String key = input.next();switch (key) {case "1":all();break;case "2":delete();break;case "3":update();break;case "4":search();break;case "5":add();break;case "6":sort();break;default:System.out.println("输出错误！");continue;}break;} while(true);}public void all() {Student[] list = mana.list();System.out.println("id\t姓名\t成绩");if (list.length != 0) {for (Student li : list) {System.out.println(li.getId() + "\t" + li.getName() + "\t" + li.getScore());}} else {System.out.println("没有更多数据!");}next();}public void add() {do {Student stu = new Student();System.out.println("请输入姓名：");String name = input.next();if (existsStudentName(name)) {System.out.println("学生姓名已存在!");continue;}double score = 0;System.out.println("请输入成绩：");try {score =input.nextDouble();}catch(Exception e) {System.out.println("只能输入数字！");continue;}stu.setName(name);stu.setScore(score);System.out.println(mana.addStudent(stu) == true ? "添加学生\""+name+"\"成功！" : "添加学生\""+name+"\"失败！");next();break;} while(true);}public boolean existsStudentName(String name) {Student[] list = mana.list();for (int i = 0,len = list.length; i < len; i++) {if (list[i].getName().equals(name)) {return true;}}return false;}public void update() {System.out.println("请输入学生id:");int id = input.nextInt();System.out.println("请输入学生姓名:");String name = input.next();System.out.println("请输入学生成绩:");double score = input.nextDouble();Student stu = new Student(id,name,score);System.out.println(mana.updateStudent(stu) == true ? "更新成功！" : "更新失败！");next();}public void search() {System.out.println("请输入学生姓名：");String name = input.next();Student[] list = mana.list();for (int i = 0; i < list.length; i++) {if (list[i].getName().equals(name)) {System.out.println(list[i].getId() + "\t" + list[i].getName() + "\t" + list[i].getScore());}}next();}public void delete() {System.out.println("请输入学生id:");int id = input.nextInt();boolean flag = mana.removeStudent(id);System.out.println(flag == true ? "删除成功！" : "删除失败！");next();}public void sort() {Student[] list = mana.list();Student student;for (int i = 0; i < list.length; i++) {for (int j = 0; j < i; j++) {if (list[i].getScore() > list[j].getScore()) {student = list[i];list[i] = list[j];list[j] = student;}}}for (Student li : list) {System.out.println(li.getId() + "\t" + li.getName() + "\t" + li.getScore());}next();}public void next() {do {System.out.println("按e返回:");String name = input.next();if (name.equals("e")) {Menu();} else {continue;}} while(true);}}