我要解开

<item>
    <a10:author>
        <a10:name>AuthorName</a10:name>
    </a10:author>
</item>

到

data class Item(val author:String)

如果可能，通过阅读 author/name 进入 author 直接输入字段。如果不能以干净/简单的方式实现，我想创建 Author 与…同班 name 字段，如下所示。在下面的代码中， author.name 是空的，但不应该是。为什么是空的？
示例xml

<?xml version="1.0" encoding="utf-8"?>
<rss xmlns:a10="http://www.w3.org/2005/Atom" version="2.0">
    <channel xmlns:os="http://a9.com/-/spec/opensearch/1.1/">
        <title>SomeTitle</title>
        <link>https://google.com</link>
        <description>SomeDescription</description>
        <os:totalResults>49</os:totalResults>
        <item>
            <link>https://google.com</link>
            <a10:author>
                <a10:name>AuthorName</a10:name>
            </a10:author>
            <title>SomeTitle</title>
            <description>SomeDesc</description>
            <pubDate>Fri, 06 Nov 2020 07:59:27 Z</pubDate>
        </item>
    </channel>
</rss>

所有模型类：

@XmlRootElement(name = "rss", namespace = "http://www.w3.org/2005/Atom")
@XmlAccessorType(XmlAccessType.FIELD)
data class Rss(val channel: RssChannel?) {

    constructor() : this(channel = null)
}

@XmlRootElement(name = "channel", namespace = "http://a9.com/-/spec/opensearch/1.1/")
@XmlAccessorType(XmlAccessType.FIELD)
data class RssChannel  (val link: String,
                        val title: String,
                        val description: String,
                        @field:XmlElement(namespace = "http://a9.com/-/spec/opensearch/1.1/")
                        val totalResults: Int,
                        @field:XmlElement(name = "item")
                        val items: List<Item>?) {

    constructor() : this(link = "", title = "", description = "", totalResults = 0, items = null)
}

@XmlAccessorType(XmlAccessType.FIELD)
data class Item( val title: String,
                 val description: String,
                 val link: String,
                 @field:XmlElement(namespace = "http://www.w3.org/2005/Atom")
                 val author: Author,
                 val pubDate: String) {

    constructor() : this(title = "", description = "", link = "", author = Author(), pubDate = "")
}

@XmlAccessorType(XmlAccessType.FIELD)
data class Author(@XmlElement(namespace = "http://www.w3.org/2005/Atom")
                  val name: String) {

    constructor() : this(name = "")
}