Develop Reference

Can't downloading HTML in Android Studio

When I'm trying to download html using this method:
public class DownloadHtml extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpURLConnection connection = null;
try {
url = new URL(urls[0]);
connection = (HttpURLConnection) url.openConnection();
InputStream inputStream = connection.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
int data = reader.read();
while (data != -1) {
char currentChar = (char) data;
result += currentChar;
data = reader.read();
}
return result;
} catch (Exception e) {
e.printStackTrace();
return "Failed";
}
}
}
And logging a result
DownloadHtml downloadHtml = new DownloadHtml();
String result = null;
try {
result = downloadHtml.execute("http://stackoverflow.com").get();
} catch (Exception e) {
e.printStackTrace();
}
Log.i("Html", result);
I am gettin only small part of it.
Is there a way to get whole HTML of webpage?

Solution was simple. Looks like Log.i doesn't print everything in one go.
When I have tried to get all the links from HTML they were successfully printed.

How to get full video download from a link?

I am trying to download a video from a link, but it only downloads a small part of it, so it can't be watched at all. How would you download an entire video no matter how large the file is from a link?
try {
URL url;
byte[] buf;
int byteRead, byteWritten = 0;
url = new URL(fAddress);
outStream = new BufferedOutputStream(new FileOutputStream(destinationDir + "\\" + localFileName));
conn = url.openConnection();
is = conn.getInputStream();
buf = new byte[size];
while ((byteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, byteRead);
byteWritten += byteRead;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
is.close();
outStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

It looks like server may redirect you to other location which your code doesn't handle. To get final location you can try method like (based on: http://www.mkyong.com/java/java-httpurlconnection-follow-redirect-example/):
public static String getFinalLocation(String address) throws IOException{
URL url = new URL(address);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
int status = conn.getResponseCode();
if (status != HttpURLConnection.HTTP_OK)
{
if (status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM
|| status == HttpURLConnection.HTTP_SEE_OTHER)
{
String newLocation = conn.getHeaderField("Location");
return getFinalLocation(newLocation);
}
}
return address;
}
Now you simply need to change
url = new URL(fAddress);
to
url = new URL(getFinalLocation(fAddress));

