无法让Jetty扫描带注释的类

import com.google.common.reflect.ClassPath;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class ClassScanner {

    public static void main(String[] args) throws IOException {
        List<Class<?>> classes = scanClasses();
        for (Class<?> clazz : classes) {
            System.out.println(clazz.getName());
        }
    }

    public static List<Class<?>> scanClasses() throws IOException {
        List<Class<?>> classes = new ArrayList<>();
        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
        ClassPath classPath = ClassPath.from(classLoader);
        for (ClassPath.ClassInfo classInfo : classPath.getTopLevelClassesRecursive("com.example")) {
            classes.add(classInfo.load());
        }
        return classes;
    }
}