我的应用在尝试解析Instagram JSON时崩溃了。我在这里做错了什么？
public class InstagramActivity extends BaseActivity {
static String url;
static ArrayList<String> thumbnailURLS;
static ArrayList<String> standardURLS;
static Context context;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_grid);
context = getApplicationContext();
getActionBar().setTitle("Instagram");
url = "https://api.instagram.com/v1/users/1373666362/media/recent/?client_id=a2b04732b52d43c99fe453a8ca2a5512&count=50";
thumbnailURLS = new ArrayList<String>();
standardURLS = new ArrayList<String>();
new ParseJSON().execute();
}
public static class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser()
{
}
public JSONObject getJSONFromUrl(String jsonUrl)
{
// Making HTTP request
try
{
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(jsonUrl);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
catch (ClientProtocolException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
is.close();
json = sb.toString();
}
catch (Exception e)
{
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try to parse the string to a JSON object
try
{
jObj = new JSONObject(json);
}
catch (JSONException e)
{
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
public static class ParseJSON extends AsyncTask<Void,Void,ArrayList> {
@Override
protected void onPreExecute()
{
// TODO Auto-generated method stub
super.onPreExecute();
}
@Override
protected ArrayList doInBackground(Void... params) {
JSONParser jParser = new JSONParser();
// get json from url here
JSONObject json = jParser.getJSONFromUrl(url);
try {
JSONArray dataArray = json.getJSONArray("data");
int thumbnailsCount = dataArray.length();
for (int i = 0; i < thumbnailsCount; i++) {
JSONObject imagesObject = dataArray.getJSONObject(i).getJSONObject("images");
String thumbURL = imagesObject.getJSONObject("thumbnail").getString("url");
thumbnailURLS.add(thumbURL);
}
}
catch (Exception e) {
e.getMessage().toString();
}
return thumbnailURLS;
}
@Override
protected void onPostExecute(ArrayList result) {
super.onPostExecute(result);
for (String thumb : thumbnailURLS) {
System.out.println(thumb);
}
}
}
}
它捕获JSONException
E/JSON Parser﹕ Error parsing data org.json.JSONException: End of input at character 0 of
和
E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #2
这是NULL。 JSONObject json = jParser.getJSONFromUrl(url);
以下是一些预期的JSON。
{
"pagination": {
"next_url": "https://api.instagram.com/v1/users/1373666362/media/recent?access_token=25320296.1fb234f.b797e861c2494059b6584ac9749208fe&count=2&max_id=791341826737262101_1373666362",
"next_max_id": "791341826737262101_1373666362"
},
"meta": {
"code": 200
},
"data": [
{
"attribution": null,
"tags": [
"kystatefair"
],
"type": "image",
"location": null,
"comments": {
"count": 0,
"data": []
},
"filter": "Amaro",
"created_time": "1408648864",
"link": "http://instagram.com/p/r-MuYWFU96/",
"likes": {
"count": 5,
"data": [
{
"username": "tayworthington_",
"profile_picture": "http://photos-g.ak.instagram.com/hphotos-ak-xaf1/10632550_835588266460870_765781001_a.jpg",
"id": "24471760",
"full_name": "τᎯϓιΘર"
},
{
"username": "renee_laurent",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_407687505_75sq_1397913189.jpg",
"id": "407687505",
"full_name": "Renee Laurent"
},
{
"username": "kystatefair",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_381460857_75sq_1396983015.jpg",
"id": "381460857",
"full_name": "kystatefair"
},
{
"username": "jennaharrod1",
"profile_picture": "http://photos-b.ak.instagram.com/hphotos-ak-xfa1/10665605_1495839117327497_809128971_a.jpg",
"id": "18591399",
"full_name": "Jenna Harrod"
}
]
},
"images": {
"low_resolution": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598650_352432021574566_306460147_a.jpg",
"width": 306,
"height": 306
},
"thumbnail": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598650_352432021574566_306460147_s.jpg",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598650_352432021574566_306460147_n.jpg",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1408648864",
