Android 4.2.2
I'm parsing a JSON string sent from PHP server. Parsing the same string gives this exception on random character number each time. Sometimes it's loaded successfully. The size of the input is 202858 bytes. I can't post it here as it's private data but I guess it's correctly formatted. If I run my app in debug/step-by-step mode it loads all the time! Also if the size of the response is smaller (fewer lines but not sure how many exactly) it also loads all the time.
Here is how I load the stream:
String JSONResp = "";
try {
URL u = new URL(params[1]);
HttpURLConnection conn = (HttpURLConnection) u.openConnection();
conn.setRequestMethod(params[0]);
conn.connect();
/* Here is the new code. This works! */
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"), 4096);
StringBuilder sb = new StringBuilder();
String line = null;
while( (line = br.readLine()) != null ) {
sb.append(line + "\n");
}
JSONResp = sb.toString();
/* Old code starts here. This is not working!
// Read the stream
InputStream is = conn.getInputStream();
byte[] b = new byte[4096];
ByteArrayOutputStream baos = new ByteArrayOutputStream();
while ( is.read(b) != -1) {
baos.write(b);
}
JSONResp = new String(baos.toByteArray());
*/
JSONArray arr = new JSONArray(JSONResp);
//TODO read result form the input stream
_HTTP_code = 200;
return arr;
}
catch(Throwable t) {
_HTTP_code = ERROR_Throwable;
_HTTP_text = "Error";
_HTTP_body = "Could not parse response!";
Log.e("JSON", "JSONResp.length() = " + JSONResp.length() + ".");
t.printStackTrace();
}
The code is executed from a separate thread and this is what I found in the Android documentation:
Instances of this class are not thread safe. Although this class is nonfinal, it was not designed for inheritance and should not be subclassed. In particular, self-use by overridable methods is not specified. See Effective Java Item 17, "Design and Document or inheritance or else prohibit it" for further information.
I'm not sure if I understand that text correctly but I don't have more than one thread querying the server at the same time.
Any help would be appreciated.
public class GetResultTask extends AsyncTask<String, Void, String> {
Activity act;
private ProgressDialog pd;
private boolean isInternetConnected = true;
public GetResultTask(Activity _act){
this.act = _act;
pd = ProgressDialog.show(act, null, "Loading...", true );
}
#Override
protected void onPreExecute() {
}
protected void onPostExecute(String result) {
pd.dismiss();
if(!isInternetConnected){
//Toast.makeText(getApplicationContext(), "Check your Network Connection", Toast.LENGTH_LONG).show();
}
}
#Override
protected String doInBackground(String... params) {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("option", "getPeople"));
nameValuePairs.add(new BasicNameValuePair("val", params[0]));
String downloadedString = null;
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://example.com/filename.php");
try {
// Execute HTTP Post Request
UrlEncodedFormEntity ent = new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8);
httppost.setEntity(ent);
//new
//HttpResponse response = httpClient.execute(httppost);
//System.out.println("Response");
HttpResponse response = httpclient.execute(httppost);
//System.out.println("Response is :-\n"+response);
InputStream in = response.getEntity().getContent();
StringBuilder stringbuilder = new StringBuilder();
BufferedReader bfrd = new BufferedReader(new InputStreamReader(in));
String line;
while((line = bfrd.readLine()) != null)
stringbuilder.append(line);
//string returned as JSON
downloadedString = stringbuilder.toString();
}
catch (ClientProtocolException e) {
e.printStackTrace();
} catch(UnknownHostException e){
isInternetConnected = false;
}
catch (IOException e) {
e.printStackTrace();
}catch (Exception e){
e.printStackTrace();
}
//System.out.println(downloadedString);
return downloadedString;
}
}
Related
In my CountryActivity.java I have a HttpRequest to retrieve json information of the wikipedia.
This is the code I use AsyncTask:
private class DownloadFilesTask extends AsyncTask<URL, Integer, String> {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&titles=Portugal");
protected String doInBackground(URL... urls) {
HttpResponse httpResponse = null;
try {
httpResponse = httpClient.execute(httpPost);
} catch (IOException e) {
e.printStackTrace();
}
HttpEntity httpEntity = httpResponse.getEntity();
try {
is = httpEntity.getContent();
} 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");
System.out.println(line);
}
is.close();
return sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String result) {
showDialog(Integer.parseInt("Downloaded "));
}
}
And, to call the class in my activity I use new DownloadFilesTask();.
The problem is, when I debug my private class, the debugger stops in the line HttpPost httpPost = new HttpPost("https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&titles=Portugal"); and it can't even retrieve the json. Do you know what may be happening? My app doesn't crash or nothing...
This is my logcat: https://pastebin.com/EgVrjfVx
Open connection to url with HttpURLConnection and set setRequestMethod() to GET
URL obj = new URL("https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&titles=Portugal");
HttpURLConnection http = (HttpURLConnection) obj.openConnection();
http.setRequestMethod("GET");
then gets its input stream and read via BufferedReader to your build.
