Develop Reference

No response from HTTP request

i have written an android app which post data to my database. The app should access an webservice which post the data to the database. the webservice works fine. ive testet it with my browser, he is already on the server. now i want my app to execute the webservice. but that doesnt work. My debugger doesnt work too so im not able to debug. here is my code to for accessing the webservice. any ideas??
public class PostBlog extends AsyncTask<String, Void, String> {
String BlogURL;
public PostBlog(String insertBlogURL) {
BlogURL = insertBlogURL;
}
#Override
protected String doInBackground(String... params) {
postBlogData(BlogURL);
return null;
}
public void postBlogData(String url) {
String result = "";
//the year data to send
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("year", "1980"));
//http post
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
InputStream is = entity.getContent();
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");
}
is.close();
result = sb.toString();
} catch (Exception e) {
//(TextView)rootView.findViewById(R.id.question)
Log.e("log_tag", "Error converting result " + e.toString());
}
}
}
The Class is called from my main Activity by
new PostBlog(insertBlogURL).execute("");
Is there another easier way to execute my ".jsp?asdd=sdsd" file on the server?
Thanks for your ideas.

Instead of doing :
new PostBlog(insertBlogURL).execute("");
Change your constructor and retrieve the url from the doInBackground method, by doing params[0]
Then initiate the download like this
PostBlog blogPoster = new PostBlog();
try {
blogPoster.execute(insertBlogURL);
} catch (InterruptedException e) {} catch (ExecutionException e) {}
I should say this is a modified snippet of code from my own project, so it might not work exactly the way you expect.

HTTPResponse's string from Play is empty

I am using Play and Faye on my Server. Play is used for API calls, while Faye is used for communication with the clients.
So, I have this method in the server:
public static Result broadcast(String channel, String message)
{
try
{
FayeClient faye = new FayeClient("localhost");
int code = faye.send(channel, message);
// print the code (prints 200).
return ok("Hello"); <------------ This is what we care about.
}
catch(Exception e)
{
return ok("false");
}
}
this is the code on the client, which is an android phone.
(it's the HTTP post method, which sends something to the server and gets a response back
The problem is, I can't print the message of the response.
public static String post(String url, List<BasicNameValuePair> params)
{
HttpClient httpclient = new DefaultHttpClient();
String result = "";
// Prepare a request object
HttpPost httpPost;
httpPost = new HttpPost(url);
httpPost.setHeader("Content-type", "application/json");
httpPost.setHeader("Accept", "application/json");
JSONObject obj = new JSONObject();
try
{
for (NameValuePair pair : params)
obj.put(pair.getName(), pair.getValue());
}
catch (JSONException e)
{
return e.getMessage();
}
// Add your data
try
{
httpPost.setEntity(new StringEntity(obj.toString(), "UTF-8"));
}
catch (UnsupportedEncodingException e)
{
return e.getMessage();
}
HttpResponse httpResponse;
try
{
httpResponse = httpclient.execute(httpPost);
// Get hold of the response entity
HttpEntity entity = httpResponse.getEntity();
String str = EntityUtils.toString(entity);
Log.e("RestClient", "result = \"" + str + "\""); // hello should be printed here??
}
catch(Exception e)
{
// ...
}
The problem is that in logcat, what is printed is [result = ""]. Am I doing something wrong?
Thank you.

Use a tool such as Fiddler and see what the HTTP response contains.

Optimizing HTTP requests in android

I have noticed that my http requests tend to take alot of time compared apps communicating with same server. It makes my app feel sluggish and I was wondering if there is a better way of making these requests and updating the UI.
At the moment I use this method to make post requests
public String postRequest(List<NameValuePair> nameValuePairs, String method_name) {
String result = "";
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.mysite.com/api/"+method_name);
httppost.setHeader("Accept", "application/json");
httppost.setHeader("Authorization", "Basic somestuff");
try {
// Add your data
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
BufferedReader rd = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
result = rd.readLine();
return result;
} catch (ClientProtocolException e) {
} catch (IOException e) {
}
return null;
}
And in my UI thread (i.e my Fragment classes) I use this in an Async Task like this
class MakeRequest extends AsyncTask<Integer, Integer, String> {
protected String doInBackground(Integer... counter) {
String result = "";
String method_name = "";
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", value));
nameValuePairs.add(new BasicNameValuePair("name", name));
method_name = "petition/setPetition";
result = fixr.postRequest(nameValuePairs, method_name);
JSONObject jsonFile = new JSONObject(result);
if(!jsonFile.has("error")){
//Parse JSON using GSON
return "success";
}else{
return jsonFile.getString("error");
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String jsonResult) {
try {
if(jsonResult != null){
//update UI
}else{
//Error message
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
I'd like to optimize this so users can have a really smooth experience on my application. I'm open to using third party http libraries or is there also an argument against using AysncTasks and maybe the runOnUiThread() instead.

