java - 从 JSON 字符串 android 中提取数据

Question

我正在尝试从 Github Sample Collection of Books 中提取数据但我得到一个空白屏幕。这是我的 JSON 解析代码。

try {

        JSONObject bookObject = new JSONObject(SAMPLE);
        JSONArray booksArray = bookObject.getJSONArray("books");

        for (int i = 0; i < booksArray.length(); i++){

           JSONObject currentBook = booksArray.getJSONObject(i);

           String title =  currentBook.getString("title");
           String author = currentBook.getString("author");
           String isbn = currentBook.getString("isbn");

           Book book = new Book(title,author,isbn);
           books.add(book);
        }

}catch (JSONException e){
        Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e);
}

Answer 1

我向你推荐使用 GSON，这是一个非常简单的库

到Json

Gson gson = new Gson();

Staff obj = new Staff();

// 1. Java object to JSON file
gson.toJson(obj, new FileWriter("C:\\projects\\staff.json"));

// 2. Java object to JSON string
String jsonInString = gson.toJson(obj);

来自 Json

Gson gson = new Gson();

// 1. JSON file to Java object
Staff staff = gson.fromJson(new FileReader("C:\\projects\\staff.json"), Staff.class);

// 2. JSON string to Java object
String json = "{'name' : 'mkyong'}";
Staff staff = gson.fromJson(json, Staff.class);

// 3. JSON file to JsonElement, later String
JsonElement json = gson.fromJson(new FileReader("C:\\projects\\staff.json"), JsonElement.class);
String result = gson.toJson(json);

如果您想查看更多相关信息，可以查看此链接:https://www.mkyong.com/java/how-do-convert-java-object-to-from-json-format-gson-api/