Web Service using HTTP Protocol in Android - android

can anyone give me an idea of using web service using HTTP protocol.

Here is an example for "Executing a HTTP POST Request with HttpClient":
public void postData() {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/script.php");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", "123"));
nameValuePairs.add(new BasicNameValuePair("username", "Paresh"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
}

We can use web services in our application to send and receive data from a remote server. Consider the case of an login section from a application where you need to pass username and password to the server for checking the whether the user is a valid user or not. In this case the username and password are attached with a url and send it to the remote server for validation and in response you get a value stating whether the user is a valid user or not. Usually the response will be either in XML format or JSON format from there we need to parse that response to get the necessary values. Check out the following example code in this I have created a class named "parsing" and it using the http protocol to receive a data.
public class parsing extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
HttpClient client = new DefaultHttpClient();
String postURL = "http://services.digg.com/topics?appkey=http://example.com&type=json";
HttpPost post = new HttpPost(postURL);
HttpResponse responsePOST = client.execute(post);
HttpEntity resEntity = responsePOST.getEntity();
String response=EntityUtils.toString(resEntity);
response=response.trim();
Log.i("RESPONSE=",response);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
See the response on the Logcat and do not for get to include <uses-permission android:name="android.permission.INTERNET" />
because we are fetching the data from the remote server which needs internet permission.

Related

Android sends GET instead of POST

I have a backend for my android app, which returns 404 on GET and json on POST. Now, I'm trying to do POST request using this snippet:
public void postData() {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/api/login");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("email", "email#email.com"));
nameValuePairs.add(new BasicNameValuePair("password", "qwerty"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
}
Server however receives GET request. With curl POST backend returns json as expected. But somehow httpPost sends GET(!) request. What could be the problem? What am I doing wrong?
Ok guys, answered my own question pretty quickly, may be helpful for others.
I replaced hostname with ip address, and it worked!

Android:How to retrieve data from phpliteadmin to android application..?

I have connected database with phpliteadmin using xampp on localhost. Now I have to retrieve data from localhost and also to update it.. So any 1 can help me out from this problem..??
ok i have a function that sends some data to your local host and retrieve some data from there
use this method for communication :-
public void postData() throws Exception {
postData=et.getText().toString(); //some value
HttpClient httpclient = new DefaultHttpClient(); // connection
HttpPost httppost = new HttpPost("http://192.168.1.21/default.php"); //ip of your local host and php file!
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("msg", ""+str));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8));
ResponseHandler<String> responseHandler=new BasicResponseHandler(); // to get the response printed there
String responseBody = httpclient.execute(httppost, responseHandler); // here we are recieving values.
Toast.makeText(this, responseBody, Toast.LENGTH_LONG).show();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
}
}
and you can use this php coding to send and retrieve values :-
<?php
include ('MCrypt.php'); //this my encryption example
$thename=$_POST["msg"]; //get values from there using post and "msg" must be same on both side!
$mcrypt = new MCrypt();
$decrypted = $mcrypt->decrypt($thename);
echo("Your Encrypted String:--".$thename."\n"); // this line will be sent to android and will be recived in String Response;
echo("Your Decrypted String:--".$decrypted);
?>

android httpClient and httpPost issue with specific website

I am attempting to help a student write an android app that will contact a specific webserver. From the looks of the website, you can issue a GET requestion with your web browser and you get back a cookie session and an "authenticity token" (see the source of the page as an invisible input)
We issue a GET request and then want to follow it up with the post, but we are receiving a status code of 404 on the post. On a side note, the first GET request returns a code of 200.
Does anyone have any ideas? Below is the code that gets executed...
public void run()
{
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("https://co22.herokuapp.com/login/");
HttpPost httpPost = new HttpPost("https://co22.herokuapp.com/login/sessions");
HttpResponse response;
try
{
response = httpClient.execute(httpGet);
Log.d("matt",response.getStatusLine().toString());
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("session[network_id]", username));
nameValuePairs.add(new BasicNameValuePair("session[password]", password));
nameValuePairs.add(new BasicNameValuePair("authenticity_token","9yvxPOUpRFdsTeHAZtISEfBHpElDTHzvMjAbQnxOHDM="));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
response = httpClient.execute(httpPost);
Log.d("matt",response.getStatusLine().toString());
}
catch (ClientProtocolException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
It appears that the above will work correctly, but we were just sending the second post request to the wrong website.

HTTP Post OK, how to display the response?

I'm trying to increase my knowledge to Android and trying to code a small app for my personal needs.
I'm trying to post data via the HTTP Post method on a test server.
The request is sent ok, but now, I'm trying to display the response, which is an HTML page with the dump of my request.
Here is an extract of my code, it is basically a few EditText fields, and button that sends the request.
The following code is the listener for that button.
validateButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://posttestserver.com/post.php?dump&html&dir=mydir&status_code=200");
try {
// Gathering data
String value01 = nb01Spinner.getSelectedItem().toString();
String value02 = nb02EditText.getText().toString();
String value03 = nb03EditText.getText().toString();
String value04 = nb04EditText.getText().toString();
// Add data to value pairs
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(04);
nameValuePairs.add(new BasicNameValuePair("test01", value01));
nameValuePairs.add(new BasicNameValuePair("test02", value02)); //
nameValuePairs.add(new BasicNameValuePair("test03", value03));
nameValuePairs.add(new BasicNameValuePair("test04", value04));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
I'm not sure if I need to create another Activity or not... I suppose I also have to create a webview aswell, but I'm a bit lost. For now the "raw" HTML would be fine, but afterwards I will need to parse the data, and extract only the strings I need.
So I would need help (an a good and simple example !)
Thank you.
String ret = EntityUtils.toString(response.getEntity());
Maybe this will help?
Very simple approach is Take textview the way you have taken button widget. and what ever response you got set in the textview. you will be able to see the response. else use the Log to log your response in the logcat.
This is how you get the Http response :
byte[] buffer = new byte[1024];
httpclient = new DefaultHttpClient();
httppost = new HttpPost("http://www.rpc.booom.com");
postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("params","1"));
//.......
httppost.setEntity(new UrlEncodedFormEntity(postParameters));
HttpResponse response = httpclient.execute(httppost);
Log.w("Response ","Status line : "+ response.getStatusLine().toString());
buffer = EntityUtils.toString(response.getEntity()).getBytes();
I am using:
Log.d("log_response", response.getStatusLine().toString());

403 FORBIDDEN message when I use HttpPost to send data to Django

I am trying to send data from android to Django app. I want to store the data in a table in sqlite database called "mytable". Here is the android code:
try {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://localhost:8000/androidweb/edit/");
JSONObject j = new JSONObject();
try {
j.put("name", "david");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
nameValuePairs.add(new BasicNameValuePair("year", j.toString()));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// myTextView.setText(j.toString());
HttpResponse response = httpclient.execute(httppost);
myTextView.setText(response.getStatusLine().toString());
// myTextView.setText(response.toString());
}catch(Exception e) {
myTextView.setText("Error in http connection "+e.toString());
}
The issue is resolved now. I only needed to have a return value
Sounds like Django's Cross-Site Request Forgery framework, which by default prevents third-party POST requests. Read Django's CSRF docs for details.

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