XPages: Creating JSON String recursively

Question

Hello i would like to creat a JSON String with value from Note view. I want to get all the main documents in a view, then gets their responses recursively which will then be return as JSON String.

 {identifier: 'name',
 label: 'name',
items: [
    {"name": "Africa", "": "continent", "children": "[
            { "name":"Egypt", "field":"country" },
            { "name":"Kenya", "field":"country", "children":"[
                { "name":"Nairobi", "field":"city" },
                { "name":"Mombasa", "field":"city" } ]"
            ]},
            { "name":"Sudan", "field":"country", "children":"[
                { "name":'Khartoum', "field":"city" }]"
            },
        { "name":'Asia', "field":"continent", "children":"[
            { "name":"China", "field":"country" },
            { "name":"India", "field":"country"},
            { "name":"Russia", "field":"country" },
            { "name":"Mongolia", "field":"country" } ]"
        }

     }
]}

I have tried the below code which only print out the main document and not the responses which are the children:

public String getJson() {
    Database db = null;
    Document temDoc = null;
    JSONObject json = new JSONObject();
    try {       
        View view1 = database.getView("view1");
        Document doc = view1.getFirstDocument();
        ArrayList<HashMap<String,String>> result = new ArrayList<HashMap<String,String>>();
        while (doc != null) {
            String name =doc.getItemValueString("Name");
            String field = doc.getItemValueString("FieldValue");            
            DocumentCollection respDoc  =doc.getResponses();
            if(!(respDoc.getCount() > 0)){
                result.add(splitHash(name,field));      
            }else{
                result.add(getResp(name,field,respDoc));
            }
            temDoc = view1.getNextSibling(doc);
            doc.recycle();
            doc =temDoc;
        }
        json.put("identifier", "name");
        json.put("label", "name");
        json.put("items", result);
     return json.toJSONString();
}

private HashMap<String, String> getResp(String name, String field,DocumentCollection respDoc) throws NotesException {
    HashMap<String, String> child = new  HashMap<String, String>();
    HashMap<String, String> hmValue = new HashMap<String, String>();    
    Document tmpDoc;    
    String field =""; 
    try {
        Document doc = respDoc.getFirstDocument();
        while (doc != null) {
            name =doc.getItemValueString("Name");
            field = doc.getItemValueString("FieldValue");
            DocumentCollection responses = doc.getResponses();
            if(!(responses.getCount() > 0)){
                hmValue.put(name, name);
                hmValue.put(field, field);      
            }else{
                getResp(name,field,responses);
           hmValue.put("children",hmValue.toString());
            }
            tmpDoc = respDoc.getNextDocument(doc);
            doc.recycle();
            doc =tmpDoc;
        }
    child.addAll(hmValue);
    return child;

}
private HashMap<String, String> splitHash(String name, String field) {
    HashMap<String, String> hm = new hm<String, String>();
        hm.put("name", name);
        hm.put("field", field); 
    return hm;
}

Answer 1

Work with JSONObject and JSONArray to create a hierarchical JSON structure from main documents in view and their responses:

public String getJson() throws NotesException {
    ...
    View view1 = ...;
    JSONObject jsonMain = new JSONObject();
    jsonMain.put("identifier", "name");
    jsonMain.put("label", "name");
    Document doc = view1.getFirstDocument();
    JSONArray items = new JSONArray();
    while (doc != null) {
        items.add(getJsonDocAndChildren(doc));
        Document docTemp = view1.getNextSibling(doc);
        doc.recycle();
        doc = docTemp;
    }
    jsonMain.put("items", items);
    return jsonMain.toJSONString();
}

private JSONObject getJsonDocAndChildren(Document doc) throws NotesException {
    JSONObject jsonDoc = new JSONObject();
    jsonDoc.put("name", doc.getItemValueString("Name"));
    jsonDoc.put("field", doc.getItemValueString("FieldValue"));
    DocumentCollection responses = doc.getResponses();
    if (responses.getCount() > 0) {
        Document docResponse = responses.getFirstDocument();
        JSONArray children = new JSONArray();
        while (docResponse != null) {
            children.add(getJsonDocAndChildren(docResponse));
            Document docTemp = responses.getNextDocument(docResponse);
            docResponse.recycle();
            docResponse = docTemp;
        }
        jsonDoc.put("children", children);
    }
    return jsonDoc;
}

Answer 2

See XPages Help Application (http://xhelp.openntf.org), which does something similar to build the left-hand navigation. With the knowledge I have now, though, I would change the to use JSONJavaObject class to minimise developer errors caused by creating strings rather than letting prebuilt classes do the conversion. But what is there works perfectly well.