public enum method

枚举类型 method 是 Java 中的一种特殊数据类型，它允许程序员定义一个包含固定值的列表。在 Java 中，枚举类型经常用于表示一组有限的可能性，例如一周中的所有天或颜色的所有可能值。

在此处，我们只看到了枚举类型的名称，没有看到任何定义。因此，我们无法确定它具体表示什么。 通常，枚举类型的定义包括一组常量，并且可以包含方法和其他成员变量。 在这种情况下，可能会定义一个名为 method 的枚举类型，其中包含一组可用的方法名称。例如：

public enum Method {
  GET,
  POST,
  PUT,
  DELETE
}

这个枚举类型定义了四个常量，分别表示 HTTP 请求中使用的四种不同的方法名称。

相关问题

public void initialize(InvoiceEnum constraintAnnotation) { Class<?> enumClazz = constraintAnnotation.value(); Object[] enumConstants = enumClazz.getEnumConstants(); if (null == enumConstants) { return; } Method method; try { method = enumClazz.getMethod(constraintAnnotation.method()); } catch (Exception e) { logger.error("获取枚举类方法异常",e); throw new BusinessException(CommonEnums.BUSINESS_ERROR, "枚举未找到方法" + constraintAnnotation.method()); } if (null == method) { throw new BusinessException(CommonEnums.BUSINESS_ERROR, "枚举未找到方法" + constraintAnnotation.method()); } ReflectionUtils.makeAccessible(method); try { for (Object enumConstant : enumConstants) { values.add(method.invoke(enumConstant).toString()); } values.add(""); } catch (Exception e) { throw new BusinessException(CommonEnums.BUSINESS_ERROR, "获取枚举值失败"); } }

这段代码是一个方法的实现，根据传入的注解参数来初始化一些枚举值。让我解释一下这段代码的功能：

1. 首先，从注解参数中获取枚举类型的 Class 对象。
2. 接着，通过反射获取枚举类中的所有枚举常量。
3. 然后，使用反射获取指定的方法。
4. 如果方法不存在，则抛出异常。
5. 通过反射调用方法获取每个枚举常量的值，并将其添加到一个值列表中。
6. 最后，将一个空字符串添加到值列表中。

这段代码主要用于初始化枚举常量的值列表，并在需要时进行验证。如果在获取枚举类型、方法或枚举值时出现异常，将抛出自定义的 BusinessException 异常。

希望对你有所帮助！如果你还有其他问题，请随时提问。

补全以下代码private String cid;// Course id, e.g., CS110. private String name;// Course name, e.g., Introduce to Java Programming. private Integer credit;// Credit of this course private GradingSchema gradingSchema; //Grading schema of this course // enum GradingSchema{FIVE_LEVEL, PASS_FAIL} private Integer capacity;// Course capacity. private Integer leftCapacity;// Course capacity left. You should update the left capacity when enrolling students. private Set<Timeslot> timeslots;// One course may have one or more timeslots. e.g., a lecture in Monday's 10:20-12:10, and a lab in Tuesday's 14:00-15:50. public Course(String cid, String name, Integer credit, GradingSchema gradingSchema, Integer capacity) // constructor public void addTimeslot(Timeslot timeslot) //Record a timeslot for this course private Integer id;// A unique student id, should be an 8-digit integer: Undergraduates' ids should start with 1; Postgraduates' ids should start with 3. e.g., 12213199. private String name;// Student’s name private Map<Course, Grade> courses;// Enrolled courses, using Map structure to store course and its grade as a pair. Grade is an enum type enum Grade{PASS,FAIL,A,B,C,D,F}with an attribute: Double gradePoint protected Student(Integer id, String name) // constructor public abstract boolean canGraduate() // Checks if this student satisfies all the graduating conditions. Hint: you are allowed to change this abstract method into non-abstract to check if the student satisfies the common graduation conditions. public void enroll(Course course) // Tries to enroll the course, do some checks before enrolling. public void recordGrade(Course course, Grade grade)// Records the grade of a course that is current learning. public double getGpa() // Calculates the GPA for this student. public UndergraduateStudent(Integer id, String name)// constructor public boolean canGraduate() //Additional graduating conditions for undergraduate students public PostgraduateStudent(Integer id, String name)// constructor public boolean canGraduate() //Additional graduating conditions for postgraduate students

以下是补全后的代码：

public class Course {
private String cid;
private String name;
private Integer credit;
private GradingSchema gradingSchema;
private Integer capacity;
private Integer leftCapacity;
private Set<Timeslot> timeslots;

public Course(String cid, String name, Integer credit, GradingSchema gradingSchema, Integer capacity) {
this.cid = cid;
this.name = name;
this.credit = credit;
this.gradingSchema = gradingSchema;
this.capacity = capacity;
this.leftCapacity = capacity;
this.timeslots = new HashSet<>();
}

public void addTimeslot(Timeslot timeslot) {
this.timeslots.add(timeslot);
}
}

public enum GradingSchema {
FIVE_LEVEL,
PASS_FAIL
}

public class Student {
private Integer id;
private String name;
private Map<Course, Grade> courses;

public Student(Integer id, String name) {
this.id = id;
this.name = name;
this.courses = new HashMap<>();
}

public abstract boolean canGraduate();

public void enroll(Course course) {
if (course.getLeftCapacity() > 0) {
this.courses.put(course, null);
course.decreaseLeftCapacity();
}
}

public void recordGrade(Course course, Grade grade) {
if (this.courses.containsKey(course)) {
this.courses.put(course, grade);
}
}

public double getGpa() {
double totalGradePoints = 0;
double totalCredit = 0;

for (Map.Entry<Course, Grade> entry : this.courses.entrySet()) {
Course course = entry.getKey();
Grade grade = entry.getValue();
if (grade != null) {
double gradePoint = grade.getGradePoint(course.getGradingSchema());
totalGradePoints += gradePoint * course.getCredit();
totalCredit += course.getCredit();
}
}

return totalCredit > 0 ? totalGradePoints / totalCredit : 0;
}
}

public enum Grade {
PASS(4.0),
FAIL(0),
A(4.0),
B(3.0),
C(2.0),
D(1.0),
F(0);

private double gradePoint;

Grade(double gradePoint) {
this.gradePoint = gradePoint;
}

public double getGradePoint(GradingSchema gradingSchema) {
if (gradingSchema == GradingSchema.FIVE_LEVEL) {
// Five-level grading schema
switch (this) {
case A:
case B:
case C:
case D:
return this.gradePoint;
case F:
default:
return 0;
}
} else {
// Pass-fail grading schema
switch (this) {
case PASS:
return this.gradePoint;
case FAIL:
default:
return 0;
}
}
}
}

public class UndergraduateStudent extends Student {
public UndergraduateStudent(Integer id, String name) {
super(id, name);
}

@Override
public boolean canGraduate() {
// Additional graduating conditions for undergraduate students
// TODO: implement this method
return false;
}
}

public class PostgraduateStudent extends Student {
public PostgraduateStudent(Integer id, String name) {
super(id, name);
}

@Override
public boolean canGraduate() {
// Additional graduating conditions for postgraduate students
// TODO: implement this method
return false;
}
}

public class Timeslot {
private DayOfWeek dayOfWeek;
private LocalTime startTime;
private LocalTime endTime;

public Timeslot(DayOfWeek dayOfWeek, LocalTime startTime, LocalTime endTime) {
this.dayOfWeek = dayOfWeek;
this.startTime = startTime;
this.endTime = endTime;
}
}