java - SimpleXML，org.simpleframework.xml.core.PersistenceException

Question

在经历了很多挫折之后，我来到这里寻求帮助。我正在使用 org.simpleframework.xml 来解析 Android 中的 RSS 提要。尝试解析 xml 文件时出现以下错误:

org.simpleframework.xml.core.PersistenceException: Element 'link' is already used with @org.simpleframework.xml.Element(data=false, name=, required=true, type=void) on field 'link'

这是我要解析的 xml 示例:

<?xml version="1.0" encoding="utf-8" ?>
<rss version="2.0" xml:base="http://www.somelink.com/" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
        <title>My Title</title>
        <description>Latest breaking news, sport, weather and opinion, from South Africa, Africa and the world.</description>
        <link>http://www.somelink.com/</link>
        <atom:link rel="self" href="http://www.someotherlink.com" />
    </channel>
</rss>

这些是我在代码中使用的类和注释:

@Root(name = "rss")
@Namespace(reference = "http://www.w3.org/2005/Atom", prefix = "atom")
public class NewsFeed
{
    @Version(revision = 2.0)
    private float version;

    @Attribute
    private String base;

    @Element
    private Channel channel;
}

@Root(name = "channel")
public class Channel
{
    @Element
    private String title;

    @Element
    private String description;

    @Element
    private String link;

    @Element
    @Namespace(reference = "http://www.w3.org/2005/Atom", prefix = "atom")
    private Link rssLink;

    @ElementList(inline = true)
    private List<NewsItem> newsItems;
}

@Root(name = "link")
public class Link
{
    @Attribute
    private String rel;

    @Attribute
    private String href;

    public String getRel()
    {
        return rel;
    }

    public void setRel(String rel)
    {
        this.rel = rel;
    }

    public String getHref()
    {
        return href;
    }

    public void setHref(String href)
    {
        this.href = href;
    }
}

我创建了 Link 类，以便可以使用 atom 命名空间。正如您从错误中看到的那样，该库似乎没有考虑命名空间，这就是它提示链接元素已被使用的原因。我究竟做错了什么？您的帮助将不胜感激。

Answer 1

我也遇到了同样的问题，看来link和 atom:link即使在不同的命名空间中也被视为相同的条目，它们需要合并到一个 List<Link> rssLink 列表。
这是我用于解析 rss 提要的 kotlin 模型代码，它工作正常:

@Root(name = "rss", strict = false)
data class RssFeed(
    @field:Element(name = "channel")
    var channel: RssChannel = RssChannel()
)

@NamespaceList(
    Namespace(prefix = "atom", reference = "http://www.w3.org/2005/Atom")
)
@Root(name = "channel", strict = false)
data class RssChannel(
    @field:Element var title: String = "",
    @field:Element var description: String = "",
    @field:Element var generator: String = "",
    @field:Element var lastBuildDate: String = "",

    @field:ElementList(entry = "link", required = false, inline = true)
    var links: List<RssLink> = ArrayList(),

    @field:ElementList(inline = true)
    var items: List<RssItem> = ArrayList()
)

@Root(name = "item", strict = false)
data class RssItem(
    @field:Element
    var title: String = "",

    @field:Element
    var pubDate: String = "",

    @field:Element
    var link: String = "",

    @field:Element(required = false)
    var description: String = "",

    @field:Element
    var guid: String = ""
)

@Root(name = "link", strict = false)
data class RssLink(
    // for <link>http://www.somelink.com/</link>
    @field:Text(required = false) var text: String = "",

    // for <atom:link rel="self" href="http://www.someotherlink.com" />
    @field:Attribute(required = false) var rel: String = "",
    @field:Attribute(required = false, name = "type") var contentType: String = "",
    @field:Attribute(required = false) var href: String = ""
)

您也可以查看 here