Android Retrofit 2 Simple XML Converter
<p>I am using Retrofit <strong>2.1.0</strong> and Retrofit SimpleXML Converter <strong>2.1.0</strong>. I added simplexmlconverter to retrofit instance with addConverterFactory method.</p>

<p>XML is below</p>

<pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;rss xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" xmlns:media="http://search.yahoo.com/mrss/" version="2.0"&gt;
   &lt;channel&gt;
      &lt;title&gt;title&lt;/title&gt;
      &lt;description&gt;&lt;/description&gt;
      &lt;language&gt;en-us&lt;/language&gt;
      &lt;item&gt;
         &lt;title&gt;text&lt;/title&gt;
         &lt;link&gt;text&lt;/link&gt;
         &lt;description&gt;text&lt;/description&gt;
         &lt;enclosure url="text" length="2043520" type="image/jpeg" /&gt;
         &lt;guid isPermaLink="false"&gt;text&lt;/guid&gt;
         &lt;pubDate&gt;Fri, 17 Jun 2016 11:43 EDT&lt;/pubDate&gt;
         &lt;source url="text"&gt;text&lt;/source&gt;
      &lt;/item&gt;
      &lt;item&gt;
         &lt;title&gt;text&lt;/title&gt;
         &lt;link&gt;text&lt;/link&gt;
         &lt;description&gt;text&lt;/description&gt;
         &lt;enclosure url="text" length="1735257" type="image/jpeg" /&gt;
         &lt;guid isPermaLink="false"&gt;text&lt;/guid&gt;
         &lt;pubDate&gt;Thu, 16 Jun 2016 10:17 EDT&lt;/pubDate&gt;
         &lt;source url="text"&gt;&lt;/source&gt;
      &lt;/item&gt;
      &lt;item&gt;
         &lt;title&gt;text&lt;/title&gt;
         &lt;link&gt;text&lt;/link&gt;
         &lt;description&gt;text&lt;/description&gt;
         &lt;enclosure url="text" length="3763157" type="image/jpeg" /&gt;
         &lt;guid isPermaLink="false"&gt;text&lt;/guid&gt;
         &lt;pubDate&gt;Wed, 15 Jun 2016 10:02 EDT&lt;/pubDate&gt;
         &lt;source url="text"&gt;text&lt;/source&gt;
      &lt;/item&gt;
   &lt;/channel&gt;
&lt;/rss&gt;
</code></pre>

<p>My retrofit api client relevant code : <strong>RetrofitAPIClient</strong></p>

<pre><code>OkHttpClient client = new OkHttpClient.Builder()
            .addInterceptor(loggingInterceptor)
            .build();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .client(client)
        .addConverterFactory(SimpleXmlConverterFactory.create())
        .build();

apiService = retrofit.create(MyService.class);
</code></pre>

<p><strong>ArticleResponse.java</strong></p>

<pre><code>import org.simpleframework.xml.Element;
import org.simpleframework.xml.ElementList;
import org.simpleframework.xml.Root;

import java.util.List;

@Root(name = "rss")
public class ArticleResponse {

    @Element(name = "channel")
    public Channel channel;

    public class Channel {

        @ElementList
        public List&lt;Article&gt; articles;
    }
}
</code></pre>

<p><strong>Article.java</strong></p>

<pre><code>import org.simpleframework.xml.Attribute;
import org.simpleframework.xml.Element;
import org.simpleframework.xml.Text;

@Element(name = "item")
public class Article {

    @Element(name = "title")
    private String title;

    @Element(name = "link")
    private String link;

    @Element(name = "description")
    private String description;

    @Element(name = "enclosure")
    private Enclosure enclosure;

    @Element(name = "guid")
    private String guid;

    @Element(name = "pubDate")
    private String pubDate;

    @Element(name = "source")
    private Source source;

    public class Enclosure {

        @Attribute(name = "url")
        private String url;

        @Attribute(name = "length")
        private long length;

        @Attribute(name = "type")
        private String type;
    }

    public class Source {

        @Attribute(name = "url")
        private String url;

        @Text
        private String text;
    }
}
</code></pre>

<p>Error is :</p>

<pre><code>06-18 20:31:22.894 W/System.err: java.lang.RuntimeException: org.simpleframework.xml.core.AttributeException: Attribute 'version' does not have a match in class [my-package].webservice.response.ArticleResponse at line 1
06-18 20:31:22.894 W/System.err:     at retrofit2.converter.simplexml.SimpleXmlResponseBodyConverter.convert(SimpleXmlResponseBodyConverter.java:44)
06-18 20:31:22.894 W/System.err:     at retrofit2.converter.simplexml.SimpleXmlResponseBodyConverter.convert(SimpleXmlResponseBodyConverter.java:23)
06-18 20:31:22.894 W/System.err:     at retrofit2.ServiceMethod.toResponse(ServiceMethod.java:116)
06-18 20:31:22.894 W/System.err:     at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:211)
06-18 20:31:22.894 W/System.err:     at retrofit2.OkHttpCall$1.onResponse(OkHttpCall.java:106)
06-18 20:31:22.894 W/System.err:     at okhttp3.RealCall$AsyncCall.execute(RealCall.java:133)
06-18 20:31:22.894 W/System.err:     at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
06-18 20:31:22.894 W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
06-18 20:31:22.894 W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
06-18 20:31:22.894 W/System.err:     at java.lang.Thread.run(Thread.java:818)
06-18 20:31:22.894 W/System.err: Caused by: org.simpleframework.xml.core.AttributeException: Attribute 'version' does not have a match in class [my-package].webservice.response.ArticleResponse at line 1
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite.readAttribute(Composite.java:494)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite.readAttributes(Composite.java:413)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite.access$300(Composite.java:59)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite$Builder.read(Composite.java:1382)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite.read(Composite.java:201)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Composite.read(Composite.java:148)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Traverser.read(Traverser.java:92)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Persister.read(Persister.java:625)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Persister.read(Persister.java:606)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Persister.read(Persister.java:584)
06-18 20:31:22.895 W/System.err:     at org.simpleframework.xml.core.Persister.read(Persister.java:543)
06-18 20:31:22.895 W/System.err:     at retrofit2.converter.simplexml.SimpleXmlResponseBodyConverter.convert(SimpleXmlResponseBodyConverter.java:36)
06-18 20:31:22.895 W/System.err:    ... 9 more
</code></pre>