Intellij代码格式化，新行上的Java注释(Intellij code formatting, Java annotations on new lines)

 尝试这个： 
 
public interface PopulationMember<T extends PopulationMember> extends Comparable<T> {
    int compareTo(T o);
    T merge(T o);
    // Some other stuff

}
 
 当你填写一个类型参数（就像你为Comparable做的那样），你需要提供一个类。 如果你不希望它是一个特定的类，你可以参数化你的接口。 

Try this:
 
public interface PopulationMember<T extends PopulationMember> extends Comparable<T> {
    int compareTo(T o);
    T merge(T o);
    // Some other stuff

}
 
When you fill in a type parameter (as you do for Comparable), you need to provide a class. If you don't want it to be a specific class, you can parameterize your interface.