从PHP编码的JSON数据中获取Null，输出到Java - Getting Null from JSON Data encoded in PHP, outputting to Java

Getting Null from JSON Data encoded in PHP, outputting to Java

我在PHP中的JSON输出是这样完成的：

 print json_encode(array('rate' => $topcat, 'hometown' => $hometown, 'talk' => $talk));

我的JSON输出在浏览器中如下所示：

{"rate"："Movies"，"home"："Seattle，WA"，"talk"："Movies"}

在Java/Android中，我这样做：

受保护的void onPostExecute（void v）｛

    try {
        JSONArray jArray = new JSONArray(result);
        JSONObject json_data = null;
        for (int i = 0; i < jArray.length(); i++) {
            json_data = jArray.getJSONObject(i);

            Hometown = json_data.getString("hometown");
            FavCategory = json_data.getString("rate");              
            Talk = json_data.getString("talk");

        }
    } catch (JSONException e1) {
    } catch (ParseException e1) {
        e1.printStackTrace();
    }
    if (Hometown.equals("")) {
        Hometown = "Not Specified";
    }
    tvHometown.setText(Hometown);
    tvRate.setText(FavCategory);
    tvTalk.setText(Talk);
    Log.d("Log: ", Hometown + " " + FavCategory + " " + Talk);
}

}

在那个日志上，我得到了这个：Seattle, WA, null, null

有人知道为什么吗？

EDIT：新Java代码，仍有错误：

String homeTown = "", favCategory = "", favTalk = "";
        try {
            JSONObject jsonData = new JSONObject(result);
            homeTown = jsonData.getString("hometown");
            favCategory = jsonData.getString("rate");
            favTalk = jsonData.getString("talk");

            tvHometown.setText(homeTown);
            tvRate.setText(favCategory);
            tvTalk.setText(favTalk);


} catch (JSONException e1) {
    } catch (ParseException e1) {
        e1.printStackTrace();
    }

我得到了一个例外：

02-05 08:51:48.078: E/log_tag(22958): Error in http connection org.json.JSONException: Value null of type org.json.JSONObject$1 cannot be converted to JSONArray

尽管有PHP词汇表，这个JSON:的顶级元素

{"rate":"Movies","hometown":"Seattle, WA","talk":"Movies"}

是对象（键值映射），不是是数组。{}是一个彻头彻尾的赠品。

更改此

JSONArray jArray = new JSONArray(result);

到此：

JSONObject jsonData = new JSONObject(result);

然后从那里开始：

String hometown = jsonData.getString("hometown");
String favCategory = jsonData.getString("rate");              
String talk = jsonData.getString("talk");

注意，作为一种良好的Java风格，我是如何使用lowerCamelCased变量名的。

您应该有一个方括号来表示它是一个JSONArray。您的结果在JSONObject中。如果您想获得每个JSONArray的数据，您的结果应该更像这个

{"rate": ["samplevalue","samplevalue"],"Movies" : ["samplevalue","samplevalue"],"hometown":["Seattle, WA"],"talk":["Movies"]}