BufferedReader reader = new BufferedReader(new InputStreamReader(http.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
reader.close();
String json_string = sb.toString(); // your json data
Check here full example to understand batter.
I'm trying to parse some JSON data that I'm receiving as response from a web url.
I'm getting the complete response, but when I read the response using BufferedReader, I get only partial data, I'm not able to read the entire contents of the response.
I've also tried writing the contents into a .txt file and again reading the contents from that file, but still it reads only partial dat, not the entire file contents.
Anyone has any solutions to this...
here is my code,
package com.example.asynctest;
/*I have excluded the imports*/
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new MyAsyncTask().execute();
}
class MyAsyncTask extends AsyncTask<String, String, Void>{
public String readBugzilla() {
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("https://bugzilla.mozilla.org/rest/bug?assigned_to=lhenry#mozilla.com");
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
/*I tried to Read the InputStream here, but it was incomplete, so I decided to write the contents of the inputstream into a text file, and then read the contents later on*/
String fileName = "category.txt";
File destinationFile = new File(getExternalFilesDir(null), fileName);
BufferedOutputStream buffer = new BufferedOutputStream(new FileOutputStream(destinationFile));
byte byt[] = new byte[100000];
int i;
for (long l = 0L; (i = content.read(byt)) != -1; l += i ) {
buffer.write(byt, 0, i);
}
buffer.close();
//Read text from file
File file = new File(getExternalFilesDir(null),"category.txt");
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
Log.d("Law", "line is "+line);
}
br.close();
Log.d("Law","Text is "+text.toString());
}
catch (IOException e) {
//You'll need to add proper error handling here
Log.d("Law IO", e.toString());
}
} else {
Log.e("Law", "Failed to download file");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return builder.toString();
}
#Override
protected Void doInBackground(String... arg0) {
// TODO Auto-generated method stub
String response = readBugzilla();
Log.d("Law", "Response "+response);
return null;
}
I really tried all that I can, but can't find a solution to this problem, perhaps someone has used a better technique to solve this.
I have a problem with HttpGet that I've searched on stackoverflow and on other websites, I even followed some examples but nothing to do, it doesn't work.
This is my code:
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://myurl.com/getit?token=" + _token);
HttpResponse response;
List<NameValuePair> params = new ArrayList<NameValuePair>();
String jsonString;
Gson gson;
Modules[] modulesList;
try {
response = client.execute(request);
//jsonString = EntityUtils.toString(response.getEntity());
//gson = new GsonBuilder().setPrettyPrinting().create();
//modulesList = gson.fromJson(jsonString, Modules[].class);
} catch (Exception e) {
System.out.println("FAIL: " + e.getMessage());
}
It always return a null pointer exception.
I've tried to display the URL, copy/paste in Chrome and the website does display my JSON.
The problem is quite clear in the first line of your stacktrace
/com.epitech.ferrei_j.epiandroid W/System.errīš android.os.NetworkOnMainThreadException 01-26
Post 2.3 Android you are not allowed to use the main UI thread to do tasks that can take a while to complete. Network IO is one of these.
You need to use an AsyncTask to execute the operation on its own thread.
See AsyncTask for examples on how to do this.
I usually write mine like this:
private String downloadUrl(String myurl) throws IOException {
InputStream is = null;
// Only display the first 500 characters of the retrieved
// web page content.
int len = 500;
try {
URL url = new URL(myurl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(READTIMEOUT /* milliseconds */);
conn.setConnectTimeout(CONNECTTIMEOUT /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
int response = conn.getResponseCode();
//check to read content body if 400 error and above occurs.
if (response >= HttpStatus.SC_BAD_REQUEST)
is = conn.getErrorStream();
else
is = conn.getInputStream();
// Convert the InputStream into a string
String contentAsString = readIt(is, len);
return contentAsString;
// Makes sure that the InputStream is closed after the app is
// finished using it.
