java语言程序设计，设计course类

Question

设计course类，编写方法给课程添加新同学和从一门课程中删除一个同学

Answer 1

import java.util.List;

public class Course {

private String course_id;
private String course_code;
private String course_name;
private List<String> sdtudentIds;

public Course(String course_id, String course_code, String course_name) {
    this.course_id = course_id;
    this.course_code = course_code;
    this.course_name = course_name;
}

public String getCourse_id() {
    return course_id;
}
public void setCourse_id(String course_id) {
    this.course_id = course_id;
}
public String getCourse_code() {
    return course_code;
}
public void setCourse_code(String course_code) {
    this.course_code = course_code;
}
public String getCourse_name() {
    return course_name;
}
public void setCourse_name(String course_name) {
    this.course_name = course_name;
}
public List<String> getSdtudentIds() {
    return sdtudentIds;
}

//添加學生
public boolean addStudent(String studentId) {
    if(studentId != null && !studentId.equals("")) {
        if(!sdtudentIds.contains(studentId)) {
            sdtudentIds.add(studentId);
        }else{
            return false;
        }
    }else {
        return false;
    }
    return true;
}

//移出學生
public void removeStudent(String studentId) {
    if(studentId != null) {
        this.sdtudentIds.remove(studentId);
    }
}

}