Ok, what I want is to ask to my server for an url, and load that url on a WebView, but a problem appears: when you run a http request you need to do it in a separate thread, and loadUrl() needs to be runned in the UI thread. So, how can I do to first make the request and then load the url?
The code isn't inside an Activity, so I can't call runOnUiThread(Runnable).
How can I do it?
EDIT: As Alécio suggested, it's better to not have too much code inside custom views, so what I want to do is to create a method that allows me to pass the url when the app has received the response from the server. The code that I'm using for the request is:
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost("http://requesturl.com");
try {
HttpResponse response = client.execute(post);
InputStream content = response.getEntity().getContent();
String url = getStringFromInputStream(content);
//web.loadUrl(url);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
So, it's possible to know when a response has been received?
WebView is a UI component it must be in the context of an Activity or Fragment, so loadUrl() from the UI thread is OK.
If you want to make a server call, process the response before displaying something on the UI, then you might just use the conventional options to connect to a server URL using the HttpURLConnection. See the sample code below:
URL url = new URL("http://www.android.com/");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
readStream(in);
finally {
urlConnection.disconnect();
}
}
In this example, you really need to execute it in a background Thread. Never from the UI Thread.
Related
I followed this to Parse Json In Android
I have Successfully Done it with HttpData handler..
Here I am Successfully Posting Data to server and Getting Response..
Now I want to Use this same in the Part of HTTPS..
Can Any one suggest me How to do this Without Major Changes in my code.. Because In my application I am doing this for more activities.. Please Suggest me to Use HTTPs in my code..
I will provide Additional Info... Depending Responses...
Update
In my code I have Changed HttpURLConnection to HttpsURLConnection
Please suggest me How to through this error In my code..
Update 1
I have Changed Certificate on server side.. Now its working On Https..
But Now,
I want to Use HTTP and HTTPS Both in one app Depending on Client Requirement So here now its worked with Https....
But I also need to work with Http
In my Code Can any any one suggest me...I want I should Work with Https and Http Both In one App.
to use both HTTP and HTTPS, you need to have the 2 methods (i think you already have them)
GetHTTPData(String urlString)
GetHTTPSData(String urlString)
now in HTTPDataHandler class (where you have both methods above)
you need to create a 3rd method GetDataFromUrl(), that will check URL and decide which method to use (http or https)
public String GetDataFromUrl(String url){
if(url.toLowerCase().startsWith("https")){
//HTTPS:
return GetHTTPSData(url);
}else{
//HTTP:
return GetHTTPData(url);
}
}
now in the AsyncTask class ProcessJSON
replace this line stream = hh.GetHTTPData(urlString);
with this one stream = hh.GetDataFromUrl(urlString);
if you don't want to add that 3rd method in HTTPDataHandler, just use the if-statement in ProcessJSON at doInBackground() to call either one of the 2 methods (http or https)
You can use HttpsURLConnection, replace HttpURLConnection by HttpsURLConnection .
public String GetHTTPData(String urlString){
try{
URL url = new URL(urlString);
HttpsURLConnection urlConnection =(HttpsURLConnection)url.openConnection();
// Check the connection status
if(urlConnection.getResponseCode() == 200)
{
// if response code = 200 ok
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
// Read the BufferedInputStream
BufferedReader r = new BufferedReader(new InputStreamReader(in));
StringBuilder sb = new StringBuilder();
String line;
while ((line = r.readLine()) != null) {
sb.append(line);
}
stream = sb.toString();
// End reading...............
// Disconnect the HttpURLConnection
urlConnection.disconnect();
}
else
{
// Do something
}
}catch (MalformedURLException e){
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}finally {
}
// Return the data from specified url
return stream;
}
What I understand is in your server side, they used self signed SSL certificate. So you have to install that certificate in your android device also. Settings > Security > install form storage.But for production build you have to buy ssl certificate from CA Authorities.
Hope this will solve your problem.
Remove HttpDataHandler lines in doInBackground use HttpUrlConnection directly in doInBackground or use HttpUrlConnection in JSONparse class to post params to server follow this tutorial to post params Website
I need to send a JSON request similar to jQuery's ajax method.