} finally {
if (is != null) {
is.close();
}
}
}
public String readIt(InputStream stream, int len) throws IOException,
UnsupportedEncodingException {
// Reader reader = null;
// reader = new InputStreamReader(stream, "UTF-8");
// char[] buffer = new char[stream.available()];
// reader.read(buffer);
// return new String(buffer);
final BufferedReader r = new BufferedReader(new InputStreamReader(
stream));
final StringBuilder total = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
total.append(line);
}
return total.toString();
}
So all you have to do afterwards is :
jsonString = downloadUrl( "http://myurl.com/getit?token=" + _token );
I get Data from Json in android,date get and save in String Variable.but when use DecodeUrl its error:
Error: java.lang.IllegalArgumentException: Invalid % sequence at 40:
my code:
#SuppressLint("NewApi")
public String JsonReguest(String url) {
String json = "";
String result = "";
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
HttpClient httpclient = new DefaultHttpClient();
// Prepare a request object
HttpGet httpget = new HttpGet(url);
httpget.setHeader("Accept", "application/json");
httpget.setHeader("Content-Type", "application/json");
HttpResponse response;
try {
response = httpclient.execute(httpget);
response.setHeader("Content-Type","UTF-8");
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
result = convertStreamToString(instream);
InputStream stream = new ByteArrayInputStream(result.getBytes("UTF-8"));
result = convertStreamToString(stream);
// String encode_url=URLEncoder.encode(result,"UTF-8");
// String decode_url=URLDecoder.decode(encode_url,"UTF-8");
//result=decode_url;
//String decodedUrl = URLDecoder.decode(result, "UTF-8");
result=URLDecoder.decode(result);
}
} catch (Exception e) {
Log.e("Error", e.toString());
}
return result;
}
public static String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
simple text of json :
{"CategoryID":11,"ParentID":0,"Title":"%u062E%u0648%u062F%u0631%u0648","PicAddress":""},{"CategoryID":16,"ParentID":0,"Title":"%u0627%u0645%u0644%u0627%u0643%20","PicAddress":""}
this line crashed : result=URLDecoder.decode(result);
how to Resolve Problems.
first decode specifing your encoding
String result = URLDecoder.decode(url, "UTF-8");
and then go to http://json.org/, scroll down and choose one of the supported json parsing Java libraries
As Selvin commented %uxxxx is not a standard Url encoded string , so it's obvious to get an error
you have 2 options:
Contact the service provider to fix her url encoded strings and use URLDecoder.decode in your code
write a custom decoder for such strings
P.S. ask your questions more clear to avoid getting negative points
I'm aiming to make a very basic application which reads the HTML and stores it into a string. I'm only interested in one line from the website's source. I found a topic which suggested this:
String bodyHtml = "null";
try {
String myUri = "http://www.spring8.or.jp/ext/ja/status/text.html";
HttpClient httpClient = new DefaultHttpClient();
HttpGet get = new HttpGet(myUri);
HttpResponse response = httpClient.execute(get);
// Build up result
bodyHtml = EntityUtils.toString(response.getEntity());
} catch (Exception e) {
}
url.setText(bodyHtml);
With url being my textview. I have set the permissions in the manifest correctly as far as I'm aware.
However when I run this code on my phone and the emulator, it doesn't seem to work at all. I get nothing. Am I missing something?
Thank you
Try this instead of the EntityUtils
BufferedReader rd = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
String line = "";
String newLine = "";
while ((line = rd.readLine()) != null) {
newLine = newLine.concat(line);
}
System.out.println(newLine);
Try this,
Call the below method to download the HTml Content and pass the Url in the parameter,
private void downloadText(String urlStr) {
progressDialog = ProgressDialog.show(this, "",
"Download Text from " + urlStr);
final String url = urlStr;
new Thread () {
public void run() {
int BUFFER_SIZE = 2000;
InputStream in = null;
Message msg = Message.obtain();
msg.what=1;
try {
in = openHttpConnection(url);
InputStreamReader isr = new InputStreamReader(in);
int charRead;
text = "";
char[] inputBuffer = new char[BUFFER_SIZE];
while ((charRead = isr.read(inputBuffer))>0)
{
String readString =
String.copyValueOf(inputBuffer, 0, charRead);
text += readString;
inputBuffer = new char[BUFFER_SIZE];
}
Bundle b = new Bundle();
b.putString("text", text);
msg.setData(b);
in.close();
}catch (IOException e2) {
e2.printStackTrace();
}
messageHandler.sendMessage(msg);
}
}.start();
}
This the helper method which returns InputStream Object,
private InputStream openHttpConnection(String urlStr) {
InputStream in = null;
int resCode = -1;
try {
URL url = new URL(urlStr);
URLConnection urlConn = url.openConnection();
if (!(urlConn instanceof HttpURLConnection)) {
throw new IOException ("URL is not an Http URL");
}
HttpURLConnection httpConn = (HttpURLConnection)urlConn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
resCode = httpConn.getResponseCode();
if (resCode == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return in;
}
And now display the String in a textView using Handler,
private Handler messageHandler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case 1:
TextView text = (TextView) findViewById(R.id.textview01);
text.setText(msg.getData().getString("text"));
break;
}
progressDialog.dismiss();
}
};
Provide the INTERNET permission in the manifest.
In the execute method of the HttpClient, also put a HttpContext as you see below:
HttpContext localContext = new BasicHttpContext();
HttpResponse response = httpClient.execute(get, localContext);
And also use a BufferedReader:
final BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
If it doesn't work, you'll probably have a problem with you Internet connection.
BTW, don't forget about the android.permission.INTERNET permission!