ADD file via upload

Student.java

@@ -0,0 +1,116 @@
+package com.studentmanagement.model;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 学生实体类
+ * 表示系统中的学生对象，包含基本信息和课程成绩
+ */
+public class Student {
+    private String id;          // 学生ID
+    private String name;        // 学生姓名
+    private int age;            // 学生年龄
+    private String gender;      // 学生性别
+    private Map<String, Double> courseGrades; // 课程成绩映射
+
+    /**
+     * 构造函数
+     * @param id 学生ID
+     * @param name 学生姓名
+     * @param age 学生年龄
+     * @param gender 学生性别
+     */
+    public Student(String id, String name, int age, String gender) {
+        this.id = id;
+        this.name = name;
+        this.age = age;
+        this.gender = gender;
+        this.courseGrades = new HashMap<>();
+    }
+
+    // Getters and Setters
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String 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 String getGender() {
+        return gender;
+    }
+
+    public void setGender(String gender) {
+        this.gender = gender;
+    }
+
+    public Map<String, Double> getCourseGrades() {
+        return courseGrades;
+    }
+
+    public void setCourseGrades(Map<String, Double> courseGrades) {
+        this.courseGrades = courseGrades;
+    }
+
+    /**
+     * 添加课程成绩
+     * @param course 课程名称
+     * @param grade 成绩
+     */
+    public void addCourseGrade(String course, double grade) {
+        courseGrades.put(course, grade);
+    }
+
+    /**
+     * 获取特定课程的成绩
+     * @param course 课程名称
+     * @return 成绩，如果课程不存在返回null
+     */
+    public Double getCourseGrade(String course) {
+        return courseGrades.get(course);
+    }
+
+    /**
+     * 计算平均成绩
+     * @return 平均成绩，如果没有课程成绩返回0
+     */
+    public double calculateAverageGrade() {
+        if (courseGrades.isEmpty()) {
+            return 0.0;
+        }
+        double sum = 0.0;
+        for (double grade : courseGrades.values()) {
+            sum += grade;
+        }
+        return sum / courseGrades.size();
+    }
+
+    @Override
+    public String toString() {
+        return "Student{" +
+                "id='" + id + "'" +
+                ", name='" + name + "'" +
+                ", age=" + age +
+                ", gender='" + gender + "'" +
+                ", averageGrade=" + String.format("%.2f", calculateAverageGrade()) +
+                "}";
+    }
+}