Volley Library is better, http, https etc.
https://developers.google.com/live/shows/474338138
very mini sample here:https://github.com/ogrebgr/android_volley_examples/blob/master/src/com/github/volley_examples/Act_SimpleRequest.java

Try Volley mate! I changed from AsyncTasks to Volley library and i am pretty pleased from the overall experience!
Volley Library

Connecting to PHP script through android app [duplicate]

This question already has answers here:
How can I fix 'android.os.NetworkOnMainThreadException'?
(66 answers)
Closed 9 years ago.
This is the code I have so far.
public void postData(String toPost) {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.mywebsite.com/dev/reverser.php");
//This is the data to send
String MyName = toPost; //any data to send
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("action", MyName));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
ResponseHandler<String> responseHandler = new BasicResponseHandler();
String response = httpclient.execute(httppost, responseHandler);
//This is the response from a php application
String reverseString = response;
Toast.makeText(this, "response" + reverseString, Toast.LENGTH_LONG).show();
} catch (ClientProtocolException e) {
Toast.makeText(this, "CPE response " + e.toString(), Toast.LENGTH_LONG).show();
// TODO Auto-generated catch block
} catch (IOException e) {
Toast.makeText(this, "IOE response " + e.toString(), Toast.LENGTH_LONG).show();
// TODO Auto-generated catch block
}
}//end postData()
Can somebody please tell me what is wrong in the following code! I have established that there is a problem in the try catch block only and not anywhere else in the activity. I just do not know what it is or how to correct it.
My PHP code is quite simple. It is something like this -
//code to reverse the string
$reversed = strrev($_POST["action"]);
echo $reversed;

In a comment above you indicated that you are getting a android.os.NetworkOnMainThreadException.
In the most recent versions of Android you are not allowed to do networking on the main thread as it makes the UI unresponsive. Move your code to a different thread using AsyncTask (see the Android developer guide for details) or some other mechanism.

Adding as a seperate answer as the poster requests to do so .
Assumption :
a ) There is a text box that accepts the URL to load
b ) A button which when clicked performs the networking operation on the URL fetched f
Implement a button click listener that calls the following function :
private void URL()
{
String url = txtURL.getText().toString();
new URLTask().execute(new String[] { url });
}
private class URLTask extends AsyncTask<String, Void, String>
{
protected String doInBackground(String... urls)
{
BufferedReader br = null;
String url = urls[0];
StringBuffer sb = new StringBuffer("");
try
{
HttpClient client = new DefaultHttpClient();
HttpPost request = new HttpPost();
request.setURI(new URI(url));
List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("param1", "value of param1"));
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters);
request.setEntity(formEntity);
HttpResponse response = client.execute(request);
String line;
br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
while ((line = br.readLine()) != null)
{
sb.append(line + "\n");
}
br.close();
}
catch(Exception e)
{
Toast.makeText(HttpPostActivity.this, "Exception: " + e.toString(), Toast.LENGTH_LONG).show();
}
finally
{
if (br != null)
{
try
{
br.close();
}
catch(IOException ioe)
{
ioe.printStackTrace();
}
}
}
return(sb.toString());
}
protected void onPostExecute(String result)
{
txtContent.setText(result);
}
You need to implement onPostExecute as well . There are other APIS .
Android Async Task Documentation

Try printing out the exception .
Use this code to print out your response . Check the status of the response
HttpResponse response = client.execute(request);
String line;
br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
while ((line = br.readLine()) != null)
{
sb.append(line + "\n");
}
br.close();
}
catch(Exception e)
{
Toast.makeText(HttpPostActivity.this, "Exception: " + e.toString(), Toast.LENGTH_LONG).show();
}
Tell us the exception . It would be easy to pinpoint your problems then .
EDIT : ANSWER :
You are trying to perform a networking operation on the MAIN thread . This is an illegal thing to do . Create a AsyncTask i.e create a seperate thread to do your networking operations .
Android Details of the exception
Stackoverflow question

startActivity() from inside onPostExecute() not working

I am doing an HttpPost to get data from a php server using async task. Basically the php script will either return a JSON array or null. It works fine when the json array is returned, however if the script returns null my if statement is not being picked up on and I am being returned this error:
Error parsing data org.json.JSONException: Value null of type org.json.JSONObject$1 cannot be converted to JSONArray
This is a snippet of my script:
#Override
protected Void doInBackground(String... params) {
String url_select = "http://localhost/test.php";
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url_select);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(3);
nameValuePairs.add(new BasicNameValuePair("id", id));
try {
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
//read content
is = httpEntity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection "+e.toString());
}
try {
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = "";
while((line=br.readLine())!=null){
sb.append(line+"\n");
}
is.close();
result=sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result "+e.toString());
}
return null;
}
protected void onPostExecute(Void v) {
if(result == "null"){
this.progressDialog.dismiss();
startActivity(new Intent(viewRandom.this, allDone.class));
}else{
try {
JSONArray Jarray = new JSONArray(result);
for(int i=0;i<Jarray.length();i++){
JSONObject Jasonobject = null;
Jasonobject = Jarray.getJSONObject(i);
String id = Jasonobject.getString("id");
}
this.progressDialog.dismiss();
} catch (Exception e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
}
}

Change if(result == "null") to if(result == null).
If you want to check for the string "null" do it with .equals(): if ("null".equals(result))
I am not sure if you really send a "null" string back from your server but anyway. As you might end returning null (not the string!), you should check for that, too.
Edit: Why is "null".equals(result) better than result.equals("null")? The answer is: the first one is null-safe which means it will not throw a NullPointerException when result is null. The second one will result in an exception in that case.

Instead of returning null Your Should try to return an Integer value to onPostExecute something like this
#Override
public Integer doInBackground(String...params){
.......
.......
return 1;
}
protected void onPostExecute(Integer v) {
if(v==1) {
}
}