XStream - unmarshalling - Type specified in XML not visible

Question

I have some XML files stored by XStream a while ago, and they include references to RandomAccessSubList, a class which is not visible beyond the package level and has no default constructor so XStream throws this error:

com.thoughtworks.xstream.converters.ConversionException: Cannot construct java.util.RandomAccessSubList as it does not have a no-args constructor : Cannot construct java.util.RandomAccessSubList as it does not have a no-args constructor

---- Debugging information ----
message             : Cannot construct java.util.RandomAccessSubList as it does not have a no-args constructor
cause-exception     : com.thoughtworks.xstream.converters.reflection.ObjectAccessException
cause-message       : Cannot construct java.util.RandomAccessSubList as it does not have a no-args constructor*

and this is the XML:

<customTimes class="java.util.RandomAccessSubList">
  <l class="list">
    <long>1302174300146</long>
    <long>1302174305231</long>
    <long>1302174310312</long>

etc.

I can't just write a converter for RandomAccessSubList because it's not visible outside the util package. How can I tell XStream to ignore the class for this attribute or how can I specify a converter for a class I can't reference?

Thanks in advance!

score 8 · Accepted Answer · answered Nov 02 '11 at 11:53

I got to the bottom of it - turns out xstream should handle that xml (it doesn't need a no-args constructor), the issue arose because I was using jdk 7 with an older version of xstream (1.3.1). See here http://code.google.com/p/pitestrunner/issues/detail?id=4. Moving back to jdk 6 fixed the issue (for various reasons i can't upgrade).

Before I realised that I did write a converter that worked for RandomAccessSubList if anyone needs it:

public class RandomAccessSubListConverter extends CollectionConverter {

public RandomAccessSubListConverter(Mapper mapper) {
    super(mapper); 
} 

@Override
public boolean canConvert(Class arg0) {     
    return arg0.getName().equals("java.util.RandomAccessSubList");
}

@Override
public Object unmarshal(HierarchicalStreamReader reader,
        UnmarshallingContext context) {        
    reader.moveDown();
    ArrayList arrayList = new ArrayList();
    populateCollection(reader, context, arrayList);
    reader.moveUp();
    return arrayList;
}

Thanks to anyone who was looking into for me!

XStream - unmarshalling - Type specified in XML not visible

1 Answers1