From eed79d0581d4d72669c9d9ecadb069558b7900a5 Mon Sep 17 00:00:00 2001 From: pc9pizjb6 <122855890@qq.com> Date: Sat, 1 Nov 2025 22:54:41 +0800 Subject: [PATCH] ADD file via upload --- MainApp.java | 196 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 MainApp.java diff --git a/MainApp.java b/MainApp.java new file mode 100644 index 0000000..7370a35 --- /dev/null +++ b/MainApp.java @@ -0,0 +1,196 @@ +package com.studentmanagement; + +import com.studentmanagement.controller.StudentController; +import com.studentmanagement.model.Student; +import com.studentmanagement.view.StudentConsoleView; +import com.studentmanagement.exception.StudentNotFoundException; +import com.studentmanagement.exception.DuplicateStudentException; +import com.studentmanagement.util.InputUtil; + +/** + * 主应用程序类，系统入口点 + * 初始化MVC组件并启动用户界面 + */ +public class MainApp { + private StudentController controller; + private StudentConsoleView view; + + /** + * 构造函数，初始化控制器和视图 + */ + public MainApp() { + this.controller = new StudentController(); + this.view = new StudentConsoleView(); + } + + /** + * 启动应用程序 + */ + public void start() { + view.displayWelcome(); + boolean running = true; + + while (running) { + view.displayMenu(); + int choice = InputUtil.getIntInput("", 0, 9); + view.displaySeparator(); + + switch (choice) { + case 1: + displayAllStudents(); + break; + case 2: + findStudentById(); + break; + case 3: + addNewStudent(); + break; + case 4: + updateStudent(); + break; + case 5: + deleteStudent(); + break; + case 6: + findStudentsByCourse(); + break; + case 7: + findStudentsWithHighGrades(); + break; + case 8: + showCourseAverageGrade(); + break; + case 9: + showAverageAge(); + break; + case 0: + running = false; + view.displayExit(); + break; + } + } + InputUtil.close(); + } + + /** + * 显示所有学生 + */ + private void displayAllStudents() { + view.displayStudentList(controller.getAllStudents()); + } + + /** + * 根据ID查找学生 + */ + private void findStudentById() { + int id = InputUtil.getIntInput("请输入学生ID: "); + try { + Student student = controller.getStudentById(id); + view.displayStudent(student); + } catch (StudentNotFoundException e) { + view.displayErrorMessage(e.getMessage()); + } + } + + /** + * 添加新学生 + */ + private void addNewStudent() { + int id = InputUtil.getIntInput("请输入学生ID: "); + String name = InputUtil.getNonEmptyStringInput("请输入学生姓名: "); + int age = InputUtil.getIntInput("请输入学生年龄: ", 1, 100); + String course = InputUtil.getNonEmptyStringInput("请输入课程名称: "); + double grade = InputUtil.getDoubleInput("请输入成绩: ", 0, 100); + + Student student = new Student(id, name, age, course, grade); + try { + controller.addStudent(student); + view.displaySuccessMessage("学生添加成功！"); + } catch (DuplicateStudentException e) { + view.displayErrorMessage(e.getMessage()); + } + } + + /** + * 更新学生信息 + */ + private void updateStudent() { + int id = InputUtil.getIntInput("请输入要更新的学生ID: "); + try { + Student existingStudent = controller.getStudentById(id); + view.displayStudent(existingStudent); + + String name = InputUtil.getStringInput("请输入新姓名 (留空保持不变): "); + String course = InputUtil.getStringInput("请输入新课程 (留空保持不变): "); + + // 只有在用户输入了新值时才更新 + if (name.isEmpty()) name = existingStudent.getName(); + if (course.isEmpty()) course = existingStudent.getCourse(); + + int age = InputUtil.getIntInput("请输入新年龄 (0保持不变): ", 0, 100); + if (age == 0) age = existingStudent.getAge(); + + double grade = InputUtil.getDoubleInput("请输入新成绩 (-1保持不变): ", -1, 100); + if (grade == -1) grade = existingStudent.getGrade(); + + Student updatedStudent = new Student(id, name, age, course, grade); + controller.updateStudent(updatedStudent); + view.displaySuccessMessage("学生信息更新成功！"); + } catch (StudentNotFoundException e) { + view.displayErrorMessage(e.getMessage()); + } + } + + /** + * 删除学生 + */ + private void deleteStudent() { + int id = InputUtil.getIntInput("请输入要删除的学生ID: "); + try { + controller.deleteStudent(id); + view.displaySuccessMessage("学生删除成功！"); + } catch (StudentNotFoundException e) { + view.displayErrorMessage(e.getMessage()); + } + } + + /** + * 根据课程查找学生 + */ + private void findStudentsByCourse() { + String course = InputUtil.getNonEmptyStringInput("请输入课程名称: "); + view.displayStudentList(controller.getStudentsByCourse(course)); + } + + /** + * 查找成绩优秀的学生 + */ + private void findStudentsWithHighGrades() { + view.displayStudentList(controller.getStudentsByGradeAbove(90)); + } + + /** + * 显示课程平均成绩 + */ + private void showCourseAverageGrade() { + String course = InputUtil.getNonEmptyStringInput("请输入课程名称: "); + double average = controller.calculateAverageGradeByCourse(course); + view.displayStatistics("课程《" + course + "》的平均成绩为: " + String.format("%.2f", average)); + } + + /** + * 显示学生平均年龄 + */ + private void showAverageAge() { + double averageAge = controller.calculateAverageAge(); + view.displayStatistics("所有学生的平均年龄为: " + String.format("%.2f", averageAge)); + } + + /** + * 主方法，应用程序入口 + */ + public static void main(String[] args) { + MainApp app = new MainApp(); + app.start(); + } +} \ No newline at end of file