Develop Reference

Can I send a Android HttpGet (not HttpPost) with 1 string param?

Im coding a RESTful API & Android client at the same time as I go and im currently working on pulling the users profile from the server. I feel like this should definitely be a get request being that im only pulling existing data and im not adding/editing anything to my database, but I do need a user_id param to be able to query for the appropriate profile. Can I send just one tiny little variable along with my HttpGet some how or am i supposed to use a HttpPost in this situation regardless?

Android uses Apache's HTTPClient. So, copying their tutorial code:
public void sendStringTo(String remoteUrl, String myString) {
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(remoteUrl+"?string1="+myString);
HttpResponse response1 = httpclient.execute(httpGet);
// The underlying HTTP connection is still held by the response object
// to allow the response content to be streamed directly from the network socket.
// In order to ensure correct deallocation of system resources
// the user MUST either fully consume the response content or abort request
// execution by calling HttpGet#releaseConnection().
try {
System.out.println(response1.getStatusLine());
HttpEntity entity1 = response1.getEntity();
// do something useful with the response body
// and ensure it is fully consumed
EntityUtils.consume(entity1);
} finally {
httpGet.releaseConnection();
}
return;
}

GET can support adding variables/parameters. For example you could make a Url that looks like this:
http://yourwebsite.com/script.php?user_id=19898424

Http Put Request

I am using the HttpPut to communicate with server in Android, the response code I am getting is 500.After talking with the server guy he said prepare the string like below and send.
{"key":"value","key":"value"}
now I am completely confused that where should i add this string in my request.
Please help me out .

I recently had to figure out a way to get my android app to communicate with a WCF service and update a particular record. At first this was really giving me a hard time figuring it out, mainly due to me not knowing enough about HTTP protocols, but I was able to create a PUT by using the following:
URL url = new URL("http://(...your service...).svc/(...your table name...)(...ID of record trying to update...)");
//--This code works for updating a record from the feed--
HttpPut httpPut = new HttpPut(url.toString());
JSONStringer json = new JSONStringer()
.object()
.key("your tables column name...").value("...updated value...")
.endObject();
StringEntity entity = new StringEntity(json.toString());
entity.setContentType("application/json;charset=UTF-8");//text/plain;charset=UTF-8
entity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,"application/json;charset=UTF-8"));
httpPut.setEntity(entity);
// Send request to WCF service
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(httpPut);
HttpEntity entity1 = response.getEntity();
if(entity1 != null&&(response.getStatusLine().getStatusCode()==201||response.getStatusLine().getStatusCode()==200))
{
//--just so that you can view the response, this is optional--
int sc = response.getStatusLine().getStatusCode();
String sl = response.getStatusLine().getReasonPhrase();
}
else
{
int sc = response.getStatusLine().getStatusCode();
String sl = response.getStatusLine().getReasonPhrase();
}
With this being said there is an easier option by using a library that will generate the update methods for you to allow for you to update a record without having to manually write the code like I did above. The 2 libraries that seem to be common are odata4j and restlet. Although I haven't been able to find a clear easy tutorial for odata4j there is one for restlet that is really nice: http://weblogs.asp.net/uruit/archive/2011/09/13/accessing-odata-from-android-using-restlet.aspx?CommentPosted=true#commentmessage

Error 500 is Internal Server error. Not sure if this answers your question but I personally encountered it when trying to send a data URI for an animated gif in a PUT request formatted in JSON but the data URI was too long. You may be sending too much information at once.

Programmatically filling in a website form using MultipartEntity

I'm taking a mobile development class, which focuses on Android, and for my term project I thought it would be cool if I made a little application that returns a list of cancer-related events and fundraisers. Basically what I have to do is programmatically fill in a webform given criteria that is input from my application, and parse the returned results to give a list of events, because for some reason the American Cancer Society doesn't keep a public list of all events. This is my first real experience with android, and I have almost zero experience with network programming. If I really wanted to, I could just change the URL I go to based on the paramaters given to me, because the ACS event search URLs all look almost exactly the same, but I want to do it "right". I looked at this post and this one for guidance, which led me to the MultipartEntity. They've been very helpful, but I really am not sure what to do next. Code is below:
//Base case, creates entity based on Entered ZIP Code
public void sendRequest()
{
EditText MyEditText = (EditText)findViewById(R.id.zip_edit_text);
String ZIP = MyEditText.getText().toString();
HttpClient defaultClient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.cancer.org/Involved/Participate/app/event-search");
try{
MultipartEntity entity = new MultipartEntity();
entity.addPart("ZIP",new StringBody(ZIP));
httppost.setEntity(entity);
HttpResponse response = defaultClient.execute(httppost);
HttpEntity result = response.getEntity();
InputStream stream = result.getContent();
String s = new Scanner(stream).useDelimiter("\\A").next();
Intent intent = new Intent(HomeScreen.this, ListResults.class);
startActivity(intent);
AlertDialog dialog = new AlertDialog.Builder(this).create();
dialog.setMessage(s);
dialog.show();
}catch (ClientProtocolException e){
e.printStackTrace();
} catch (IOException e){
e.printStackTrace();
}
}
It's pretty bare-bones right now, as you can see. The AlertDialog is used just to see what the HttpResponse looks like, and it seems like it does the POST correctly, and the ZIP code ends up in the right text field, but it doesn't actually "click" the search button. Personally, I think either:
1.) My HttpPost object's URL was incorrect
2.) I used POST instead of GET, or i should POST then GET
I really have tried to work this out myself, and have searched StackOverflow, but I've really come to a rough patch, and as I said before, my network programming experience is near nonexistent. Any help would be appreciated.

