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How to create a cookie and use it in HttpURLConnection?

I have the following python code which creates a cookie and adds it to the session. What would be the equivalent java code for it using HttpURLConnection? I basically want to do a HTTP POST request using the generated cookie.
session = requests.session()
session.auth = (username, password)
try:
token = session.get(SITEMINDER_URL % server, verify=False)
session.cookies.update(dict(SMSESSION=json.loads(token.content)['SMSESSION']))
except Exception as ex:
raise Exception("Failed in authenticating with siteminder", ex)
response = session.post(api_url, headers=headers, verify=False, json=data)

You would use something like this:
HttpURLConnection httpconn = < some source to get a HttpURLConnection >;
String cookieName = "SMSESSION"; // note this is the default but SM can use other prefixes
String cookieValue = < your token content >;
httpurl.setRequestProperty("Cookie", cookieName + "=" + cookieValue);
Also, from the javadocs: NOTE: HTTP requires all request properties which can legally have multiple instances with the same key to use a comma-separated list syntax which enables multiple properties to be appended into a single property
Which leads me to pointing out that using the HttpUrlConnection directly is really clumsy. I recommend you look at an HTTP client library such as Apache HTTP Client http://hc.apache.org/httpcomponents-client-ga/

In my opinion, you can just create an HttpUrlConnection object assigning a List of Cookies as follows:
List<String> cookies = new ArrayList<>();
//Or using a map With entries: Key and value for each cookie
cookies.add("User-Agent=MyUserAgent"); //etc...
URL site = new URL("https://myurl.com");
HttpsURLConnection conn = (HttpsURLConnection) site.openConnection();
for (String string: cookies) {
conn.setRequestProperty("Cookie", string);
}
However this is the simplest but not the best way to do so.

To get higher abstraction for Cookie use CookieManager and CookieStore classes. Here is an example:
HttpURLConnection connection
CookieManager cookieManager = new CookieManager();
HttpCookie cookie = new HttpCookie("cookieName","cookieValue");
cookieManager.getCookieStore().add(null,cookie);
connection.setRequestProperty("Cookie", String.join( ";", cookieManager.getCookieStore().getCookies()));

Try This:
URL url = new URL("http://www.example.com");
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestProperty("Cookie", "name1=value1; name2=value2");
conn.connect();

Authorization issue when reading sheet

I want to read a table from Google Sheets from my android application.
I want to do that by Google Sheets APIs.
I declared the sheet as public, created API key and tried to send the GET service call:
https://sheets.googleapis.com/v4/spreadsheets/{My Sheet key}/values/responses:append?key={My API credential key}
I get 401 code.
Response:
Request is missing required authentication credential. Expected OAuth
2 access token, login cookie or other valid authentication credential.
See
https://developers.google.com/identity/sign-in/web/devconsole-project.
My code:
private static final String SHEET_URL = "https://sheets.googleapis.com/v4/spreadsheets/1d534sQ5xaNbr65wMM_qH2yjXo3EPrrp3o34z-Foledg/values/responses:append?key=AIzaSyDT88Nq6jhtaKH-vIVEuvGO1d9Sx8ewR0w";
public String GetConanimList() throws Exception {
URL url = new URL(SHEET_URL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("GET");
conn.setRequestProperty("Content-Type", "application/json");
OutputStream os = conn.getOutputStream();
String jsonPayload = null;
//os.write(jsonPayload.getBytes());
os.flush();
os.close();
int statusCode = conn.getResponseCode();
System.out.println("Response from WA Gateway: \n");
System.out.println("Status Code: " + statusCode);
BufferedReader br = new BufferedReader(new InputStreamReader(
(statusCode == 200) ? conn.getInputStream() : conn.getErrorStream()
));
String output;
String response = "";
while ((output = br.readLine()) != null) {
response = response + output;
}
conn.disconnect();
return response;
}
What am I missing? Thanks.

To use Google Sheets API, you need to authorize your requests.
There are two ways to identify your application: using an OAuth 2.0
token (which also authorizes the request) and/or using the
application's API key. Here's how to determine which of those
options to use:
If the request requires authorization (such as a request for an individual's private data), then the application must provide an OAuth 2.0 token with the request. The application may also provide the API key, but it doesn't have to.
If the request doesn't require authorization (such as a request for public data), then the application must provide either the API key or an OAuth 2.0 token, or both—whatever option is most convenient for you.
You can also refer to the quickstart projects available as a guide on how to correctly implement this.

How to move from URL to URL in Java (Re-use reader-object?)

Sorry for the very basic question, I am new to Java.
To get data from an URL I use code like this
URL url = new URL(BaseURL+"login?name=foo");
URLConnection yc = url.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
while ((inputLine = in.readLine()) != null)
...
That works perfectly fine. When I now want to continue and send the next command to the server (like ".../getStatus"), do I need to create these objects over and over again, or is there a smarter way?
Thanks!

You have to call openConnection again in order to get a new URLConnection. The HttpURLConnection does internal caching, though, so if the HTTP-server supports Connection: keep-alive the underlying connection to the server will be reused so it's not that bad as it originally might look. It's just hidden from you.

