JAVA ZipFile entries()方法没有看到目录

ZipFile zipFile = new ZipFile("example.zip");
Enumeration<? extends ZipEntry> entries = zipFile.entries();
while (entries.hasMoreElements()) {
    ZipEntry entry = entries.nextElement();
    System.out.println(entry.getName());
}

ZipFile zipFile = new ZipFile("example.zip");
Enumeration<? extends ZipEntry> entries = zipFile.entries();
while (entries.hasMoreElements()) {
    ZipEntry entry = entries.nextElement();
    if (entry.isDirectory()) {
        System.out.println("Directory: " + entry.getName());
    } else {
        System.out.println("File: " + entry.getName());
    }
}