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MailChimp Integration in Java

I want to integrate MailChimp API in my java project. When I call Rest call using HttpURLConnection class, it responds with 401 code.
Here is my code:
URL url = new URL("https://us13.api.mailchimp.com/3.0/lists");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Authorization", "apikey <my-key>");
String input = "<json data>";
OutputStream os = conn.getOutputStream();
//os.write(input.getBytes());
os.flush();
if (conn.getResponseCode() != HttpURLConnection.HTTP_CREATED) {
throw new RuntimeException("Failed : HTTP error code : " + conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println(output);
}
conn.disconnect();

I will suggest using Apache Commons Codec package for encoding.
It support various formats such as Base64 and Hexadecimal.
Earlier I was also facing the same issue. I am sharing the code that I used in my application for authenticating to Mailchimp API v-3.0
//basic imports
import org.apache.commons.codec.binary.Base64;
.
.
.
//URL to access and Mailchimp API key
String url = "https://us9.api.mailchimp.com/3.0/lists/";
//mailchimp API key
String apikey = xxxxxxxxxxxxxxxxxxxxxxxxxxx
// Authentication PART
String name = "Anything over here!";
String password = apikey; //Mailchimp API key
String authString = name + ":" + password;
byte[] authEncBytes = Base64.encodeBase64(authString.getBytes());
String authStringEnc = new String(authEncBytes);
URL urlConnector = new URL(url);
HttpURLConnection httpConnection = (HttpURLConnection) urlConnector.openConnection();
httpConnection.setRequestMethod("GET");
httpConnection.setDoOutput(true);
httpConnection.setDoInput(true);
httpConnection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
httpConnection.setRequestProperty("Accept", "application/json");
httpConnection.setRequestProperty("Authorization", "Basic " + authStringEnc);
InputStream is1 = httpConnection.getInputStream();
StringBuilder sb = new StringBuilder();
BufferedReader br = new BufferedReader(new InputStreamReader(is1, "utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
Now you can use StringBuilder Object sb to parse the output as required
Hope it resolves your issue :)

HTTP 401 response code means "not authorized".
You didn't set or pass your credentials properly. Is the certificate from the client set up? Here's an example of an HTTPS client.

HTTP 401 simply means you're not Authorized to send this request.
you can set username any string (the MailChimp docs suggest using anystring as a username) and your API key as a password.
In case of Postman request, you can set under the Authorization tab choose Basic Auth to set username and password. Below image shows the same.
More info about Adding/ Getting Members to/ from a Mailing List on MailChimp API 3.0, I find this article very useful.

Java HTTP post assistance

I've been working with the Slack API in java and have been trying to get an HTTP method that can be used like my below example block of code. That code block works, but the issue is I need to also include a 200 response code, and can't figure out how to get it to work.
Basically, how can I, In Java, send an HTTP post and also tag on the 200 status code using the URL and the content?
Current code:
public void httpRequest(URL url, String content) {
try {
byte[] contentBytes = content.getBytes("UTF-8");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setRequestProperty("Accept-Charset", "UTF-8");
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Content-Length", Integer.toString(contentBytes.length));
connection.setRequestProperty("Status", Integer.toString(200));
OutputStream requestStream = connection.getOutputStream();
requestStream.write(contentBytes, 0, contentBytes.length);
requestStream.close();
String response = "";
BufferedReader responseStream;
response = "" + ((HttpURLConnection) connection).getResponseCode();
try {
if (((HttpURLConnection) connection).getResponseCode() == 200) {
responseStream = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
} else {
responseStream = new BufferedReader(new InputStreamReader(((HttpURLConnection) connection).getErrorStream(), "UTF-8"));
}
response = responseStream.readLine();
responseStream.close();
} catch (NullPointerException ignored) {
}
} catch (IOException e) {
e.printStackTrace();
}
}

The call to setDoOutput(true) triggers a post, i.e. you do not need to add
connection.setRequestMethod("POST");
Adding a status header to the request is possible, as you have done, but typically one associates status codes with http responses, not requests. - And off course, adding such custom header would only make sense if the server was designed to use this information to anything.
See this big, and highly up-voted answer on java.net.HttpURLConnection.
Also, you have some problems relating to your response variable as well as the BufferedReader. You accidentally override the value you initially assigned to the response field, instead of concatening. Also, your readLine() should probably be in a loop:
String tmp;
while ((tmp = responseStream.readLine()) !=null){
response += tmp;
}

