它给出这些错误 类型Email必须实现继承的抽象方法Comparable.compareTo(Object) 类型Email.DateComparator必须实现继承的抽象方法Comparator.compare(对象,对象) 类型Email.SubjectComparator必须实现继承的抽象方法Comparator.compare(对象,对象)Email类型必须实现继承的抽象方法Comparable.compareTo(Object)
虽然我有
public class Email implements Comparable, Serializable
{
...
public static class DateComparator implements Comparator
{
public int compare(Email email1, Email email2)
{
return email1.getTimestamp().compareTo(email2.getTimestamp());
}
}
public static class SubjectComparator implements Comparator
{
public int compare(Email email1, Email email2)
{
return email1.getSubject().compareTo(email2.getSubject());
}
}
}
如何解决?