Develop Reference

How to write / convert CURL for Android java

I am trying to implement the MOT history API https://dvsa.github.io/mot-history-api-documentation/ and they give an example using CURL which works with the supplied api key successfully when using an online CURL tool.
I am trying to implement this in Android and realise I have to use something like HttpPost rather than CURL, this is my code:
//Tried with full URL and by adding the registration as a header.
//HttpPost httpPost = new HttpPost("https://beta.check-mot.service.gov.uk/trade/vehicles/mot-tests?registration=" + reg_selected);
HttpPost httpPost = new HttpPost("https://beta.check-mot.service.gov.uk/trade/vehicles/mot-tests");
httpPost.addHeader("Content-Type", "application/json");
httpPost.addHeader("Accept", "application/json+v6");
httpPost.addHeader("x-api-key", "abcdefgh123456");
httpPost.addHeader("registration", reg_selected);
StringEntity entity = new StringEntity(jsonObj.toString(), HTTP.UTF_8);
httpPost.setEntity(entity);
HttpClient client = new DefaultHttpClient();
try {
HttpResponse response = client.execute(httpPost);
if (response.getStatusLine().getStatusCode() == 200) {
InputStream inputStream = response.getEntity().getContent();
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String readLine = bufferedReader.readLine();
String jsonStr = readLine;
JSONObject myJsonObj = new JSONObject(jsonStr);
}else if (response.getStatusLine().getStatusCode() == 400){
//Bad Request Invalid data in the request. Check your URL and parameters
error_text = "Bad Request";
}else if (response.getStatusLine().getStatusCode() == 403){
//Unauthorised – The x-api-key is missing or invalid in the header
error_text = "Authentication error"; //<<<< FAILS HERE 403
}
response.getStatusLine().getStatusCode() returns • "403 – Unauthorised – The x-api-key is missing or invalid in the header".
However the x-api-key that I use works correctly with the online CURL test so the actual key is correct but how I am adding it to my android code request must be invalid or similar.
Can anyone throw any light as to the correct way to convert the CURL into Android java so that the server does not return 403?
Thanks

It's easy to do with Jsoup:
// CREATE CONNECTION
Connection conn=Jsoup.connect("URL_GOES_HERE");
// ADD POST/FORM DATA
conn.data("KEY", "VALUE");
// ADD HEADERS HERE
conn.header("KEY", "VALUE");
// SET METHOD AS POST
conn.method(Connection.Method.POST);
// ACCEPT RESPONDING CONTENT TYPE
conn.ignoreContentType(true);
try
{
// GET RESPONSE
String response = conn.execute().body();
// USE RESPONSE HERE
// CREATE JSON OBJECT OR ANYTHING...
} catch(HttpStatusException e)
{
int status = e.getStatusCode();
// HANDLE HTTP ERROR HERE
} catch (IOException e)
{
// HANDLE IO ERRORS HERE
}
Ps: I guess you are confused with Header and Post Data. The key etc (Credentials) must be used as Post Data and Content Type etc as Header.

Post Request to WebService in Android

I have a problem with a WebService on Android. I am getting a 400 error but there is no information on the ErrorStream.
What I am trying to do is a POST request on a WCF Webservice using JSON.
I must add that I have includeExceptionDetailInFaults Enabled on my Service. The last time I got a 400 error, it was because I hadn't defined the RequestProperty. Now I don't get any error in the stream.
Here is the code:
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
// In my last error I had not included these lines. Maybe they are still wrong?
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Accept", "application/json");
urlConnection.setRequestMethod("POST");
urlConnection.setDoOutput(true);
urlConnection.setChunkedStreamingMode(0);
OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(out);
outputStreamWriter.write(jsonObject.toString(), 0, jsonObject.length());
outputStreamWriter.flush();
//outputStreamWriter.close();
int code = urlConnection.getResponseCode();
System.out.println(code);
if(code == 400) {
BufferedInputStream errorStream = new BufferedInputStream(urlConnection.getErrorStream());
InputStreamReader errorStreamReader = new InputStreamReader(errorStream);
BufferedReader bufferedReader = new BufferedReader(errorStreamReader);
StringBuilder builder = new StringBuilder();
String aux = "";
while ((aux = bufferedReader.readLine()) != null) {
builder.append(aux);
}
String output = builder.toString(); // The output is empty.
System.out.print(output);
}

