2D Arrays - Cannot specify an array dimension after an empty dimension

[nmorel]

2D Arrays - Cannot specify an array dimension after an empty dimension

[nmorel]

Does this work on regular Jackson ?
I never tried to support 2D arrays so it's not surprising it does not work :p

As a workaround, can you try to create your own deserializer for this ?
Using the documentation here : https://github.com/nmorel/gwt-jackson/wiki/Custom-serializers-and-deserializers

I did a quick test, it seems to work.
In your configuration, you add this :

type( String[][].class ).deserializer( MyString2DArrayDeserializer.class );

And the deserializer can look like this :

public class MyString2DArrayDeserializer extends JsonDeserializer<String[][]> {

    @Override
    protected String[][] doDeserialize( JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params ) {

        List<List<String>> res = new ArrayList<List<String>>();

        reader.beginArray();
        while ( JsonToken.END_ARRAY != reader.peek() ) {
            List<String> list = new ArrayList<String>();
            reader.beginArray();
            while ( JsonToken.END_ARRAY != reader.peek() ) {
                list.add( reader.nextString() );
            }
            reader.endArray();
            res.add( list );
        }
        reader.endArray();

        if ( res.isEmpty() ) {
            return new String[0][0];
        }

        String[][] trueRes = new String[res.size()][res.get( 0 ).size()];
        int i = 0;
        for ( List<String> list : res ) {
            int j = 0;
            for ( String s : list ) {
                trueRes[i][j++] = s;
            }
            i++;
        }
        return trueRes;
    }
}

[DanielCloudCredo]

Thanks for the very prompt response! I'll give this a try.

I can confirm 2D arrays work in regular Jackson, 1.9.7 and 2.3.2

[DanielCloudCredo]

Hi - I had a problem deserializing nulls into a 2D string array. I'm not sure if the bug is particular to 2D arrays or a general issue, but I can load the same data in Jackson just fine.

java.lang.IllegalStateException: Expected a string but was NULL at line 1 column 154

The line/column reference above is talking about the source JSON data where the first null occurs.

[nmorel]

Instead of reader.nextString(), try StringJsonDeserializer.getInstance().deserialize(reader, ctx, params). It will take care of the null value.

Or wait for the next release that should come soon. (at least the snapshot)

[nmorel]

The 0.4.1-SNAPSHOT snapshot is available. Can you give it a try ?
If it works for you, I'll release the 0.4.1.

[DanielCloudCredo]

Thanks - I should get a chance to try this tonight or tomorrow.

[DanielCloudCredo]

Hi,

I just had the chance to try 0.4.1-SNAPSHOT, and I'm still getting the same error I'm afraid.

GwtApplication: exception: Couldn't deserialize map [newGfxMap] java.lang.IllegalStateException: Expected a string but was NULL at line 1 column 154

Data snippet:

{"name":"New Map","graphicsPackId":"mxxxxxxGfxPack.json","tileIds":[["1","19","19","19","19","19","19","19","19","19","19","19","19","19","19"],["1",null,null,null,null...

[nmorel]

Did you remove the workaround with the custom deserializer ?
And you can try the 0.5.0

[DanielCloudCredo]

Ha - you pre-empted my absent-mindedness! I will remove that and try again :)