Java: Extract index src from multiarray

Question

So, I'm encountering this weird problem: I'm using the Woocommerce Rest API and I need to get the src from the "images"-array.

I'v already tried to save the images-array in an other array, but then I have no idea how to get the "src" from the array:

try {
    ConnectionRequest r = new ConnectionRequest();
    r.setPost(false);
    r.setUrl("https://" + tokens.getShop_name_token() + ".ch/wp-json/wc/v3/products?consumer_key=" + tokens.getConsumer_key_token() + "&consumer_secret=" + tokens.getSecret_key_token());
    NetworkManager.getInstance().addToQueueAndWait(r);
    Map<String, Object> result = new JSONParser().parseJSON(new InputStreamReader(new ByteArrayInputStream(r.getResponseData()), "UTF-8"));

    //JSON Filter     
    ArrayList<Map<String, String>> myList = (ArrayList<Map<String, String>>) result.get("root");
    for (int i = 0; i < myList.size(); i++) {
        Map<String, String> dtls = myList.get(i);
        productsArr.add(dtls.get("name"));
        productStock.add(dtls.get("stock_status"));
        productDateCreated.add(dtls.get("date_created"));
        //TODO: Filter out image-soure
        productImages.add(dtls.get("images"));
    }
    System.out.println(productImages);

Output: [[], [], [], [{id=16.0, date_created=2018-11-08T15:21:14, date_created_gmt=2018-11-08T15:21:14, date_modified=2018-11-08T15:21:14, date_modified_gmt=2018-11-08T15:21:14, src=https://website.com/wp-content/uploads/2018/11/1.jpg, name=Vneck Tshirt, alt=}], [{id=15.0, date_created=2018-11-08T15:21:14, date_created_gmt=2018-11-08T15:21:14, date_modified=2018-11-08T15:21:14, date_modified_gmt=2018-11-08T15:21:14, src=https://website.com/wp-content/uploads/2018/11/21.jpg, name=Tshirt, alt=}]]

I got this far. Now my question is: How can I filter out the index to get the "src" of the image?

Answer 1

As you use the rather minimally-featured com.codename1.io.JSONParser JSON parser, which parses JSON to a Map<String, Object> and nothing else, then what you want to do is convert the Object that you get selecting a value to the expected type, and repeat from there.

If the top-level JSON object is an array, then a special "root" element is created, which is what you are getting here. That means that the structure of your JSON is parsed as this:

{
    "root": [
        {
            "name": <str>,
            "stock_status": <???>,
            "date_created": <str>,
            "images": 
                {
                    "id": <num>,
                    "date_*": <str>,
                    "src": <str>,
                    "name": <str>,
                    "alt": <str>
                }
            ]
        }
    ]
}

So, to extract an image's src, you have extracted the "root" array and iterated over it. Instead of casting the results to Map<String, String> however, you want to keep them as Map<String, Object>:

for (const Map<String, Object> element : (List<Map<String, Object>>) result.get("root")) {
    // The "element" object has an "images" value that is a list of objects
    for (const Map<String, Object> image : (List<Map<String, Object>>) element.get("images")) {
        // Save the "src" field of each image
        productImages.add((String) image.get("src"));
    }
}