Develop Reference

JAVA rest assure get request with auth token

I am trying to create a post request with auth token but I am getting null response. Can you please help me.Can you please let me know what am I missing in the code ?
public static void main(String[] args) {
try {
String url = "https://test.abc.com/";
String token="XXXXXX-abcd-496a-ae73-7659587896";
URL object = new URL(url);
HttpURLConnection con = (HttpURLConnection) object.openConnection();
con.setDoInput(true);
con.setRequestMethod("GET");
con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
con.setRequestProperty("Accept", "application/json");
con.setRequestProperty("Authorization", "Bearer " + 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();
System.out.println(con.getResponseMessage());
} else {
System.out.println(con.getResponseMessage());
}
} catch (Exception e) {
System.out.println(e);
}
}
}

Connection refused Android Api

Good afternoon. I am trying to connect Android app to http://localhost:3000/ ( but in code I use an emulator's ip).
The error is "W/System.err: java.net.ConnectException: Connection refused"
Could you help me to find an error? Other posts were not useful for me.
public String execute() {
String line;
StringBuilder outputStringBuilder = new StringBuilder();
try {
StringBuilder urlString = new StringBuilder(baseUrl + urlResource);
if (!urlPath.equals("")) {
urlString.append("/" + urlPath); }
if (parameters.size() > 0 && httpMethod.equals("POST")) {
payload = getPayloadAsString();
urlString.append("?" + payload); }
URL url = new URL(urlString.toString());
String encoding = Base64Encoder.encode(email + ":" + password);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod(httpMethod);
connection.setRequestProperty("Authorization", "Basic " + encoding);
connection.setRequestProperty("Accept", "application/json");
connection.setRequestProperty("Content-Type", "text/plain");
connection.connect();
if (httpMethod.equals("GET") || httpMethod.equals("PUT")) {
payload = getPayloadAsString();
connection.setDoInput(true);
connection.setDoOutput(true);
try {
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
writer.write(payload);
headerFields = connection.getHeaderFields();
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((line = br.readLine()) != null) {
outputStringBuilder.append(line);
}
} catch (Exception ex) {}
connection.disconnect();
}
else {
InputStream content = (InputStream) connection.getInputStream();
headerFields = connection.getHeaderFields();
BufferedReader in = new BufferedReader(new InputStreamReader(content));
while ((line = in.readLine()) != null) {
outputStringBuilder.append(line);} }
} catch (Exception e) {
e.printStackTrace(); }
if (!outputStringBuilder.toString().equals("")) {
lastResponse = outputStringBuilder.toString(); }
return outputStringBuilder.toString(); }}

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();

Retrieve data with HttpUrlConnection even with bad http codes 403. 404, etc

I have the following method that works fine, but it throws an exception when the server returns 403 code which results in the method to never return the server response.
public String ping(String lat, String lon)
{
StringBuffer response = null;
try
{
String url = "https://api.mysite.com";
URL urlObj = new URL(url);
HttpsURLConnection con = null;
if (useProxy)
{
con = (HttpsURLConnection) urlObj.openConnection(proxy);
}
else
{
con = (HttpsURLConnection) urlObj.openConnection();
}
// add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Content-Type", "application/json; charset=utf-8");
con.setRequestProperty("Host", urlObj.getHost());
con.setRequestProperty("Connection", "Keep-Alive");
// con.setRequestProperty("Accept-Encoding", "gzip");
String urlParameters = "{\"lat\":" + lat + ",\"lon\":" + lon + "}";
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
// System.out.println("\nSending 'POST' request to URL : " + url);
// System.out.println("Post parameters : " + urlParameters);
// System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String inputLine;
response = new StringBuffer();
while ((inputLine = in.readLine()) != null)
{
response.append(inputLine);
}
in.close();
// print result
// System.out.println(response.toString());
}
catch (Exception e)
{
e.printStackTrace();
}
return response.toString();
}
How can I make this return the server response no matter what the server returns and even if the server responds with 403 code (or any other response code)?

You only need to add an if block to make the code more robust like below:
public String ping(String lat, String lon)
{
StringBuffer response = null;
try
{
String url = "https://api.mysite.com";
URL urlObj = new URL(url);
HttpsURLConnection con = null;
if (useProxy)
{
con = (HttpsURLConnection) urlObj.openConnection(proxy);
}
else
{
con = (HttpsURLConnection) urlObj.openConnection();
}
// add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Content-Type", "application/json; charset=utf-8");
con.setRequestProperty("Host", urlObj.getHost());
con.setRequestProperty("Connection", "Keep-Alive");
// con.setRequestProperty("Accept-Encoding", "gzip");
String urlParameters = "{\"lat\":" + lat + ",\"lon\":" + lon + "}";
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
response = readResponse(con.getInputStream());
} else {
response = readResponse(con.getErrorStream());
}
// print result
System.out.println(response.toString());
}
catch (Exception e)
{
e.printStackTrace();
}
return response.toString();
}
private StringBuffer readResponse(InputStream in) {
BufferedReader in = new BufferedReader(new InputStreamReader(in));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null)
{
response.append(inputLine);
}
in.close();
return response;
}
HTH.