The official documentation quote on the data parameter says:
If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting
So I have the same situation - a key that maps to an array "parameters":[123123, {"category":"123"}]
The complete data parameter looks like
$.ajax({
url: "/api/",
data: {"parameters":[123123, {"category":"123"}], "anotherParameter":"anotherValue"}
Would you mind telling how to achieve the same functionality in Java ?
UPD:
I've made it to work with the use of gson + collections + post request.
Here're some guide lines:
Sending POST requests in JAVA.
You might also want to consider performance issues related to different kinds of json parsers
What have you tried so far and what exactly is the problem? Is it that you don't know how to create a connection, that you don't know how to serialize your objects or that you don't know how to make the thing run asynchronously?
I don't think Java has any asynchronous HTTP call methods, you need to use a regular URLConnection and run it in a separate thread. The connection itself is formed like this:
URL url = null;
URLConnection urlConnection = null;
String myURL = "http://example.com/ajax.php?foo=bar";
try {
url = new URL(myURL);
urlConnection = url.openConnection();
} catch (Exception e) {
e.printStackTrace();
return;
}
InputStream responseStream = null;
try {
responseStream = urlConnection.getInputStream();
} catch (IOException e) {
e.printStackTrace();
return;
}
Then you must use something like the AsyncTask class to make it a background job.
For converting your objects to JSON you might want to use the GSON library.
How would one go about sending data back to server, from an android application?
I've already tried using HttpPost and posted back to a RESTful WCF service, but I couldnt get that to work (I've already created a SO question about this, without finding the solution..) - No matter what I do I keep getting 405 Method not allowed or the 400 Bad Request.. :(
I'm not asking for full code example necessarily.. just a pointer in a direction, which can enable me to send data back to a server.
It is important that the user should not have to allow or dismiss the transfer.. it should happen under the covers, so to speak
Thanks in advance
Services is the way to go. REST (I recommend this one on Android), or SOAP based. There're loads of tutorials on getting an android app communicate a service, even with .net / wcf ones.
Tho you can always just open raw sockets and send data with some custom protocol.
Edit:
Here's the doInBackground part of my asynctask handling http post communication, maybe that'll help:
protected String doInBackground(String... req) {
Log.d(TAG, "Message to send: "+req[0]);
HttpPost p = new HttpPost(url);
try{
p.setEntity(new StringEntity(req[0], "UTF8"));
}catch(Exception e){
e.printStackTrace();
}
p.setHeader("Content-type", "application/json");
String response = "";
try{
HttpResponse resp = hc.execute(p, localContext);
InputStream is = resp.getEntity().getContent();
response = convertStreamToString(is);
Log.d("Response", "Response is " + response);
} catch (Exception e){
e.printStackTrace();
}
return response;
}
I am making an app for Android. I like to make the rest calls as quick as possible. When I get my results as XML it takes 5 seconds (!) to get a simple xml like this:
<souvenirs>
<souvenir>
<id>1</id>
<name>Example 1</name>
<rating>3.4</rating>
<photourl>/images/example.jpg</photourl>
<price>3.50</price>
</souvenir>
<souvenir>
<id>2</id>
<name>Example 2</name>
<rating>2.4</rating>
<photourl>/images/example.jpg</photourl>
<price>8.50</price>
</souvenir>
</souvenirs>
So I tried it with JSON. But that takes also about 5 seconds to retrieve.
I load the XML in android with the following code:
URL url = new URL("http://example.nu?method=getAllSouvenirs");
URLConnection conn = url.openConnection();
long t=System.currentTimeMillis();
InputStream ins = conn.getInputStream();
Log.d("info", String.valueOf((System.currentTimeMillis()-t)));
The log says it takes about 5000 ms to get the inputstream.. Is there any way to speed this up? does anybody knows which technique the Android Market uses? This loads way faster than my app..
Thanks in advance! :)
When you try to get the data "manually" - via browser or via other means (wget, curl) how long does it take there.
On Android you also should take the mobile network into consideration that is usually significantly slower than for a desktop computer. Also latencies are bigger.
To me this sounds a lot like issues in the backend (e.g. trying to resolve the IP of the client and thus taking lots of time).
use Apache HttpClient instead of URLConnection:
Apache http client or URLConnection
EDIT(2012-02-07): no longer true on newer android platform please read: http://android-developers.blogspot.com/2011/09/androids-http-clients.html
Maybe that is how it is implemented and you can't do nothing. That is my guess.
