simpleframework, deserializing an empty element to an empty string instead of null

Answering for completeness

Annotate your element with the convert annotation and give it a converter class as a parameter @Convert(SimpleXMLStringConverter.class)

Create the converter class that does string conversion from null to empty string

public class SimpleXMLStringConverter implements Converter<String> {


    @Override
    public String read(InputNode node) throws Exception {
        String value = node.getValue();
        if(value == null) {
            value = "";
        }
        return value;
    } 

    @Override
    public void write(OutputNode node, String value) throws Exception {
        node.setValue(value);
    }

}

And don't for get to add new AnnotationStrategy() to your persister.