我想将服务器中的图像放入我的Android应用程序中。我的第一步是:
我有来自server的这个JSON字符串数组
{"results":"[{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara1.jpg\"},{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara2.jpg\"},{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara3.jpg\"}]"}
我从我的应用程序中获取了以下代码并且工作正常的服务器中的URL。
private void getURLs() {
class GetURLs extends AsyncTask<String, Void, String> {
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(GalleryTargets.this, "Loading...", "Please Wait...", true, true);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
Toast.makeText(GalleryTargets.this,s,Toast.LENGTH_LONG).show();
imageJSON = s;
Log.e(LOGTAG, "Succeed Read url" + imageJSON);
extractJSON(imageJSON);
}
@Override
protected String doInBackground(String... strings) {
String uri = strings[0];
BufferedReader bufferedReader = null;
try {
URL url = new URL(uri);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();
bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String json;
while ((json = bufferedReader.readLine()) != null) {
sb.append(json);
}
return sb.toString().trim();
} catch (Exception e) {
return null;
}
}
}
GetURLs gu = new GetURLs();
gu.execute(newurl);
}
但是,我想用下面的方法将json提取到一个新的JSON对象中,但抛出异常,Json对象没有创建。有什么想法发生这种异常吗?先感谢您!
private void extractJSON(String jsonString){
try {
JSONObject jsonObject = new JSONObject(jsonString);
JSONArray jArray = jsonObject.getJSONArray("results");
for (int i = 0; i < jArray.length(); i++) {
JSONObject oneObject = jArray.getJSONObject(i);
oneObject.getString("url");//
}
Log.e(LOGTAG, "JsonArray Succeed" );
} catch (JSONException e) {
e.printStackTrace();
Log.e(LOGTAG, "JsonArray exception");
}
}
而不是JSONArray jArray = jsonObject.getJSONArray("results");
尝试JSONArray jArray = new JSONArray (jsonObject.getString("results"));
你要的是一个json数组,但它是一个字符串。
json上有一个错误..在“结果”之后:一定不能有引号
这是对的
{"results":[{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara1.jpg\"},{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara2.jpg\"},{\"url\":\"https:\\\/\\\/augmentedandroidapp.000webhostapp.com\\\/images\\\/kamara3.jpg\"}]}