Android 2.1 appears to not flush output stream

We are getting some very weird behavior in Android. Our network stack (that talks to a REST server) works fine in almost all situations, except when we do a GET shortly after doing a larger POST. What appears to be happening is that the Output stream is not flushing, and ends up sending the last line that was in there when the new socket is opened. Please note, each connection is a new object created, so this is unexpected behavior. First, the error code that seems to point me to the output stream, these are from the server logs.
10.1.8.195 - - [07/Nov/2012:13:36:28 -0700] "POST /iou/lender HTTP/1.1" 200 28 "-" "Android"
10.1.8.195 - - [07/Nov/2012:13:36:36 -0700] "------------V2ymHFg03ehbqgZCaKO6jy" 400 173 "-" "-"
That attempt after should be a GET that then pulls the data from the server that includes the new entry added via the POST. However, all we get is again what appears to be the last line from the output stream from the POST. Here is our core code for the network stack, if more of the surrounding code is needed, let me know.
public Object serverConnect(String url, String method,
Hashtable<String, Object> params) {
HttpConnection c = null;
InputStream is = null;
OutputStream out = null;
ByteArrayOutputStream postDataByteArrayImage = new ByteArrayOutputStream();
byte[] data;
String boundry = "----------V2ymHFg03ehbqgZCaKO6jy";
try {
if (!url.startsWith("/")) {
url = "/" + url;
}
String uri = Control.URL_Secure + Control.dtserver + ":"
+ Control.port + url;
ByteArrayOutputStream postDataByteArray = new ByteArrayOutputStream();
params.put("sessionId", Control.sessionId);
if (method.equals("GET")) {
uri = uri + "?";
Enumeration enumParams = params.keys();
while (enumParams.hasMoreElements()) {
if (!uri.endsWith("?")) {
uri = uri + "&";
}
String key = (String) enumParams.nextElement();
uri = uri
+ key
+ "="
+ java.net.URLEncoder.encode((String) params
.get(key));
}
} else if (method.equals("POST")) {
Enumeration enumParams = params.keys();
postDataByteArray.write(("--").getBytes());
postDataByteArray.write((boundry).getBytes());
postDataByteArray.write(("\r\n").getBytes());
while (enumParams.hasMoreElements()) {
String key = (String) enumParams.nextElement();
if (!key.equals("image")){
postDataByteArray
.write(("Content-Disposition: form-data; name=\"")
.getBytes());
postDataByteArray.write((key).getBytes());
postDataByteArray.write(("\"").getBytes());
postDataByteArray.write(("\r\n\r\n").getBytes());
postDataByteArray.write(((String) params.get(key))
.getBytes());
postDataByteArray.write(("\r\n").getBytes());
postDataByteArray.write(("--").getBytes());
postDataByteArray.write(boundry.getBytes());
postDataByteArray.write(("\r\n").getBytes());
}
}
postDataByteArray.close();
}
Log.i("URL", uri);
URL urltoConenct = new URL(uri);
URLConnection connection = urltoConenct.openConnection();
HttpURLConnection urlConnection = (HttpURLConnection) connection;
URLConnection.setDefaultRequestProperty("Method", method); // default
urlConnection.setRequestProperty("User-Agent", "Android");
if (method.equals("POST")) {
urlConnection.setDoOutput(true);
urlConnection.setFixedLengthStreamingMode(postDataByteArray.toByteArray().length + postDataByteArrayImage.toByteArray().length);
urlConnection.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + boundry);
out = urlConnection.getOutputStream();
out.write(postDataByteArray.toByteArray());
out.write(postDataByteArrayImage.toByteArray());
out.close();
}
int response = 0;
try {
response = urlConnection.getResponseCode();
} catch (IOException e) {
if (e.toString()
.equals("java.io.IOException: Received authentication challenge is null"))
throw new RESTException(401, "Invalid Phone or Pin");
else
throw e;
}
if (response == HttpURLConnection.HTTP_OK) {
is = urlConnection.getInputStream();
if (is == null) {
return new IOException(
"Cannot open HTTP InputStream, aborting");
}
ByteArrayOutputStream bo = new ByteArrayOutputStream();
int ch;
int count = 0;
while ((ch = is.read()) != -1) {
bo.write(ch);
count++;
}
data = bo.toByteArray();
return new String(data);
} else if (response == 500) {
return new RESTException(500, "Internal server error");
} else {
RESTException x = new RESTException();
x.setCode(response);
try {
is = urlConnection.getInputStream();
if (is == null) {
x.setMessage("Unable to retrieve message");
return x;
}
ByteArrayOutputStream bo = new ByteArrayOutputStream();
int ch;
int count = 0;
while ((ch = is.read()) != -1) {
bo.write(ch);
count++;
}
data = bo.toByteArray();
String output = new String(data);
JSONObject obj;
try {
obj = new JSONObject(output);
JSONObject err = obj.getJSONArray("errors")
.getJSONObject(0);
x.setMessage(err.getString("message"));
} catch (JSONException e) {
Log.e("stuff", output);
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e) {
// Damn you android! I'm using a REST service here, stop
// trying to interpret my errors!
x.setMessage("Unable to retrieve message");
}
return x;
}
} catch (Exception x) {
x.printStackTrace();
/*
* if (!retried && x.toString().equals(
* "java.io.IOException: Persistent connection dropped after first chunk sent, cannot retry"
* )) { retry = true; } if (!retry) { return x; }
*/
return x;
} finally {
try {
out.close();
} catch (Exception x) {
}
try {
is.close();
} catch (Exception x) {
}
try {
c.close();
} catch (Exception x) {
}
params.clear();
}
// return null;
}

After a very long time of frustration, we discovered that Android tries to keep a connection alive even if you manually call .close() on the connection. This worked fine for our GET methods, but POST methods left the socket in a state that it couldn't then process a GET. Adding the following fixed all our problems:
urlConnection.setRequestProperty("connection", "close");