Android: not getting xml out of http get request with basic authentication

My goal is to get the xml from an API. The API uri I use, including parameters is http://webservices.ns.nl/ns-api-treinplanner?fromStation=Roosendaal&toStation=Eindhoven. I am given a username and password, for what I think probably is basic authorization.
I tried various things like something with an Authenticator, the format http://username:password#webservices.ns.nl/ns-api-treinplanner, but at the end of a lot of SO searching I ended up with something with a setRequestProperty with the basic authorization.
I put the code into an AsyncTask which seems to work correctly so I will just put the code from inside doInBackground in here.
As the java FileNotFoundException I first got didn't give me much information, I found out how to use the getErrorStream to find out more.
InputStream in;
int resCode;
try {
URL url = new URL("http://webservices.ns.nl/ns-api-treinplanner?fromStation=Roosendaal&toStation=Eindhoven");
String userCredentials = "username:password";
String encoding = new String(android.util.Base64.encode(userCredentials.getBytes(), Base64.DEFAULT));
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestProperty("Authorization", "Basic " + encoding);
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
try {
resCode = urlConnection.getResponseCode();
if (resCode == HttpURLConnection.HTTP_OK) {
Log.i("rescode","ok");
in = urlConnection.getInputStream();
} else {
Log.i("rescode","not ok");
in = urlConnection.getErrorStream();
}
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(in));
StringBuilder stringBuilder = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
bufferedReader.close();
return stringBuilder.toString();
}
finally{
urlConnection.disconnect();
}
}
catch(Exception e) {
Log.e("ERROR", e.getMessage(), e);
return null;
}
Then, in onPostExecute I print the response, but the response I get is
<?xml version="1.0"?>
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" soap:encodingStyle="http://www.w3.org/2003/05/soap-encoding">
<soap:Header></soap:Header>
<soap:Body><soap:Fault>
<faultcode>soap:Server</faultcode>
<faultstring>006:No customer found for the specified username and password</faultstring></soap:Fault>
</soap:Body></soap:Envelope>
This is of course not right, it should give a full xml of in this case a train voyage recommendation.
I tested with my browsers, and also using a HTTP request tool called Postman which returned the correct xml so all the uri's, parameters, username and password are correct.

The encoding used is wrong. The base64 encoding used randomly returns whitespaces in the middle, adding encoding = encoding.replaceAll("\\s+",""); actually fixed it.

Sending UTF-8 string using HttpURLConnection

till now I've used the following code snippet in order to send and recieve JSON strings:
static private String sendJson(String json,String url){
HttpClient httpClient = new DefaultHttpClient();
String responseString = "";
try {
HttpPost request = new HttpPost(url);
StringEntity params =new StringEntity(json, "UTF-8");
request.addHeader("content-type", "application/json");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
HttpEntity entity = response.getEntity();
responseString = EntityUtils.toString(entity, "UTF-8");
}catch (Exception ex) {
ex.printStackTrace();
// handle exception here
} finally {
httpClient.getConnectionManager().shutdown();
}
return responseString;
}
The code above worked perfect even if the json string contained UTF-8 chars, and everything worked fine.
For several reasons I had to change the way I send HTTP post requests and use HttpURLConnection instead apache's HttpClient. Here's my code:
static private String sendJson(String json,String url){
String responseString = "";
try {
URL m_url = new URL(url);
HttpURLConnection conn = (HttpURLConnection)m_url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("content-type", "application/json");
DataOutputStream outputStream = new DataOutputStream(conn.getOutputStream());
outputStream.writeBytes(json);
outputStream.flush();
outputStream.close();
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
sb.append(line+"\n");
}
br.close();
responseString = sb.toString();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return responseString;
}
This code works well for normal English characters, but doesn't seem to support UTF-8 characters in the json string, since it fails each time. (when sending json to server, server crushes saying that utf8 cant decode a certain byte, but when recieving utf8 json from server I think it does work since I manage to view the special characters).
Server didn't change at all and worked fine with previous code, so the problem is 100% on this new code snippet.
Any idea how to fix the json string sending so it would support UTF 8? Thanks

