Question

My json string is:

{
    "sigTemplateId": 1,
    "name": "Test Ticket Template",
    "groups": "[{\"sigTemplateId\": 1, \"sigTemplateGroupId\": 1, \"name\": \"Group 1\", \"ordinal\": 1}]"
}

This gets sent from my jsp to the servlet. Servlet code is:

Gson gson = new Gson();

if (jsonData != null) {
    Type objType = new TypeToken<SigTemplateObj>() {}.getType();
    SigTemplateObj sigTemplateToSave = gson.fromJson(jsonData, objType);
    //SigTemplateObj sigTemplateToSave = gson.fromJson(jsonData, SigTemplateObj.class);
}

I get by: java.lang.IllegalStateException: This is not a JSON Array. gson trying to parse the groups array: The JsonDeserializer com.google.gson.DefaultTypeAdapters$CollectionTypeAdapter@1f4db697 failed to deserialize json object “[{\”sigTemplateId\”: 1, \”sigTemplateGroupId\”: 1, \”name\”: \”Group 1\”, \”ordinal\”: 1}]” given the type java.util.ArrayList

My object code is:

public class SigTemplateObj {

    int sigTemplateId;
    String dyninkName;
    int dyninkFormId;
    String name;

    //children collections
    ArrayList<SigTemplateFieldObj> fields;
    ArrayList<SigTemplateGroupObj> groups;
...
}

public class SigTemplateGroupObj {
    int sigTemplateGroupId;
    int sigTemplateId;
    int ordinal;
    String name;
...
}

I have tried both the code above and this line as well and got the same results both times.

SigTemplateObj sigTemplateToSave = gson.fromJson(jsonData, SigTemplateObj.class);

Any help would be appreciated.
Thanks,
Eric

Now I just have to fix my javascript to treat the groups array as an array and not a string:

var testObject = new Object();
        testObject.sigTemplateId = 1;
        testObject.name = 'Test Ticket Template';
        testObject['groups'] = [];
        var testGroup = new Object();
        testGroup.sigTemplateId = 1;
        testGroup.sigTemplateGroupId = 1;
        testGroup.name = 'Group 1';
        testGroup.ordinal = 1;
        testObject.groups.push(testGroup);

        var json = JSON.stringify(testObject);

Answer 1

The groups array is not an array, but a string:

"groups": "..."

Try this JSON instead:

{
    "sigTemplateId": 1,
    "name": "Test Ticket Template",
    "groups": [{"sigTemplateId": 1, "sigTemplateGroupId": 1, "name": "Group 1", "ordinal": 1}]
}