Question

我正在构建Android应用，我需要使用localhost中的一些数据填充自定义列表视图。我试图使用volley JsonArrayRequest以JSONObject数组的格式获取数据，但我得到的只是org.json.JSONException: End of input at character 0 of。这是我的json数组请求：

final String URL = "http://10.0.3.2/androidapi/index.php";
        JsonArrayRequest productsReq = new JsonArrayRequest(Method.POST, URL, new Listener<JSONArray>() {

            @Override
            public void onResponse(JSONArray response) {
                Log.d("productTAG", response.toString());
                for(int i = 0; i < response.length(); i++)
                {
                    try 
                    {   
                        JSONObject productObj = response.getJSONObject(i);
                        String title = productObj.getString("title");
                        String description = productObj.getString("description");
                        String category = productObj.getString("category");
                        String subCategory = productObj.getString("subCategory");
                        String size = productObj.getString("size");
                        String price = productObj.getString("price");
                        String thumbnailUrl = productObj.getString("image_one");

                        Product product = new Product(title, thumbnailUrl, description, category, subCategory, size, price);
                        products.add(product);

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

            }
        }, new ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.d("products_error", error.getMessage().toString());
                error.printStackTrace();
            }
        }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> params = new HashMap<String, String>();

                params.put("req", "products");
                params.put("category", category);
                params.put("subCategory", subCategory);

                return params;
            }
        };
        VolleyCore.getInstance(getActivity()).addToRequestQueue(productsReq);

我使用的方法是POST，在getParams下我正在添加名为req的标记，其值为products。我正在index.php中检查此标记。这是我查询表格的函数：

public function getItems($category, $subCategory)
    {
        $query = mysql_query("SELECT * FROM items WHERE category = '$category' AND sub_category = '$subCategory'") or die(mysql_error());


        $objects = array();
        if($query)
        {
            while($objects = mysql_fetch_assoc($query))
            {
                $final[] = $objects;
            }
        }
        return $final;

    }

我在index.php中检查请求：

if(isset($_POST['req']) && $_POST['req'] == 'products')
    {
        $category = $_POST['category'];
        $subCategory = $_POST['subCategory'];


        $obj = $func->getItems($category, $subCategory);

        echo json_encode($obj);

    }

$func是类的实例化，我保留所有使用数据库的方法（包括getItems()）。如果我使用volley StringRequest我会收到回复，但是为什么我在使用JsonArrayRequest时没有收到回复？我做错了什么？
编辑
回复示例

06-28 15:05:58.750: D/productTAG(3853): 


[  
   {  
      "_id":"2",
      "user_email":"unemail",
      "title":"fsdfsd",
      "description":"dffdhfg",
      "pri‌ce":"12",
      "quantity":"12",
      "size":"L",
      "category":"Men",
      "sub_category":"Shoes",
      "imag‌e_one":"base 64 code…",
      "image_two":"base 64 code..",
      "image_three":"base 64 code"
   },
   {  
      "_id":"3",
      "user_email":"unemail",
      "title":"fsdfsd",
      "description":"dffdhfg‌",
      "price":"12",
      "quantity":"12",
      "size":"L",
      "category":"Men",
      "sub_category":"Shoes"      ‌,
      "image_one":"base 64 code",
      "image_two":"base 64 code",
      "image_three":"base 64 code "
   }
]

使用StringRequest。

Answer 1

你应该试试这个

@Override
public void onResponse(String response) 
    try {
        JSONArray myArray = new JSONArray(response);

        for(int i = 0; i < myArray.length(); i++)
        {
            JSONObject jObj = myArray.getJSONObject(i);
            String category = jObj.getString("category");
            Log.d("category", category);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

Answer 2

我无法弄清楚如何使用JsonArrayRequest，所以我使用了我的问题中提到的StringRequest并解析了这样的回复：

@Override
            public void onResponse(String response) {
//              Log.d("productTAG", response);
                try {
                    JSONArray myArray = new JSONArray(response);

                    for(int i = 0; i < myArray.length(); i++)
                    {
                        JSONObject jObj = myArray.getJSONObject(i);
                        String category = jObj.getString("category");
                        Log.d("category", category);

                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

这对我有用，也感谢@Peter P的帮助！

我怎么解析json数组？

2 个答案:

你应该试试这个