The http connection freeze when using mobile netwotk

I am trying to make http request on blackberry platform, My problem is: When I make connection via WiFi it works good, but when I use mobile network it doesn't work and the connection freeze
Here is my code
public static String getHttpUTFResponse(String url) {
url = addConnSuffex(url);
HttpConnection connection = null;
byte responseData[] = null;
try {
connection = (HttpConnection) new ConnectionFactory()
.getConnection(url).getConnection();
int len = (int) connection.getLength();
System.out.println(len);
if (len != -1) {
responseData = new byte[len];
DataInputStream dis;
dis = new DataInputStream(connection.openInputStream());
dis.readFully(responseData);
dis.close();
}
} catch (IOException e) {
System.out.println("Connection Error");
} finally {
if (connection != null) {
try {
connection.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
connection = null;
}
}
if (responseData != null) {
try {
return new String(responseData, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return null;
}
} else {
return null;
}
}
public static String addConnSuffex(String url) {
ServiceBook sb = ServiceBook.getSB();
ServiceRecord[] records = sb.findRecordsByCid("WPTCP");
String uid = null;
if (records == null) {
return url;
}
for (int i = 0; i < records.length; i++) {
if (records[i].isValid() && !records[i].isDisabled()) {
if (records[i].getUid() != null
&& records[i].getUid().length() != 0) {
if ((records[i].getUid().toLowerCase().indexOf("wifi") == -1)
&& (records[i].getUid().toLowerCase()
.indexOf("mms") == -1)) {
uid = records[i].getUid();
break;
}
}
}
}
if (DeviceInfo.isSimulator()) {
return url;
}
if (uid != null) {
// open a WAP 2 connection
url = url + ";deviceside=true;ConnectionUID=" + uid;
System.out.println("**************** on conn" + url);
} else {
url = url + ";deviceside=true;interface=wifi";
// Consider another transport or alternative action.
}
System.out.println("**************** on conn" + url);
return url;
}
Thanks a lot

For network connection TransportDetective.class is more use full you can resolve lot of problem related to network.
TransportDetective y URLFactory para configurar la conexion a web
Different ways to make an HTTP or socket connection

how to resume an interrupted download

I'm trying to download a large file from my Yahoo! web site server which apparently is setup (not by me) to disconnect downloads if they are not completed within 100 seconds. The file is small enough to usually successfully transfer. On the occasions when the data rate is slow and the download gets disconnected, is there a way to resume the URLConnection at the file offset where the disconnection occurred? Here's the code:
// Setup connection.
URL url = new URL(strUrl[0]);
URLConnection cx = url.openConnection();
cx.connect();
// Setup streams and buffers.
int lengthFile = cx.getContentLength();
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(strUrl[1]);
byte data[] = new byte[1024];
// Download file.
for (total=0; (count=input.read(data, 0, 1024)) != -1; total+=count) {
publishProgress((int)(total*100/lengthFile));
output.write(data, 0, count);
Log.d("AsyncDownloadFile", "bytes: " + total);
}
// Close streams.
output.flush();
output.close();
input.close();

Try using a "Range" request header:
// Open connection to URL.
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
// Specify what portion of file to download.
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
// here "downloaded" is the data length already previously downloaded.
// Connect to server.
connection.connect();
Having done that, you can seek at a given point (just before the length of your download data, say X) and start writing the newly downloaded data there. Be sure to use the same value X for the range header.
Details about 14.35.2 Range Retrieval Requests
More details and source code can be found here

Here's an example code that you can use:
import java.io.*;
import java.net.*;
public class HttpUrlDownload {
public static void main(String[] args) {
String strUrl = "http://VRSDLSCEN001:80//DLS//lib//clics.jar";
String DESTINATION_PATH = "clics.jar";
int count = 0;
while (true) {
count++;
if (download(strUrl, DESTINATION_PATH) == true || count > 20) {
break;
}
}
}
public static boolean download(String strUrl, String DESTINATION_PATH) {
BufferedInputStream in = null;
FileOutputStream fos = null;
BufferedOutputStream bout = null;
URLConnection connection = null;
int downloaded = 0;
try {
System.out.println("mark ... download start");
URL url = new URL(strUrl);
connection = url.openConnection();
File file=new File(DESTINATION_PATH);
if(file.exists()){
downloaded = (int) file.length();
}
if (downloaded == 0) {
connection.connect();
}
else {
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
connection.connect();
}
try {
in = new BufferedInputStream(connection.getInputStream());
} catch (IOException e) {
int responseCode = 0;
try {
responseCode = ((HttpURLConnection)connection).getResponseCode();
} catch (IOException e1) {
e1.printStackTrace();
}
if (responseCode == 416) {
return true;
} else {
e.printStackTrace();
return false;
}
}
fos=(downloaded==0)? new FileOutputStream(DESTINATION_PATH): new FileOutputStream(DESTINATION_PATH,true);
bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int x = 0;
while ((x = in.read(data, 0, 1024)) >= 0) {
bout.write(data, 0, x);
}
in.close();
bout.flush();
bout.close();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
}
}
if (bout != null) {
try {
bout.close();
} catch (IOException e) {
}
}
if (connection != null) {
((HttpURLConnection)connection).disconnect();
}
}
}
}