I would like to open an URL and submit the following parameters to it, but it only seems to work if I add the BufferedReader to my code. Why is that?
Send.php is a script what will add an username with a time to my database.
This following code does not work (it does not submit any data to my database):
final String base = "http://awebsite.com//send.php?";
final String params = String.format("username=%s&time=%s", username, time);
final URL url = new URL(base + params);
final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("User-Agent", "Agent");
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.connect();
But this code does work:
final String base = "http://awebsite.com//send.php?";
final String params = String.format("username=%s&time=%s", username, time);
final URL url = new URL(base + params);
final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("User-Agent", "Agent");
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.connect();
final BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
connection.disconnect();
As far as I know. When you called the connect() function, it will only create the connection.
You need to at least call the getInputStream() or getResponseCode() for the connection to be committed so that the server that the url is pointing to able to process the request.
I am trying to write a simple HTTP server in Java that can handle POST requests. While my server successfully receives the GET, it crashes on the POST.
Here is the server
public class RequestHandler {
public static void main(String[] args) throws Exception {
HttpServer server = HttpServer.create(new InetSocketAddress(8080), 0);
server.createContext("/requests", new MyHandler());
server.setExecutor(null); // creates a default executor
server.start();
}
static class MyHandler implements HttpHandler {
public void handle(HttpExchange t) throws IOException {
String response = "hello world";
t.sendResponseHeaders(200, response.length());
System.out.println(response);
OutputStream os = t.getResponseBody();
os.write(response.getBytes());
os.close();
}
}
}
And here is the Java code I use to send the POST
// HTTP POST request
private void sendPost() throws Exception {
String url = "http://localhost:8080/requests";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";
// 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;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
//print result
System.out.println(response.toString());
}
Each time the POST request crashes on this line
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
but when I change the URL to the one provided in the example where I found this it works.
Instead of
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
Use
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
You are connecting to a URL which is not HTTPS. When you call obj.openConnection(), it decides whether the connection is HTTP or HTTPS, and returns the appropriate object. When it's http, it won't return an HttpsURLConnection, so you cannot convert to it.
However, since HttpsURLconnection extends HttpURLConnection, using HttpURLConnection will work for both http and https URLs. The methods that you are calling in your code all exist int the HttpURLConnection class.
URL url = new URL("http://maps.google.com/maps/api/geocode/json?address=1600%20Amphitheatre%20Parkway&sensor=false&client_id=my_client_id&key=my_key");
URLConnection urlConnection = url.openConnection();
HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;
httpURLConnection.setDoInput(true);
httpURLConnection.setRequestMethod("GET");
InputStream in = httpURLConnection.getInputStream();
Its giving connection refused exception.
You forgot to actually connect:
URL url = new URL("yoururl");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setDoInput(true);
httpURLConnection.setRequestMethod("GET");
try {
// open the connection and get results as InputStream.
httpURLConnection.connect();
InputStream in = httpURLConnection.getInputStream();;
// do more things
} finally {
httpURLConnection.disconnect();
}
Also you can modify how you encode your URL to avoid errors:
private String REQUEST_URL = "http://maps.google.com/maps/api/geocode/json";
private String address = "1600 Amphitheatre Parkway";
URL url = new URL(REQUEST_URL + "?address=" + URLEncoder.encode(address, "UTF-8") + "&sensor=false&client_id=my_client_id&key=my_key"););
url = new URL(UPLOAD_URL);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("PUT");
urlConnection.setRequestProperty("content-type", "application/json");
urlConnection.setFixedLengthStreamingMode(responseJSONArray.toString(2).getBytes("UTF8").length);
urlConnection.setDoInput(false);
urlConnection.setDoOutput(true);
urlConnection.setConnectTimeout(this.CONNECT_TIMEOUT);
urlConnection.connect();
OutputStream output = urlConnection.getOutputStream();
output.write(responseJSONArray.toString(2).getBytes("UTF8"));
output.close();
I've also already earlier set the Authenticator with:
Authenticator.setDefault(new Authenticator()
{
#Override
protected PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(loginNameString, passwordString.toCharArray());
}
});
I supply correct login details, but the server responds with a 401 code. (A similar GET-request works though.) On top of which, the method getPasswordAuthentication() is not being called in the process of connecting and writing to the stream. (I know this because I put in Log.v("app", "password here").)
