List接口的排序方法sort

代码来源

public class LoginSuccessHandler implements AuthenticationSuccessHandler {
	List<SysMenu> sysMenuList = new ArrayList<>(menuSet);
	sysMenuList.sort(Comparator.comparing(SysMenu::getOrderNum));
}

public interface List<E> extends Collection<E> {
	default void sort(Comparator<? super E> c) {
	    Object[] a = this.toArray();
	    Arrays.sort(a, (Comparator) c);
	    ListIterator<E> i = this.listIterator();
	    for (Object e : a) {
	        i.next();
	        i.set((E) e);
	    }
	}
}

@FunctionalInterface
public interface Comparator<T> {
    public static <T, U extends Comparable<? super U>> Comparator<T> comparing(
            Function<? super T, ? extends U> keyExtractor)
    {
        Objects.requireNonNull(keyExtractor);
        return (Comparator<T> & Serializable)
            (c1, c2) -> keyExtractor.apply(c1).compareTo(keyExtractor.apply(c2));
    }
}