Check Retrofit library from Square it's more easy and thin for GET/POST request and especially for REST. I suggest you to try it. It will make your life easy.
You can use different JSON parsers, error handlers, etc. Very flexible.
POST request definition using retrofit it's simple like this:
An object can be specified for use as an HTTP request body with the #Body annotation.
#POST("/users/new")
void createUser(#Body User user, Callback<User> cb);
Methods can also be declared to send form-encoded and multipart data.
Form-encoded data is sent when #FormUrlEncoded is present on the method. Each key-value pair is annotated with #Field containing the name and the object providing the value.
#FormUrlEncoded
#POST("/user/edit")
User updateUser(#Field("first_name") String first, #Field("last_name") String last);
After you define method inside your Java interface like shown above instantiate it:
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint("https://api.soundcloud.com")
.build();
MyInterface service = restAdapter.create(MyInterface.class);
And then you can call your method synchronously or asynchronously (in case you pass Callback instance).
service.myapi(requestBody);
See Retrofit documentation (http://square.github.io/retrofit/javadoc/index.html) and samples on GitHub for more details.

A 400 error might be occuring (and usually occurs in my case) because of incorrect URL or bad JSON format in post. please check those two
Using an HttpPost object will make your job a lot easier in my opinion
HttpPost post = new HttpPost(url);
if(payload != null){
try {
StringEntity entity = new StringEntity(payload,HTTP.UTF_8);
entity.setContentType(contentType);
post.setEntity(entity);
} catch (UnsupportedEncodingException e) {
LOG.d(TAG, "post err url : " + url);
LOG.e(TAG, "post err url" , e);
throw new Exception(1, e);
}
}
HttpResponse response=executeRequest(owner, post);

how to pass arguments to GET method in RESTfull webservice

I have to pass UserName and password as arguments into GET method for validation.after processing I need to get response.so how can I pass value into RESTful webservice GET method?

To pass parameters in HTTP GET you should use a ? delimiter. Such as
https://mywebsite.com/user/login?username=bob&password=123
https://mywebsite.com/user/login?paramname1=value1&paramname2=value2
Make sure to always use https with any sensitive data. You may also need to escape/encode both username and password to allow extended ASCII. If you need to support UNICODE you should consider using a POST request.

I think, you should use POST method if you want to do something with user name and password. because when you use GET method, the password would be visible on the URI,
https://samplesite.com/page/login?username=John&password=123
https://sampleste.com/page/login?name1=value1&name2=value2
Instead, you could use POST method to send user name and password values and in that case the URI would like below
https://samplesite.com/page/login
And the values will be sent as,
POST /page/login.asp HTTP/1.1
Host: samplesite.com
name1=value1&name2=value2
And you get below advantages on POST Method for secured transaction with server.
It never cached
Requests will remain in the browser history
Requests cannot be bookmarked
Requests have no restrictions on data length

You can do the following for Login validation,
// Create a new HttpClient and Post Header
String downloadedString= null;
HttpClient httpclient = new DefaultHttpClient();
//for registerhttps://te
HttpPost httppost = new HttpPost("YOUR LOGIN URL");
//add data
try{
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("username", UserName_Edit.getText().toString()));
nameValuePairs.add(new BasicNameValuePair("password", userPassword_Edit.getText().toString()));
//add data
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
InputStream in = response.getEntity().getContent();
StringBuilder stringbuilder = new StringBuilder();
BufferedReader bfrd = new BufferedReader(new InputStreamReader(in),1024);
String line;
while((line = bfrd.readLine()) != null)
stringbuilder.append(line);
downloadedString = stringbuilder.toString();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("downloadedString:in login:::"+downloadedString);
Use AsyncTask for your authentication and write the above method in the doInBackground().
EDIT
You can follow below tutorials also,
http://sarangasl.blogspot.in/2011/06/android-login-screen-using-httpclient.html
http://www.androidhive.info/2012/01/android-login-and-registration-with-php-mysql-and-sqlite/
Hope it helps.

