java - 从 JSONArray 获取字符串到 String[] 或 List 以输入到 ArrayList

Question

我有这个 JSON 代码，并已成功为其他键创建了对象，但“authors”键给我带来了问题。我已将数据检索到单个字符串中，但它包含不需要的字符，因此在我的适配器类中对其进行了格式化，但我觉得这很草率。

这是 JSON 的 fragment

    {  
   "kind":"books#volumes",
   "totalItems":2816,
   "items":[  
      {  
         "kind":"books#volume",
         "id":"6tLAyQLSzG0C",
         "etag":"N70szFickpY",
         "selfLink":"https://www.googleapis.com/books/v1/volumes/6tLAyQLSzG0C",
         "volumeInfo":{  
            "title":"Android for Work",
            "subtitle":"Productivity for Professionals",
            "authors":[  
               "Marziah Karch"
            ],
            "publisher":"Apress",
            "publishedDate":"2010-09-01",

这是我从 JSON 结果中检索数据的方法 -

public static ArrayList<Books> extractBooks(String jsonString) {
        ArrayList<Books> books = new ArrayList<>();
        String title;
        String[] authors;
        String published;
        String description;
        String url;
        Bitmap bitmap;
        JSONObject imageLinks = null;

        try {
            JSONObject baseJsonObject = new JSONObject(jsonString);
            JSONArray jsonArray = baseJsonObject.getJSONArray("items");


            for (int i = 0; i < jsonArray.length(); i ++) {
                JSONObject currentBook = jsonArray.getJSONObject(i);
                JSONObject items = currentBook.getJSONObject("volumeInfo");
                JSONArray authorArray = items.getJSONArray("authors");
                authors = new String[authorArray.length()];
                for (int a = 0; a < jsonArray.length(); a++) {
                    authors[a]= jsonArray.getString("authors");
                    Log.i(LOG_TAG, "String[] authors: " + authors);
                }
//TODO: Fixed? Keep testing.
                if (items.has("imageLinks")) {
                imageLinks = items.getJSONObject("imageLinks");
                    String image = imageLinks.getString("smallThumbnail");
                    bitmap = extractImages(image);
                } else {
                    bitmap = extractImages("http://books.google.com/books/content?id=M_bMehaHiG0C&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api");
                }

                Boolean hasCover = items.has("imageLinks");
                Log.i(LOG_TAG, "has imageLinks - " + hasCover.toString());



                if (items.has("title")){
                    title = items.getString("title");
                } else {
                    title = "No title available";
                }
                //TODO: Fix authors value to "list" or "array" rather than patching with String.replace in BooksAdapter
//                if (author.has("authors")){
//                    author = items.toString("authors");
//                } else {
//                    author = ("No author available");
//                }
                if (items.has("publishedDate")) {
                    published = items.getString("publishedDate");
                } else {
                    published = null;
                }
                if (items.has("description")){
                    description = items.getString("description");
                } else {
                    description = "No description available";
                }
                if (items.has("infoLink")) {
                    url = items.getString("infoLink");
                } else {
                    url = "none";
                }
                //TODO:Add key for ebook:True||False so can add icon over cover for Google Play Books




                Books book = new Books(title, bitmap, published, description, url, authors);
                books.add(book);
            }
        } catch (JSONException e) {
            Log.e(LOG_TAG, "Problem parsing JSON book results", e);
        }

        return books;
    }

如您所见，这项工作正在进行中!我正在尝试创建一个 for 循环来循环遍历“authors”键并将结果保存在 String[] 中。它不起作用，我收到错误“对作者没有值(value)”。我可以看到，一旦我转到该键，我就没有任何引用值(value)，但我不知道如何继续。

Answer 1

authors":[  // your json array
               "Marziah Karch"
            ],

so authors 包含字符串值，因此您应该使用索引 a 检索它们

你需要使用

authors[a] = authorArray.getString(a);
// i recommend to use optString as authorArray.optString(a);