My opinion is to do all connection based stuff on your own thread (to put in in background) and in foreground (main UI thread) entertain user. :)
I have played a little bit around this and it works fast enough for me... Here is my code:
private static HttpResponse doPost(String url, JSONStringer json) {
try {
HttpPost request = new HttpPost(url);
StringEntity entity;
entity = new StringEntity(json.toString());
entity.setContentType("application/json;charset=UTF-8");
entity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json;charset=UTF-8"));
request.setEntity(entity);
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
return response;
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return null;
}
And somewhere else I call that method like:
HttpResponse httpResponse = doPost(url, json);
BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"));
It works fine for me...
I need post data to server.
I use this code:
HttpClient client = new DefaultHttpClient();
try {
HttpPost httppost = new HttpPost(serverUrl);
StringEntity se = new StringEntity(data);
httppost.setEntity(se);
httppost.setHeader("Accept", "application/json");
httppost.setHeader("Content-type", "application/json");
// Execute HTTP Post Request
HttpResponse response = client.execute(httppost);
int statusCode = response.getStatusLine().getStatusCode();
Log.i(TVProgram.TAG, "ErrorHandler post status code: " + statusCode);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (client != null) {
client.getConnectionManager().shutdown();
}
}
But problem is that Android freeze on execute() method, application is blocked out and after some time Android tell me that application doesn't respond.
I tried to debug into SDK classes and it freeze in AbstractSessionInputBuffer class on the line 103 which is
l = this.instream.read(this.buffer, off, len);
I also tried it run the request in separated thread, but the same problem.
I tested it on Android 2.1 (emulator) and Android 2.2 real mobile device.
I also tried to set HTTP proxy and use Fiddler to check HTTP communication data are received by server and server also send correct answer and HTTP code 200. All seems to be ok.
What is wrong please?
UPDATE: When I use AndroidHttpClient which is part of Android 2.2 SDK it works great. But it is not in earlier version of Android. So I include it's source code in my app for now. But AndroidHttpClient use DefaultHTTPClient internally, so problem will be in configuration of DefaultHttpClient.
I am using a POST HTTP request successfully. Here is my code. I removed pieces using handler to display messages etc. and the handler itself.
The POST string is like "&NAME=value#NAME2=value2"...
protected class ConnectingThread implements Runnable
{
Message msg;
private Handler mExtHandler;
private String mData;
private String mUrl;
/**
* #param h (Handler) - a handler for messages from this thread
* #param data (String) - data to be send in HTTP request's POST
* #param url (String) - URL to which to connect
*/
ConnectingThread(Handler h, String data, String url) {
mExtHandler = h;
mData = data;
mUrl = url;
}
public void run() {
try {
// TODO use the handler to display txt info about connection
URL url = new URL(mUrl);
URLConnection conn = url.openConnection();
conn.setConnectTimeout(CONN_TIMEOUT_MILLIS);
conn.setDoOutput(true);
BufferedOutputStream wr = new BufferedOutputStream(conn.getOutputStream());
wr.write(mData.getBytes());
wr.flush();
wr.close();
String sReturn = null;
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
int length = conn.getContentLength();
char[] buffer = new char[length];
int read = rd.read(buffer);
if(read == length)
sReturn = new String(buffer);
rd.close();
buffer = null;
// TODO use the handler to use the response
} catch (Exception e) {
//....
}
// TODO use the handler to display txt info about connection ERROR
}
}
Isn't client.execute(httppost); synchronous ?
You probably need to put this in a thread, else it will freeze the UI.
Yes it is being freezed just becoz you haven't implemented this as Asynchronous process. Because while it makes web request, your UI will wait for the response and then it will be updated once the response is received.
So this should be implemented as Asynchronous process, and user should be notified (with progress bar or progress dialog) that there is something happening.
Now, Instead of implementing Runnable class, in android its preferrable and recommended to use AsyncTask, its also known as Painless Threading.
Do you background tasks inside the doInBackground() method.
Do your display type of operations inside onPostExecute() method, like updating listview with fetched data, display values inside TextViews....etc.
Display ProgressBar or ProgressDialog inside the onPreExecute() method.
Use AndroidHttpClient helped me in this situation.
But now complete AndroidHttpClient and DefaultHttpClient are obsolete in current version of Android so it is not important now.