Develop Reference

Java HTTP Request with Token Authentication

I am trying to make a GET request to a local server I have running. I am having trouble returning the correct data, I am seeing an 'Unauthorized' response. Can anyone spot any glaring issues with this given that the String 'token' is correct.
protected Object doInBackground(Void... params) {
try {
String url = "http://192.168.0.59:8000/events/";
URL object = new URL(url);
HttpURLConnection con = (HttpURLConnection) object.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestMethod("GET");
con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
con.setRequestProperty("Accept", "application/json");
con.setRequestProperty("Authorization:", "Token " + token);
//Display what the GET request returns
StringBuilder sb = new StringBuilder();
int HttpResult = con.getResponseCode();
if (HttpResult == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(
new InputStreamReader(con.getInputStream(), "utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
} else {
System.out.println(con.getResponseMessage());
}
} catch (Exception e) {
Log.d("Uh Oh","Check your network.");
return false;
}
return false;
}*
I was able to get a curl request working from the command line:
curl -H "Authorization: Token token" http://0.0.0.0:8000/events/

try this
con.setRequestProperty("Authorization", "Bearer " + token);

It turns out this issue was caused by including the con.setDoOutput(true); as get requests do not include a body.

HttpsURLConnection - Send POST request

I want to send a POST request to this particular API: https://developer.lufthansa.com/docs/read/api_basics/Getting_Started and I researched how to do that and tried everything but it simply doesn't work, I always get an HTTP 400 or an HTTP 401 error. Here's my code:
private void setAccessToken(String clientID, String clientSecret) {
try {
URL url = new URL(URL_BASE + "oauth/token");
String params = "client_id=" + clientID + "&client_secret=" + clientSecret + "&grant_type=client_credentials";
HttpsURLConnection connection = (HttpsURLConnection)url.openConnection();
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setDoOutput(true);
connection.connect();
OutputStreamWriter osw = new OutputStreamWriter(connection.getOutputStream());
osw.write(params);
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while((line = br.readLine()) != null) {
System.out.println(line);
}
} catch(IOException e) {
e.printStackTrace();
}
}
Kenta1561

Seems that your code is working well and it may be the case that you are providing invalid clientID or clientSecret so that your are getting wrong response in this case (as 401 indicates unauthorized). One thing you can do is you are only getting the response message if the http request status is ok (200). You may also get the invalid response message in case of 400 or 401 http response status. In order to print the invalid response messages you may follow the code below:
private void setAccessToken(String clientID, String clientSecret) throws Exception {
String params = "client_id=" + clientID + "&client_secret=" + clientSecret + "&grant_type=client_credentials";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
BufferedReader in;
// add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", "Mozilla/5.0");
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(params);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
if (responseCode >= 400)
in = new BufferedReader(new InputStreamReader(con.getErrorStream()));
else
in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println(response.toString());
}
In this way you can also get invalid response message. In your case when I tried to hit the provided api it is giving me the response below:
{"error": "invalid_client"}

Want to make perl code for oauth2 work in Java "curl -H 'Authorization: Bearer:<TOKEN> https://canvas.instructure.com/api/v1";

I am getting an error that I am unauthorized.. RESPONSE CODE 401
The token I am using works in perl..
This is what I have tried till now:
public static void main(String[] args) throws Exception {
try {
String auth = returnAuth(); //getting token from a file.
//System.out.println(auth);
String url1= "https://canvas.instructure.com/api/v1";
URL url = new URL(url1+"/courses");
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
connection.setRequestMethod("GET");
//connection.setRequestProperty("Authorization", "Bearer " + auth);
connection.setRequestProperty("Authorization", "Bearer "+auth);
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response code:" + connection.getResponseCode());
System.out.println("Response message:" + connection.getResponseMessage());
// Read the response:
BufferedReader reader = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
StringBuffer response = new StringBuffer();
while ((line = reader.readLine()) != null) {
response.append(line);
}
reader.close();
System.out.println(response.toString());
}
catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
}
}

public static void main(String[] args) throws Exception {
try {
String auth = returnAuth(); //getting token from a file.
String url1= "https://canvas.instructure.com/api/v1/courses";
URL url = new URL(url1);
HttpsURLConnection connection =(HttpsURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setRequestProperty("Authorization", "Bearer "+auth);
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response code:" + connection.getResponseCode());
System.out.println("Response message:" + connection.getResponseMessage());
// Read the response:
BufferedReader reader = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
reader.close();
}
catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
}
}

You have it commented out but every Oauth server I've dealt with would be "Bearer <token>" - one space and no colon.

You set the parameters AFTER you called!
Change your code to first set the authentication, then open the connection.
String url1= "https://canvas.instructure.com/api/v1";
URL url = new URL(url1+"/courses");
connection.setRequestProperty("Authorization", "Bearer "+auth);
connection.setRequestMethod("GET");
//now you can open the connection...
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();

java.io.IOException: Server returned HTTP response code: 411

I am trying to post to a server the following URL:
http://localhost:3000/webserver/query?q=AddData(123,2015)
Using the code below, the server is returning error 411.
HttpURLConnection connection = null;
try {
//Create connection
URL url = new URL(targetURL);
connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/xml");
connection.setRequestProperty("Authorization", "Basic " + Base64.encode("administrator:"));
connection.setRequestProperty("Content-Length", "0");
connection.setDoOutput(true);
//Get Response
InputStream is = connection.getInputStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
String line;
while((line = rd.readLine()) != null) {
System.out.println(line);
}
rd.close();
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if(connection != null) connection.disconnect();
}
I know that error 411 is an invalid Content-Length method. I have tried giving the Content-Length the length of the URL but the error persisted.
Can you please help with this issue?

Can't get Set-Cookie property in Java

I have a java method which should get Set-Cookie property for following login into webpage. But the conn.getHeaderFields().get("Set-Cookie") does not return anything. Any advice?
private String GetPageContent(String url) throws Exception {
URL obj = new URL(url);
conn = (HttpsURLConnection) obj.openConnection();
// default is GET
conn.setRequestMethod("GET");
conn.setUseCaches(false);
// act like a browser
conn.setRequestProperty("User-Agent", USER_AGENT);
conn.setRequestProperty("Accept",
"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
conn.setRequestProperty("Accept-Language", "s-CZ,cs;q=0.8,en;q=0.6");
if (cookies != null) {
for (String cookie : this.cookies) {
conn.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
}
}
int responseCode = conn.getResponseCode();
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " + responseCode);
BufferedReader in =
new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
// Get the response cookies
System.out.println(conn.getHeaderFields().get("Set-Cookie")); //print for testing
setCookies(conn.getHeaderFields().get("Set-Cookie"));
return response.toString();
Whole program: http://pastebin.com/3nB682L7
Anyone?..:-)

Recent Java versions have "fixed" URLConnection to hide cookies that are marked HttpOnly, and I don't think there's a setting to disable that. I would recommend using HttpClient from Apache HttpComponents.