"text": "Congratulations to The Lindsey Family for winning the Gospel Quartet competition! #kystatefair",
"from": {
"username": "kyfarmbureau",
"profile_picture": "http://photos-b.ak.instagram.com/hphotos-ak-xpf1/10349740_650479825030913_1755233568_a.jpg",
"id": "1373666362",
"full_name": "Kentucky Farm Bureau"
},
"id": "792126548887293629"
},
"user_has_liked": false,
"id": "792126548258148218_1373666362",
"user": {
"username": "kyfarmbureau",
"website": "",
"profile_picture": "http://photos-b.ak.instagram.com/hphotos-ak-xpf1/10349740_650479825030913_1755233568_a.jpg",
"full_name": "Kentucky Farm Bureau",
"bio": "",
"id": "1373666362"
}
},
{
"attribution": null,
"tags": [
"kfbmtc"
],
"type": "image",
"location": null,
"comments": {
"count": 0,
"data": []
},
"filter": "Normal",
"created_time": "1408555318",
"link": "http://instagram.com/p/r7aTLelU4V/",
"likes": {
"count": 4,
"data": [
{
"username": "corkey_cole",
"profile_picture": "http://photos-e.ak.instagram.com/hphotos-ak-xaf1/10598220_490230854445140_2139881142_a.jpg",
"id": "324166968",
"full_name": "corkey_cole"
},
{
"username": "renee_laurent",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_407687505_75sq_1397913189.jpg",
"id": "407687505",
"full_name": "Renee Laurent"
},
{
"username": "silveradomafia04",
"profile_picture": "http://photos-e.ak.instagram.com/hphotos-ak-xfa1/914483_1500860143488988_1771984176_a.jpg",
"id": "1006562558",
"full_name": "Gideon Bailey"
},
{
"username": "sharelouisville",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_1302605134_75sq_1399019203.jpg",
"id": "1302605134",
"full_name": "Share Louisville"
}
]
},
"images": {
"low_resolution": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598436_1456586981280578_133918080_a.jpg",
"width": 306,
"height": 306
},
"thumbnail": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598436_1456586981280578_133918080_s.jpg",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "http://scontent-a.cdninstagram.com/hphotos-xaf1/t51.2885-15/10598436_1456586981280578_133918080_n.jpg",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1408555318",
"text": "Media is starting to crowd around for #kfbmtc",
"from": {
"username": "kyfarmbureau",
"profile_picture": "http://photos-b.ak.instagram.com/hphotos-ak-xpf1/10349740_650479825030913_1755233568_a.jpg",
"id": "1373666362",
"full_name": "Kentucky Farm Bureau"
},
"id": "791341827391573199"
},
"user_has_liked": false,
"id": "791341826737262101_1373666362",
"user": {
"username": "kyfarmbureau",
"website": "",
"profile_picture": "http://photos-b.ak.instagram.com/hphotos-ak-xpf1/10349740_650479825030913_1755233568_a.jpg",
"full_name": "Kentucky Farm Bureau",
"bio": "",
"id": "1373666362"
}
}
]
}
更新：问题似乎与Instagram api url我使用isn不给我JSON。我想这可能是因为我使用的是client_id而不是获取访问令牌。有谁知道是否是这种情况？我使用了其他我认为不需要访问令牌的JSON URL，它返回了JSON就好了。
答案 0 :(得分：2)
我更新了您的方法getJSONFromUrl，如下所示：
问题在于，服务器返回405表示method not allowed。您正在使用POST来访问此服务器不允许的数据。您必须在此处使用GET才能获得成功请求。
你的其余代码工作正常。
您可以更新下面的代码来添加一个默认情况，您可以返回一个有效的常量json字符串，其中包含一条可以避免应用程序崩溃的消息，还可以添加其他情况，如404和405，并返回一个有效的json适当的消息，适合用户理解。
public JSONObject getJSONFromUrl(String jsonUrl)
{
HttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet(jsonUrl);
String responseBody = "DEFAULT_MSG_TEXT";
int resCode = 0;
try{
HttpResponse response = client.execute(get);
int responseCode = response.getStatusLine().getStatusCode();
resCode = responseCode;
switch(responseCode) {
case 200:
HttpEntity entity = response.getEntity();
if(entity != null) {
responseBody = EntityUtils.toString(entity);
}
break;
}
}
catch(Exception ex){
Log.e("Post Error",resCode + "\n Exception" + ex);
responseBody = "DEFAULT_MSG_TEXT";
}
json = responseBody;
// try to parse the string to a JSON object
try
{
jObj = new JSONObject(json);
}
catch (JSONException e)
{
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
试试这个让我知道!!!