I think the problem is in this part:
DataOutputStream outputStream = new DataOutputStream(conn.getOutputStream());
outputStream.writeBytes(json);
outputStream.flush();
outputStream.close();
Instead of doing this you need to encode json as UTF-8
and send those bytes which represent the UTF-8 encoding.
Try using this:
Charset.forName("UTF-8").encode(json)
See:
Charset.encode
An even simpler approach is to use e.g. a BufferedWriter wrapping an
OutputStreamWriter. The OutputStreamWriter knows about its own encoding
and so it will do the work for you (the encoding work of the json String).
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream(), "UTF-8"));
bw.write(json);
bw.flush();
bw.close();

When writing a String to an output stream (bytes), you need to specify the encoding to do the conversion.
One way to do is to wrap the output stream in a OutputStreamWriter that will use UTF-8 charset for the encoding.
conn.setRequestProperty("content-type", "application/json; charset=utf-8");
Writer writer = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream(), "UTF-8"));
writer.write(json);
writer.close();
The flush() is also optional if you call close().
Another option, as mentionned by peter.petrov is to first convert your String to bytes (in memory) and then output the byte array to your output stream.
And to make it obvious on the server side, you can pass the charset used in the content-type header ("content-type", "application/json; charset=utf-8").

StringEntity uses a Charset to make sure the encoding is right. It does ~that:
byte[] content = s.getBytes(charset);
Without much change in your code, your write can be:
outputStream.write(json.getBytes("UTF-8"));
As for your read, there is no point in using a BufferedReader with readLine, except for normalizing the end of line. It is much slower than other methods, as it requires to read each byte individually.
EntityUtils does mostly that:
Reader reader = new InputStreamReader(conn.getInputStream(), "UTF-8");
StringBuilder buffer = new StringBuilder();
char[] tmp = new char[1024];
int l;
while((l = reader.read(tmp)) != -1) {
buffer.append(tmp, 0, l);
}
responseString = buffer.toString();

Send HTTP Post Payload with Java

I'm trying to connect to the grooveshark API, this is the http request
POST URL
http://api.grooveshark.com/ws3.php?sig=f699614eba23b4b528cb830305a9fc77
POST payload
{"method":'addUserFavoriteSong",'parameters":{"songID":30547543},"header":
{"wsKey":'key","sessionID":'df8fec35811a6b240808563d9f72fa2'}}
My question is how can I send this request via Java?

Basically, you can do it with the standard Java API. Check out URL, URLConnection, and maybe HttpURLConnection. They are in package java.net.
As to the API specific signature, try sStringToHMACMD5 found in here.
And remember to CHANGE YOUR API KEY, this is very IMPORTANT, since everyone knows it know.
String payload = "{\"method\": \"addUserFavoriteSong\", ....}";
String key = ""; // Your api key.
String sig = sStringToHMACMD5(payload, key);
URL url = new URL("http://api.grooveshark.com/ws3.php?sig=" + sig);
URLConnection connection = url.openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
connection.connect();
OutputStream os = connection.getOutputStream();
PrintWriter pw = new PrintWriter(new OutputStreamWriter(os));
pw.write(payload);
pw.close();
InputStream is = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line = null;
StringBuffer sb = new StringBuffer();
while ((line = reader.readLine()) != null) {
sb.append(line);
}
is.close();
String response = sb.toString();

You could look into the Commons HttpClient package.
It is fairly straight forward to create POST's, specifically you could copy the code found here: http://hc.apache.org/httpclient-3.x/methods/post.html:
PostMethod post = new PostMethod( "http://api.grooveshark.com/ws3.php?sig=f699614eba23b4b528cb830305a9fc77" );
NameValuePair[] data = {
new NameValuePair( "method", "addUserFavoriteSong..." ),
...
};
post.setRequestBody(data);
InputStream in = post.getResponseBodyAsStream();
...
Cheers,