I would suggest that you do a printout the URL that was sent through your multipart method, do a search via the web browser, and see if both URL matches. If the URL doesn't match, it means that there's something wrong while setting your entity, etc.

HttpPost: No "Set-Cookie" Header

I want to get the session cookie of a website. Unfortunately the "Set-Cookie"-Header doesn't show up.
Here's the code I've written:
"commands" is a String[][] and the whole code is wrapped by try/catch.
CookieStore cookieStore = new BasicCookieStore();
HttpContext localContext = new BasicHttpContext();
localContext.setAttribute(ClientContext.COOKIE_STORE,cookieStore);
HttpPost httppost = new HttpPost(url);
List<NameValuePair> nvps = new ArrayList<NameValuePair>(0);
for (int i=0;i<commands.length;++i)
nvps.add(new BasicNameValuePair(commands[i][0],commands[i][1]));
httppost.setEntity(new UrlEncodedFormEntity(nvps,HTTP.UTF_8));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
Header[] headers = response.getAllHeaders();
List<Cookie> cookies = cookieStore.getCookies();
String data = EntityUtils.toString(entity);
My understanding of Http Communication tells me that there should be a "Set-Cookie" Header. The only Headers I get from response.getAllHeaders() are Connection:close, X-Powered-By:PHP/4.3.4 and Content-Type:text/html
There is a bit of javascript included in the returned data (response.getEntity()).
<script language = "javascript">
<!--
location.href="/index.php";
function SetCookie(name,value,expire,path){
document.cookie = name + "=" + escape(value) + ((path == null) ? "":(";path="+path))
}
var iad = 461180104
SetCookie("iad",iad,0,"/")
-->
</script>
As far as I understand this, this code is never executed because it's just a comment ?!
But as well this is probably the bit where the cookie should be created.
Any ideas?
UPDATE:
"Opera Mobile" is the only browser for Android I found which has no problem with cookies on this site. "Opera Mini", "Dolphin HD" and the Froyo Stock browser all fail. No Desktop browser has problems connecting. Is this a webkit issue? And if this is the case: how to avoid it?

Using Chrome's developer tools or Firebug, check the HTTP response for the "expires" parameter in the Set-Cookie header field. Make sure the time / date settings on the phone are set correctly. If the browser thinks the cookie is already expired, it won't store it.
If that doesn't work try using wireshark / tshark to grab a trace of the communication from your client, and compare it to a browser that's working the way you expect it to.
By the way, the comment delimiters around that bit of Javascript don't prevent the script from being run; they just prevent older (really old) browsers from trying to render the script in the document. That cookie ("iab") doesn't look like the cookie for authentication. There's likely an http-only cookie with a session identifier; you should be able to see it using the aforementioned Firebug / Dev tools.

Android HTTP login questions

I am implementing a login feature in Android.
Does android have anything like sessions or cookies? How should I 'remember' that the user is loged in? Obviously I don't want to ask for the password every time my application is used!
Should I hash the password before sending it to the server? I have a table in my database with a user and password column. When I want to check the login, should I send the password hashed to the server like login.php?u=sled&p=34819d7beeabb9260a5c854bc85b3e44, or just plain text like login.php?u=sled&p=mypassword and hash it on the server before I perform the authentication?

Does android have anything like sessions or cookies?
Yes. There are two alternatives.
Option #1:
You can use CookieManager to set your cookie.
Option #2:
The other alternative (I'm using this alternative in one of my applications) is to grab your cookie after you've sent your username and password to the server (e.g. via HttpPost or HttpGet). In your question you're using $_GET style of your login authentication, so my sample code will be using HttpGet.
Sample code using HttpGet:
HttpParams httpParams = new BasicHttpParams();
// It's always good to set how long they should try to connect. In this
// this example, five seconds.
HttpConnectionParams.setConnectionTimeout(httpParams, 5000);
HttpConnectionParams.setSoTimeout(httpParams, 5000);
DefaultHttpClient postClient = new DefaultHttpClient(httpParams);
// Your url using $_GET style.
final String url = "www.yourwebsite.com/login.php?u=myusername&p=mypassword";
HttpGet httpGet = new HttpGet(url);
HttpResponse response;
try {
// Execute your HttpGet against the server and catch the response to our
// HttpResponse.
response = postClient.execute(httpGet);
// Check if everything went well.
if(response.getStatusLine().getStatusCode() == 200) {
// If so, grab the entity.
HttpEntity entity = response.getEntity();
// If entity isn't null, grab the CookieStore from the response.
if (entity != null) {
CookieStore cookies = postClient.getCookieStore();
// Do some more stuff, this should probably be a method where you're
// returning the CookieStore.
}
}
} catch (Exception e) {
}
Now when you have your CookieStore; grab a list of cookies from it and after that you can use Cookie to determine the name, domain, value etc...
Next time you're trying to access "locked" content of your website; set a cookie to your HttpURLConnection from your Cookie information:
URL url = new URL("www.yourwebsite.com/lockedcontent.php");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setInstanceFollowRedirects(false);
// "Host" and "Cookie" are fields in the HTTP response. Use WireShark
// via your computer to determine correct header names.
httpURLConnection.setRequestProperty("Host", domainOfYourCookie);
httpURLConnection.setRequestProperty("Cookie", valueOfYourCookie);
final int responseCode = httpURLConnection.getResponseCode();
// And get the content...
Should I hash the password before sending it to the server?
Depends on how your system is designed. You must have correct information when sending it to your server. This also depends on how you're hashing your information in your .php file.
How should I 'remember' that the user is loged in?
Store the information in a SharedPreferences or something. Like I said earlier, you can hash it if your login system is correctly designed - this depends on how you're hashing it in your .php file.