How to solve org.simpleframework.xml.core.ValueRequiredException: Unable to satisfy @org.simpleframework.xml.ElementList()

Santosh Singh picture Santosh Singh · Feb 21, 2017 · Viewed 9.9k times · Source

I'm trying to get books xml data from URL by using Retrofit. But when app runs, it shows error. I am new so please help me. Here is the error msg:

    02-20 23:06:37.943 23835-23835/com.santossingh.reader E/error:
org.simpleframework.xml.core.ValueRequiredException: Unable to satisfy @org.simpleframework.xml.ElementList(data=false, empty=true, entry=, inline=true, name=work, required=true, type=void) on field 'works' public java.util.List com.santossingh.reader.AWS.GoodReadsModels.Results.works for class com.santossingh.reader.AWS.GoodReadsModels.Results at line 2

Here is the XML file structure and my models and classes:

1- The Structure of URL XML file :

<?xml version="1.0" encoding="UTF-8"?>
        <GoodreadsResponse>
          <Request>
            <authentication>true</authentication>
              <key><![CDATA[xxxxx]]></key>
            <method><![CDATA[search_index]]></method>
          </Request>
          <search>
          <query><![CDATA[business]]></query>
            <results-start>1</results-start>
            <results-end>20</results-end>
            <total-results>109755</total-results>
            <source>Goodreads</source>
            <query-time-seconds>0.22</query-time-seconds>
            <results>
                <work>
          <id type="integer">17624817</id>
          <books_count type="integer">85</books_count>
          <ratings_count type="integer">156992</ratings_count>
          <text_reviews_count type="integer">8489</text_reviews_count>
          <original_publication_year type="integer">2011</original_publication_year>
          <original_publication_month type="integer" nil="true"/>
          <original_publication_day type="integer" nil="true"/>
          <average_rating>4.01</average_rating>
          <best_book type="Book">
            <id type="integer">12609433</id>
            <title>The Power of Habit: Why We Do What We Do in Life and Business</title>
            <author>
              <id type="integer">5201530</id>
              <name>Charles Duhigg</name>
            </author>
            <image_url>https://images.gr-assets.com/books/1366758683m/12609433.jpg</image_url>
            <small_image_url>https://images.gr-assets.com/books/1366758683s/12609433.jpg</small_image_url>
          </best_book>
        </work>
      <results>

Here is the clarity of structure <imagelink> of structure XML file for more clarity.

2- Model of Results.class:

@Root (name = "results", strict = false)
public class Results {

    @ElementList (name = "work", inline = true)
    public List<Work> works;

    public Results() {
    }

    public Results(List<Work> works) {
        this.works = works;
    }

    public List<Work> getWorks() {
        return works;
    }

    public void setWorks(List<Work> works) {
        this.works = works;
    }
}

2- Model of Work.class:

@Root(name = "work", strict = false)
public class Work {

    @Path("best_book")
    @Element(name = "id")
    private int id;

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

    @Path("best_book/author")
    @Element(name = "name")
    private String author;

    @Path("best_book")
    @Element (name = "image_url")
    private String image;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }
}

Answer

Santosh Singh picture Santosh Singh · Feb 21, 2017

I found the answer. In the Result.class just change the @ElementList() parameter. Here is the solution:

Error -

    @ElementList(name = "work", inline = true)
    public List<Work> works;

Solution -

    @ElementList(inline = true, required = false)
    public List<Work> works;

Whenever that error occured just remember two things in @ElementList()

1- inline=true
2- required=false
example : @ElementList(inline = true, required = false)