您可以尝试以下代码：

JSONArray jsonArray = new JSONArray("[{\"a\":1},{\"b\":2,\"c\":3},{\"d\":4},{\"e\":5,\"f\":7}]");
for (int i = 0; i < jsonArray.length(); i++) {
    JSONObject json = jsonArray.getJSONObject(i);
    Iterator<String> keys = json.keys();

    while (keys.hasNext()) {
        String key = keys.next();
        System.out.println("Key :" + key + "  Value :" + json.get(key));
    }

}