I looked into the Apache HttpComponents (HttpClient) and it still requires a lot of code. As I don't need cookie-handling (it's only a simple RESTful server giving json-blocks as responses) I'm going for a very simple solution:
public static String readStringFromURL(String requestURL) throws IOException
{
URL u = new URL(requestURL);
try (InputStream in = u.openStream()) {
return new String(in.readAllBytes(), StandardCharsets.UTF_8);
}
}
For me that looks like a perfect solution, but as mentioned, I am new to Java and open (and thankful) for hints...

how to connect to REST web service from Java application

I have to test the EPA's Data Exchange Web Services. Since it is difficult to create 100 accounts, buildings, energy usage distributions, etc. I want to automate the process. I searched for code examples to do a simple GET. The best one I found was at http://pic.dhe.ibm.com/infocenter/tivihelp/v10r1/index.jsp?topic=%2Fcom.ibm.taddm.doc_7.2%2FSDKDevGuide%2Ft_cmdbsdk_restapi_java.html. I modified this for my purposes.
With the certificate, it is throwing an error at that line
Without the certificate (commented out), the connection is timing out and throwing the exception at getResponseCode().
I'm not sure:
What is the correct way of submitting a certificate
If I am sending the credentials correctly
If my code is incomplete, and therefore, the application is unable to get the response code
I should be using Eclipse EE (with Web Tools Platform) and create Project > Web Application, instead of Eclipse Juno (without WTP)
Thank you in advance.
package Package1;
import java.io.*;
import java.util.*;
import java.lang.StringBuffer;
import java.net.*;
import java.net.HttpURLConnection;
import javax.net.ssl.HttpsURLConnection;
public class Class1 {
public static void main (String args[]){
try{
// set this property to the location of the cert file
System.setProperty("javax.net.ssl.trustStore","C:/Documents and Settings/bhattdr/Desktop/-.energystar.gov.der");
String username = "yy777PPP";
String password = "yy777PPP";
String userpass = "";
URL url = new URL("https://portfoliomanager.energystar.gov/wstest/account");
// URLConnection uc = url.openConnection();
HttpsURLConnection uc = (HttpsURLConnection) url.openConnection();
userpass = username + ":" + password;
String basicAuth = "Basic " + javax.xml.bind.DatatypeConverter.printBase64Binary(userpass.getBytes());
System.out.println("sending request...");
uc.setRequestMethod("GET");
uc.setAllowUserInteraction(false);
uc.setDoOutput(true);
uc.setRequestProperty( "Content-type", "text/xml" );
uc.setRequestProperty( "Accept", "text/xml" );
uc.setRequestProperty ("Authorization", basicAuth);
System.out.println(uc.getRequestProperties());
// uc.setRequestProperty( "authorization", "Basic " + encode("administrator:collation"));
// Map headerFields = uc.getHeaderFields();
// System.out.println("header fields are: " + headerFields);
int rspCode = uc.getResponseCode();
if (rspCode == 200) {
InputStream is = uc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String nextLine = br.readLine();
while (nextLine != null) {
System.out.println(nextLine);
nextLine = br.readLine();
}
}
}
catch(IOException e) {
e.printStackTrace();
}
}
}

You don't need to roll your own.
If you want to write something, you can use Jersey, which has existing classes to act as Rest Clients (Rest clients for Java?)
There are plenty of apps which exercise rest apis which you can use if you don't want to write something. Google turns up plenty (like http://code.google.com/p/rest-client/)

You're using a DER file as your key store which is not supported by Java
Crypto normally. Use the keytool to create a JKS or some other supported keystore and then refer to it.

AMong all the frameworks for REST-Clients... did you try OpenFeign? It's a components from the NetFlix stack. Easy to use and fits into all the other
components of NetFlix.
Give it a try: https://github.com/OpenFeign/feign

Download File from server that uses Icefaces form based authentication

I am a newbie to ICEfaces and i have a requirement where i need to download a document from a given url (http://ipaddress/formexec?objectid=201).
This URL uses a form based authentication that is deployed through ICEFaces.
i tracked the request of this URL and i get the following line:
&ice.submit.partial=false&ice.event.target=loginForm%3Aj_id33&ice.event.captured=loginForm%3Aj_id33
Is there any libraries or code to download the document by successfully passing the username and password.

You need to extract the jsessionid from the Set-Cookie response header and append it as URL attribute to the subsequent requests as http://example.com/path/page.jsf;jsessionid=XXX.
Here's a kickoff example with help of "plain vanilla" java.net.URLConnection:
// Prepare stuff.
String loginurl = "http://example.com/login";
String username = "itsme";
String password = "youneverguess";
URLConnection connection = null;
InputStream response = null;
// First get jsessionid (do as if you're just opening the login page).
connection = new URL(loginurl).openConnection();
response = connection.getInputStream(); // This will actually send the request.
String cookie = connection.getHeaderField("Set-Cookie");
String jsessionid = cookie.split(";")[0].split("=")[1]; // This assumes JSESSIONID is first field (normal case), you may need to change/finetune it.
String jsessionidurl = ";jsessionid=" + jsessionid;
response.close(); // We're only interested in response header. Ignore the response body.
// Now do login.
String authurl = loginurl + "/j_security_check" + jsessionidurl;
connection = new URL(authurl).openConnection();
connection.setDoOutput(true); // Triggers POST method.
PrintWriter writer = new PrintWriter(new OutputStreamWriter(connection.getOutputStream()));
writer.write("j_username=" + URLEncoder.encode(username, "UTF-8")
+ "&j_password=" + URLEncoder.encode(password, "UTF-8"));
writer.close();
response = connection.getInputStream(); // This will actually send the request.
response.close();
// Now you can do any requests in the restricted area using jsessionid. E.g.
String downloadurl = "http://example.com/download/file.ext" + jsessionidurl;
InputStream download = new URL(downloadurl).openStream();
// ...
To achieve the same with less bloated code, consider Apache Commons HttpComponents Client.

Form based auth is not much different from other requests. All you have to do is to submit an a request to the auth form providing required parameters, such as user and password and in some cases additional token that you would have to get from the source page. Then you need to get cookies from the auth response or session id parameter and copy them to your next request that will fetch the data.