Get Website text from URL into String (Android) - java

first of all I have to say that I'm a beginner in Android programing and not very experienced in general programing at all. But now I decided to make a little app for my private use.
In my app I need to get some Text from a given URL into a string. I found some methods on the web and personalized them a bit. But there is something wrong because when I run the app with the Android Eclipse emulator it says "Unfortunately, xxx_app has stopped.".
Here is my code:
public String getURLtext(String zielurl) throws IllegalStateException, IOException{
String meineurl = zielurl;
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpGet httpGet = new HttpGet(meineurl);
HttpResponse response = httpClient.execute(httpGet, localContext);
String result = "";
BufferedReader reader = new BufferedReader(
new InputStreamReader(
response.getEntity().getContent()
)
);
String line = null;
while ((line = reader.readLine()) != null){
result += line + "\n";
}
return result;
}
And this is the method where I want to show the output string in my EditText text1.
public void test(View view) throws InterruptedException, ExecutionException, IllegalStateException, IOException {
EditText text1 = (EditText)findViewById(R.id.textfeld);
String teststring = getURLtext("http://ephemeraltech.com/demo/android_tutorial20.php");
text1.setText(teststring);
}
I would be happy if anyone can help me with this.
Thanks!

Your code looks good until you get the HTTPResponse, the bottom part (response to string) can be optimized a lot. It's also worth noticing that Android won't let you to do network operation on the main thread, so please consider using an AsyncTask to execute your http GET operation.
public String getURLtext(String zielurl) throws IllegalStateException, IOException
{
String result = ""; // default empty string
try
{
String meineurl = zielurl;
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpGet httpGet = new HttpGet(meineurl);
HttpResponse response = httpClient.execute(httpGet, localContext);
InputStream is = response.getEntity().getContent();
result = inputStreamToString(is).toString();
}
catch (Exception ex)
{
// do some Log.e here
}
finally
{
return result;
}
}
// Fast Implementation
private StringBuilder inputStreamToString(InputStream is) {
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
// Read response until the end
try {
while ((line = rd.readLine()) != null) {
total.append(line);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// Return full string
return total;
}

Related

Android HttpGet doesn't work

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 );

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

Android: Reading the HTML from a website and posting it to the screen

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!

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.

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