Why is that?
I'm not able to answer to why using Authenticator does not work, but I usually use this approach:
String webPage = "http://192.168.1.1";
String name = "admin";
String password = "admin";
String authString = name + ":" + password;
byte[] authEncBytes = Base64.encodeBase64(authString.getBytes());
String authStringEnc = new String(authEncBytes);
URL url = new URL(webPage);
URLConnection urlConnection = url.openConnection();
urlConnection.setRequestProperty("Authorization", "Basic " + authStringEnc);
InputStream is = urlConnection.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
Try it. Using basic auth should be enough.
How do I connect to a remote URL in Java which requires authentication. I'm trying to find a way to modify the following code to be able to programatically provide a username/password so it doesn't throw a 401.
URL url = new URL(String.format("http://%s/manager/list", _host + ":8080"));
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
There's a native and less intrusive alternative, which works only for your call.
URL url = new URL(“location address”);
URLConnection uc = url.openConnection();
String userpass = username + ":" + password;
String basicAuth = "Basic " + new String(Base64.getEncoder().encode(userpass.getBytes()));
uc.setRequestProperty ("Authorization", basicAuth);
InputStream in = uc.getInputStream();
You can set the default authenticator for http requests like this:
Authenticator.setDefault (new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication ("username", "password".toCharArray());
}
});
Also, if you require more flexibility, you can check out the Apache HttpClient, which will give you more authentication options (as well as session support, etc.)
You can also use the following, which does not require using external packages:
URL url = new URL(“location address”);
URLConnection uc = url.openConnection();
String userpass = username + ":" + password;
String basicAuth = "Basic " + javax.xml.bind.DatatypeConverter.printBase64Binary(userpass.getBytes());
uc.setRequestProperty ("Authorization", basicAuth);
InputStream in = uc.getInputStream();
If you are using the normal login whilst entering the username and password between the protocol and the domain this is simpler. It also works with and without login.
Sample URL: http://user:pass#example.com/url
URL url = new URL("http://user:pass#example.com/url");
URLConnection urlConnection = url.openConnection();
if (url.getUserInfo() != null) {
String basicAuth = "Basic " + new String(new Base64().encode(url.getUserInfo().getBytes()));
urlConnection.setRequestProperty("Authorization", basicAuth);
}
InputStream inputStream = urlConnection.getInputStream();
Please note in the comment, from valerybodak, below how it is done in an Android development environment.
As I have came here looking for an Android-Java-Answer I am going to do a short summary:
Use java.net.Authenticator as shown by James van Huis
Use Apache Commons HTTP Client, as in this Answer
Use basic java.net.URLConnection and set the Authentication-Header manually like shown here
If you want to use java.net.URLConnection with Basic Authentication in Android try this code:
URL url = new URL("http://www.example.com/resource");
URLConnection urlConnection = url.openConnection();
String header = "Basic " + new String(android.util.Base64.encode("user:pass".getBytes(), android.util.Base64.NO_WRAP));
urlConnection.addRequestProperty("Authorization", header);
// go on setting more request headers, reading the response, etc
Was able to set the auth using the HttpsURLConnection
URL myUrl = new URL(httpsURL);
HttpsURLConnection conn = (HttpsURLConnection)myUrl.openConnection();
String userpass = username + ":" + password;
String basicAuth = "Basic " + new String(Base64.getEncoder().encode(userpass.getBytes()));
//httpsurlconnection
conn.setRequestProperty("Authorization", basicAuth);
few of the changes fetched from this post. and Base64 is from java.util package.
Be really careful with the "Base64().encode()"approach, my team and I got 400 Apache bad request issues because it adds a \r\n at the end of the string generated.
We found it sniffing packets thanks to Wireshark.
Here is our solution :
import org.apache.commons.codec.binary.Base64;
HttpGet getRequest = new HttpGet(endpoint);
getRequest.addHeader("Authorization", "Basic " + getBasicAuthenticationEncoding());
private String getBasicAuthenticationEncoding() {
String userPassword = username + ":" + password;
return new String(Base64.encodeBase64(userPassword.getBytes()));
}
Hope it helps!
Use this code for basic authentication.
