Parsing differently named elements as a single list using SIMPLE XML library for android

Question

I was wondering if there was anyway to treat col_1,col_2...etc as a list rather than separate elements, using the SIMPLE XML Library for Android. I have been reading a bit about substitutions but I'm still confused.

Current Format :

<box-headers 
   dataTable="boxscore" 
   col_1="FINAL" 
   col_2="1" 
   col_3="2" 
   col_4="3" 
   col_5="4" 
   col_6="5" 
   col_7="6" 
   col_8="7" 
   col_9="8" 
   col_10="9" 
   col_11="R" 
   col_12="H" 
   col_13="E">
             table
 </box-headers>

I want to be able to parse out the col's as a list of some sort so I can handle any number of cols. Is this possible?

Answer 1

As ng said before: Use a Converter for this. Simple is brilliant in letting you customize every step of processing (while on the other hand it's possible to let you (de-)serialize even complex structures with some lines of code).

So here's an example:

A Class that will hold the values from the list:

@Root(name = "example")
@Convert(value = ListConverter.class) // Specify the Converter that's used for this class
public class Example
{
    // This element will be set with the values from 'box-headers' element
    @ElementList(name = "box-headers")
    private List<String> values;


    // This constructor is used to set the values while de-serializing
    // You can also use setters instead
    Example(List<String> values)
    {
        this.values = values;
    }

    //...
}

The Converter:

public class ExampleConverter implements Converter<Example>
{
    @Override
    public Example read(InputNode node) throws Exception
    {
        List<String> list = new ArrayList<>(); // List to insert the 'col_' values

        NodeMap<InputNode> attributes = node.getAttributes(); // All attributes of the node
        Iterator<String> itr = attributes.iterator();

        while( itr.hasNext() ) // Iterate over all attributes
        {
            final String name = itr.next(); // The name of the attribute

            if( name.startsWith("col_") ) // Check if it is a 'col' attribute
            {
                // Insert the value of the 'col_' attribute
                list.add(attributes.get(name).getValue());
            }
        }

        // Return the result - instead of a constructor you can use setter(s) too
        return new Example(list); 
    }


    @Override
    public void write(OutputNode node, Example value) throws Exception
    {
        // TODO: Implement serializing here - only required if you want to serialize too
    }
}

How to use:

// Serializer, don't forget `AnnotationStrategy` - without it wont work
Serializer ser = new Persister(new AnnotationStrategy());

// Deserialize the object - here the XML is readen from a file, other sources are possible
Example ex = ser.read(Example.class, new File("test.xml")); 

This example uses only col_xy attributes, everything else is dropped. If you need those values too it's easy to implement them. You only have to retrieve them from the InputNode and set them into your output.