How to stream a JSON object to a HttpURLConnection POST request

I can not see what is wrong with this code:
JSONObject msg; //passed in as a parameter to this method
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setDoInput(true);
httpCon.setUseCaches(false);
httpCon.setRequestProperty( "Content-Type", "application/json" );
httpCon.setRequestProperty("Accept", "application/json");
httpCon.setRequestMethod("POST");
OutputStream os = httpCon.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
msg.write(osw);
osw.flush();
osw.close();
os.close(); //probably overkill
On the server, I am getting no post content at all, a zero length string.

Try
...
httpCon.setRequestMethod("POST");
httpCon.connect(); // Note the connect() here
...
OutputStream os = httpCon.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");
...
osw.write(msg.toString());
osw.flush();
osw.close();
to send data.
to retrieve data try:
BufferedReader br = new BufferedReader(new InputStreamReader( httpCon.getInputStream(),"utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
System.out.println(""+sb.toString());

public String sendHTTPData(String urlpath, JSONObject json) {
HttpURLConnection connection = null;
try {
URL url=new URL(urlpath);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Accept", "application/json");
OutputStreamWriter streamWriter = new OutputStreamWriter(connection.getOutputStream());
streamWriter.write(json.toString());
streamWriter.flush();
StringBuilder stringBuilder = new StringBuilder();
if (connection.getResponseCode() == HttpURLConnection.HTTP_OK){
InputStreamReader streamReader = new InputStreamReader(connection.getInputStream());
BufferedReader bufferedReader = new BufferedReader(streamReader);
String response = null;
while ((response = bufferedReader.readLine()) != null) {
stringBuilder.append(response + "\n");
}
bufferedReader.close();
Log.d("test", stringBuilder.toString());
return stringBuilder.toString();
} else {
Log.e("test", connection.getResponseMessage());
return null;
}
} catch (Exception exception){
Log.e("test", exception.toString());
return null;
} finally {
if (connection != null){
connection.disconnect();
}
}
}`
call this methopd in doitbackground in asynctask

HttpURLConnection is cumbersome to use. With DavidWebb, a tiny wrapper around HttpURLConnection, you can write it like this:
JSONObject msg; //passed in as a parameter to this method
Webb webb = Webb.create();
JSONObject result = webb.post("http://my-url/path/to/res")
.useCaches(false)
.body(msg)
.ensureSuccess()
.asJsonObject()
.getBody();
If you don't like it, there is a list of alternative libraries on the link provided.
Why should we all write the same boilerplate code every day? BTW the code above is more readable and less error-prone. HttpURLConnection has an awful interface. This has to be wrapped!

Follow this example:
public static PricesResponse getResponse(EventRequestRaw request) {
// String urlParameters = "param1=a&param2=b&param3=c";
String urlParameters = Piping.serialize(request);
HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters);
PricesResponse response = null;
try {
// POST
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
// RESPONSE
BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8));
String json = Buffering.getString(reader);
response = (PricesResponse) Piping.deserialize(json, PricesResponse.class);
writer.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
conn.disconnect();
System.out.println("PricesClient: " + response.toString());
return response;
}
public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) {
return RestClient.getConnection(endPoint, "POST", urlParameters);
}
public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) {
System.out.println("ENDPOINT " + endPoint + " METHOD " + method);
HttpURLConnection conn = null;
try {
URL url = new URL(endPoint);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(method);
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/plain");
} catch (IOException e) {
e.printStackTrace();
}
return conn;
}

this without json String post data to server
class PostLogin extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... params) {
String response = null;
Uri.Builder builder= new Uri.Builder().appendQueryParameter("username","amit").appendQueryParameter("password", "amit");
String parm=builder.build().getEncodedQuery();
try
{
response = postData("your url here/",parm);
}catch (Exception e)
{
e.printStackTrace();
}
Log.d("test", "response string is:" + response);
return response;
}
}
private String postData(String path, String param)throws IOException {
StringBuffer response = null;
URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
// connection.setRequestProperty("Content-Type", "application/json");
// connection.setRequestProperty("Accept", "application/json");
OutputStream out = connection.getOutputStream();
out.write(param.getBytes());
out.flush();
out.close();
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
response = new StringBuffer();
while ((line = br.readLine()) != null) {
response.append(line);
}
br.close();
}
return response.toString();
}