URL url = new URL(path);
String userPass = "username:password";
String basicAuth = "Basic " + Base64.encodeToString(userPass.getBytes(), Base64.DEFAULT);//or
//String basicAuth = "Basic " + new String(Base64.encode(userPass.getBytes(), Base64.No_WRAP));
HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
urlConnection.setRequestProperty("Authorization", basicAuth);
urlConnection.connect();
Since Java 9, you can do this
URL url = new URL("http://www.example.com");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setAuthenticator(new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication ("USER", "PASS".toCharArray());
}
});
I'd like to provide an answer for the case that you do not have control over the code that opens the connection. Like I did when using the URLClassLoader to load a jar file from a password protected server.
The Authenticator solution would work but has the drawback that it first tries to reach the server without a password and only after the server asks for a password provides one. That's an unnecessary roundtrip if you already know the server would need a password.
public class MyStreamHandlerFactory implements URLStreamHandlerFactory {
private final ServerInfo serverInfo;
public MyStreamHandlerFactory(ServerInfo serverInfo) {
this.serverInfo = serverInfo;
}
#Override
public URLStreamHandler createURLStreamHandler(String protocol) {
switch (protocol) {
case "my":
return new MyStreamHandler(serverInfo);
default:
return null;
}
}
}
public class MyStreamHandler extends URLStreamHandler {
private final String encodedCredentials;
public MyStreamHandler(ServerInfo serverInfo) {
String strCredentials = serverInfo.getUsername() + ":" + serverInfo.getPassword();
this.encodedCredentials = Base64.getEncoder().encodeToString(strCredentials.getBytes());
}
#Override
protected URLConnection openConnection(URL url) throws IOException {
String authority = url.getAuthority();
String protocol = "http";
URL directUrl = new URL(protocol, url.getHost(), url.getPort(), url.getFile());
HttpURLConnection connection = (HttpURLConnection) directUrl.openConnection();
connection.setRequestProperty("Authorization", "Basic " + encodedCredentials);
return connection;
}
}
This registers a new protocol my that is replaced by http when credentials are added. So when creating the new URLClassLoader just replace http with my and everything is fine. I know URLClassLoader provides a constructor that takes an URLStreamHandlerFactory but this factory is not used if the URL points to a jar file.
i did that this way you need to do this just copy paste it be happy
HttpURLConnection urlConnection;
String url;
// String data = json;
String result = null;
try {
String username ="user#gmail.com";
String password = "12345678";
String auth =new String(username + ":" + password);
byte[] data1 = auth.getBytes(UTF_8);
String base64 = Base64.encodeToString(data1, Base64.NO_WRAP);
//Connect
urlConnection = (HttpURLConnection) ((new URL(urlBasePath).openConnection()));
urlConnection.setDoOutput(true);
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Authorization", "Basic "+base64);
urlConnection.setRequestProperty("Accept", "application/json");
urlConnection.setRequestMethod("POST");
urlConnection.setConnectTimeout(10000);
urlConnection.connect();
JSONObject obj = new JSONObject();
obj.put("MobileNumber", "+97333746934");
obj.put("EmailAddress", "danish.hussain#example.com");
obj.put("FirstName", "Danish");
obj.put("LastName", "Hussain");
obj.put("Country", "BH");
obj.put("Language", "EN");
String data = obj.toString();
//Write
OutputStream outputStream = urlConnection.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
writer.write(data);
writer.close();
outputStream.close();
int responseCode=urlConnection.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
//Read
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "UTF-8"));
String line = null;
StringBuilder sb = new StringBuilder();
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
bufferedReader.close();
result = sb.toString();
}else {
// return new String("false : "+responseCode);
new String("false : "+responseCode);
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
ANDROD IMPLEMENTATION
A complete method to request data/string response from web service requesting authorization with username and password
public static String getData(String uri, String userName, String userPassword) {
BufferedReader reader = null;
byte[] loginBytes = (userName + ":" + userPassword).getBytes();
StringBuilder loginBuilder = new StringBuilder()
.append("Basic ")
.append(Base64.encodeToString(loginBytes, Base64.DEFAULT));
try {
URL url = new URL(uri);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.addRequestProperty("Authorization", loginBuilder.toString());
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = reader.readLine())!= null){
sb.append(line);
sb.append("\n");
}
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
if (null != reader){
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}