Hi you can pass arguments to GET method in RESTfull like :
http://yoururl/<arg1>/<arg2>
eg.
http://yoururl/abc/123

Getting list of Facebook page status' updates in Android

How can I pull a list of all of a Facebook page's status updates in Android? This seems like such a simple question, but seems to be a very difficult task. I don't want to have to use the SDK. I thought it would be simple like twitter... http request and parse the resulting json. From research, the only way I seem to be able to get JSON out of Facebook is with their Open Graph, which requires registering an application, and generating access tokens. This seems like overkill just to try and get public status updates. Is there something I'm missing?
Im not trying to make any status updates, or get any other information. Im only wanting to read the public statuses off of a single Facebook page.

You have to Use Url like this
String url = "https://graph.facebook.com/" +facebook_User_name +"/statuses&limit=20&access_token=" + access_token
you have to pass that url to HttpGet method for getting information.
HttpGet httpget = new HttpGet(url);
HttpResponse response;
try {
response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
result= convertStreamToString(instream);
JSONObject json = new JSONObject(result);
JSONArray valArray = json.getJSONArray("data");
for(int i=0;i<valArray.length();i++) {
String info = main_object.getString("message");
}
instream.close();
}
}
catch (ClientProtocolException e) {
e.printStackTrace();
}

Please use this url to get the list of posts from facebook page
https://graph.facebook.com/"YOUR PAGE NAME"/feed?access_token="YOUR ACCESS TOKEN"
If you want to get your own facebook posts details use the beleow url
https://graph.facebook.com/me/feed?access_token="YOUR ACCESS TOKEN"

twitter streaming api - set filter in http post request (apache httpcomponents)

I'm trying out the twitter streaming api. I could succesfully filter tweets by using curl, as stated here:
curl -d #tracking http://stream.twitter.com/1/statuses/filter.json -u <user>:<pass>
where tracking is a plain file with the content:
track=Berlin
Now I tried to do the same thing in JavaSE, using Apache's HTTPComponents:
UsernamePasswordCredentials creds = new UsernamePasswordCredentials(<user>, <pass>);
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getCredentialsProvider().setCredentials(AuthScope.ANY, creds);
HttpPost httpPost = new HttpPost("http://stream.twitter.com/1/statuses/filter.json");
HttpParams params = new BasicHttpParams();
params = params.setParameter("track", "Berlin");
httpPost.setParams(params);
try {
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity entity = httpResponse.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
String t;
BufferedReader br = new BufferedReader(new InputStreamReader(instream));
while(true) {
t = br.readLine();
if(t != null) {
linkedQueue.offer(t);
}
}
}
} catch (IOException ioe) {
System.out.println(ioe.getMessage());
}
finally{
httpClient.getConnectionManager().shutdown();
}
When I run that, I get:
No filter parameters found. Expect at least one parameter: follow track
as a single entry in my linkedQueue. Seems the api wants the parameter in a different form, but cannot find any hint in the documentation. Can somebody share some experiences with the api or see any other problem with the code? Thanks!
EDIT
Putting the filter parameter into the params was a bad idea. As it's post data, it needs to be defined as an Entity before the request is being made:
StringEntity postEntity = new StringEntity("track=Berlin", "UTF-8");
postEntity.setContentType("application/x-www-form-urlencoded");
httpPost.setEntity(postEntity);
That's what I was doing wrong. Thanks Brian!

I suspect you need to post the data as the contents of your HTTP post. The man page for curl -d says:
(HTTP) Sends the specified data in a
POST request to the HTTP server, in
the same way that a browser does when
a user has filled in an HTML form and
presses the submit button. This will
cause curl to pass the data to the
server using the content-type
application/x-www-form-urlencoded.
so I believe you have to set that content type and put the contents of the tracking file in the body of your post.