4、班级（ClassGrade）是由学生（Student）组成的。请用类图表示他们之间的关系；并用
1、班级（ClassGrade）是由学生（Student）组成的。请用类图表示他们之间的关系；并用代码进行实现。
```
package 面向对象基本概念综合练习;
import java.util.List;
public class 课堂练习题4 {
public class ClassGrade {
private List<Student> studentList;
public ClassGrade(List<Student> studentList) {
this.studentList = studentList;
}
public List<Student> getStudentList() {
return studentList;
}
}
public class Student {
private String name;
private int age;
private String gender;
private String studentId;
public Student(String name, int age, String gender, String studentId) {
this.name = name;
this.age = age;
this.gender = gender;
this.studentId = studentId;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public String getGender() {
return gender;
}
public String getStudentId() {
return studentId;
}
}
}
+---------------------+ +------------------------+
| ClassGrade | | Student |
+---------------------+ +------------------------+
| -className: string | | -studentName: string |
| -studentList: list | | -studentID: int |
| | | -classGrade: ClassGrade |
| +addStudent(): void | | |
| +removeStudent(): void| | |
| | | |
+---------------------+ +------------------------+
```
代码实现：
```java
// Person类
public class Person {
public void useTool() {
// 使用工具
}
}
// Boat类
public class Boat {
private List personList = new ArrayList<>();
public void addPerson(Person person) {
personList.add(person);
}
public void removePerson(Person person) {
personList.remove(person);
}
}
// Radio类
public class Radio {
public void openRadio() {
// 打开收音机
}
public void consumeElectricity(Battery battery) {
battery.setElectricityAmount(battery.getElectricityAmount() - 10);
}
}
// Battery类
public class Battery {
private int electricityAmount = 100;
public void addBattery() {
electricityAmount = 100;
}
public void setElectricityAmount(int amount) {
electricityAmount = amount;
}
public int getElectricityAmount() {
return electricityAmount;
}
}
// ClassGrade类
public class ClassGrade {
private Counselor counselor;
// 其他属性和方法
public void setCounselor(Counselor counselor) {
this.counselor = counselor;
}
}
// Counselor类
public class Counselor {
public void manageDailyTask(ClassGrade classGrade) {
// 管理班级日常工作
}
}
```
