Develop Reference

My program won't pass through HttpPost

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.

Send HTTP POST - Android

I know that this has been asked but most are out dated, and method are deprecated. I have found this solution,
new Thread( new Runnable() {
#Override
public void run() {
try {
String query = "param=" +"item"+"&other="+"num";
URL url = new URL("http://www.url.com/url_post.php");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
//Set to POST
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setReadTimeout(10000);
Writer writer = new OutputStreamWriter(connection.getOutputStream());
writer.write(query);
writer.flush();
writer.close();
} catch (Exception e) {
// TODO Auto-generated catch block
Log.e(TAG, e.toString());
}
}
}).start();
But, it does not provide how to get data that is returned for example, I am return some JSON, where get I get that data that is returned?
Thanks for the help :)

Do this
//Get Response
InputStream is = connection.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
String line;
StringBuffer response = new StringBuffer();
while((line = rd.readLine()) != null) {
response.append(line);
response.append('\r');
Finally in response you will get response JSON string then do what you want to do.
For more details visit this link
http://www.xyzws.com/javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139

I recommend you to use this project as library:
https://github.com/matessoftwaresolutions/AndroidHttpRestService
It's extremely easy and I use it for all my projects. I commited it to Github because it is difficult for me to find an easy Rest client for general purpose.
I'm going to commit an update for integration with Android Studio ASAP.
I hope it helps!!

InputStream in = connection.getInputStream();
JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8"));

Add this part after your writer.close()
connection.connect();
int statusCode = connection.getResponseCode();
Log.d("ON POST", " The status code is " + statusCode);
if (statusCode == 200) {
is = new BufferedInputStream(connection.getInputStream());
String response = convertInputStreamToString(is);
Log.d("ON POST", "The response is " + response);
return response;
} else {
Log.d("ON POST", "On Else");
return "";
}
The ConvertInputStreamToString() should be created to return your json as string
public static String convertInputStreamToString(InputStream in) {
BufferedReader reader = null;
StringBuffer response = new StringBuffer();
try {
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
response.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return response.toString();
}

How to Decode String in Java or android?

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

HttpResponse and BufferedReader

I am trying to read the buffer (android application) and set the value to my TextView 'httpStuff'. But i dont think i am getting some response from the URI.
I don't get any runtime errors. I tried many flavour of the same logic. Nothing seems to be working.
INTERNET permission is already set in the manifest. SdkVersion="15". Any help ?
HttpClient client = new DefaultHttpClient();
URI website = new URI("http://www.mybringback.com");
HttpGet request = new HttpGet();
request.setURI(website);
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
InputStream is = entity.getContent();
BufferedReader in = new BufferedReader(new InputStreamReader(is));
httpStuf.setText( in.readLine());

I think you are missing the while loop and also, when you say only in.readLine(), may be it is returning you an empty line from the response, though it is having enough data.So make sure to read the reader entirely like this and check its contents.
while ((line = rd.readLine()) != null) {
httpStuf.setText(line+"\r\n");
}
Hope this will help you.

This code worked for me
InputStream is = response.getEntity().getContent();
String strResponse = inputStreamToString(is);
private String inputStreamToString(InputStream is)
{
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is), 1024 * 4);
// Read response until the end
try
{
while ((line = rd.readLine()) != null)
{
total.append(line);
}
} catch (IOException e)
{
Log.e(TAG, "error build string" + e.getMessage());
}
// Return full string
return total.toString();
}

try to get the status code of response and Then you can compare with the (HTTP status)
int responseCode=response.getStatusLine().getStatusCode()

I am using this method to simply catch the HTTP response and it works fine for me.
public String httpGetResponse(String url) {
try {
Log.i("HTTP Request", "httpGet Request for : " + url);
DefaultHttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet(url);
//get.setHeader("Connection", "keep-alive");
HttpResponse response = client.execute(get);
InputStream is = response.getEntity().getContent();
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(is));
StringBuilder str = new StringBuilder();
String line = null;
while ((line = bufferedReader.readLine()) != null) {
str.append(line + "\n");
}
return str.toString();
} catch (Exception e) {
Log.e("HTTP error", "Error in function httpGetResponse : "
+ e.getMessage());
return null;
}
}

Source Code html doesn't download completly

I try to get HTML content, everything works find except 1 thing. It doesn't download whole code and skip the content which I want to extract(urls to images, names) and I have just blank classes 'obrazek'.
Here is the code i use to get source code:
String SourceCode(String adres) throws IllegalStateException, IOException
{
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpGet httpGet = new HttpGet(adres);
HttpResponse response = null;
try {
response = httpClient.execute(httpGet, localContext);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader reader = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()
)
);
String result = "";
while(reader.readLine() != null)
{
result += reader.readLine();
}
reader.close();
return result;
Thank you for help:)

You skip one line each time. should be
StringBuilder result = new StringBuilder();
String line;
while((line = reader.readLine()) != null)
{
result.append(line);
}
reader.close();
return result.toString();
BTW - I used StringBuilder to avoid creation of new String object each iteration - very recommended.