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entity must be null for http method GET

I'm trying to consume an external api exposed a payment provider.
I user Jersey and javax.ws.rs for request, because I can easily send authent with Digest.
But when it comes to make the request, a GET with payload, Jersey returns
> IllegalStateException. Entity must be null for http method GET
CashTransactionResponse responseData = null;
//We connect to intouch server
String requestUrl = rootUrlTouchPay + agency.getAgencyCode() + "/" + IntouchMethodApis.TRANSACTION + "?loginAgent=" + agency.getLogin() + "&passwordAgent=" + agency.getPassword();
ClientConfig clientConfig = new ClientConfig();
//Open Digest authentication
HttpAuthenticationFeature feature = HttpAuthenticationFeature.digest(BASIC_LOGIN, BASIC_PWD);
clientConfig.register(feature);
clientConfig.register(JacksonFeature.class);
//Create new rest client
Client client = ClientBuilder.newClient(clientConfig);
clientConfig.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true);
//Set the url
WebTarget webTarget = client.target(requestUrl);
Invocation.Builder invocationBuilder = webTarget.request(javax.ws.rs.core.MediaType.APPLICATION_JSON);
logger.info("Initialisation of cashout service successful for cash");
// create request
Gson gson = new Gson();
String transactionString = gson.toJson(cashRequest);
Response response = null;
// start the response
if (cashRequest.getServiceCode().contains(TelecomEnum.WAVE.name().toUpperCase())) {
response = invocationBuilder.method("GET", Entity.entity(transactionString, javax.ws.rs.core.MediaType.APPLICATION_JSON));
} else {
response = invocationBuilder.put(Entity.entity(transactionString, javax.ws.rs.core.MediaType.APPLICATION_JSON));
}
Please how could i do to send my GET request with body ?
Thanks

I believe the problem is in
Client client = ClientBuilder.newClient(clientConfig);
clientConfig.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true);
The client copied the values from clientConfig and any further settings on clientConfig do not have any impact on the client.
Either switch the lines or set the ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION property on the client.

Instead of doing an invocationBuilder.method("GET", ...), use invocationBuilder.post(entity), as described here. This will allow you to POST your transaction String to the endpoint.

Basic Authentication for JAVA Application using OkHttp

First I wanted to authenticate my java application using OkHttp and then after authentication the response returns a session ID(key) that I wanted to use in subsequent API calls. below is the code that I am using to achieve this.
String url = "my application url";
String username = "xxx";
String password = "zzz";
String userpass = username + ":" + password;
String basicAuth = "Basic :" + new String(Base64.getEncoder().encode(userpass.getBytes()));
OkHttpClient client = new OkHttpClient();
Response response ;
Request request = new Request.Builder()
.url(url)
.addHeader("Authorization", basicAuth)
.build();
response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
System.out.println(response.body().string());
but its throwing an error saying
{"responseStatus":"FAILURE","responseMessage":"Request method 'GET' not supported","errorCodes":null,"errors":[{"type":"METHOD_NOT_SUPPORTED","message":"Request method 'GET' not supported"}],"errorType":"GENERAL"}
can someone please help me to solve this. or if any have any other idea to authenticate a java application using okhttp then please suggest...

You should use the helper classes to avoid most of the logic for username and password.
https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/Authenticate.java
String credential = Credentials.basic("jesse", "password1");
return response.request().newBuilder()
.header("Authorization", credential)
.build();
Assuming this API is POST and not GET also follow
https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PostString.java
Request request = new Request.Builder()
.url("https://api.github.com/markdown/raw")
.post(RequestBody.create(postBody, MEDIA_TYPE_MARKDOWN))
.build();

You had it all right already. Just a small fix needed:
String basicAuth = "Basic " + new String(Base64.getEncoder().encode(userpass.getBytes()));
i.e you just need to remove extra ':' as it's already taken care of in .addHeader("Authorization", basicAuth) part.

Sending the session id from an Android App to a Jersey web service

I got an Android application which is supposed to communicate with a web service which was implemented using Jersey and Jetty.
I can read the incoming session Id using this code:
private static void getCookie(HttpResponse httpResponse)
{
Header[] headers = httpResponse.getAllHeaders();
for (int i=0; i < headers.length; i++)
{
Header h = headers[i];
String s1 = h.getName();
if(s1.equals("Set-Cookie"))
{
sessionCookieValue = h.getValue().split(";",2)[0];
return;
}
}
}
This seems to work and I get a value like this in the cookie value: JSESSIONID=8pdfuwgduykls5cvj971ylrc
The problem is that I don't seem to send it properly. The web service is injected with a HttpServletRequest parameter which is supposed to hold the session id but it doesn't.
The way I'm trying to pass it is like this:
DefaultHttpClient client = new DefaultHttpClient();
CookieStore cookieStore = new BasicCookieStore();
BasicClientCookie cookie = new BasicClientCookie("JSESSIONID", sessionCookieValue);
cookie.setPath("/");
cookie.setDomain(MyApplication.WEB_SERVICE_BASE_ADDRESS); //"192.168.200.158/"
cookieStore.addCookie(cookie);
client.setCookieStore(cookieStore);
HttpResponse httpResponse;
try
{
httpResponse = client.execute(request);
...
}
Why isn't the session id injected to the request in the web service?

I have finally figured out the problem.
The initial comments were correct - the cookie's key in the BasicClientCookie should be "JESSIONID". The path and domain should be set like I did there.
The main issue was simply removing the "JSESSIONID=" prefix from the `sessionCookieValue. After I removed it, everything worked.

Java - Sending a post request with HtmlUnit

Can't really find any help on this but I've been trying to send a post request with HtmlUnit. The code I have is:
final WebClient webClient = new WebClient();
// Instead of requesting the page directly we create a WebRequestSettings object
WebRequest requestSettings = new WebRequest(
new URL("www.URLHERE.com"), HttpMethod.POST);
// Then we set the request parameters
requestSettings.setRequestParameters(new ArrayList());
requestSettings.getRequestParameters().add(new NameValuePair("name", "value"));
// Finally, we can get the page
HtmlPage page = webClient.getPage(requestSettings);
Is there an easier way I could carry out a POST request?

This is how it's done
public void post() throws Exception
{
URL url = new URL("YOURURL");
WebRequest requestSettings = new WebRequest(url, HttpMethod.POST);
requestSettings.setAdditionalHeader("Accept", "*/*");
requestSettings.setAdditionalHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
requestSettings.setAdditionalHeader("Referer", "REFURLHERE");
requestSettings.setAdditionalHeader("Accept-Language", "en-US,en;q=0.8");
requestSettings.setAdditionalHeader("Accept-Encoding", "gzip,deflate,sdch");
requestSettings.setAdditionalHeader("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.3");
requestSettings.setAdditionalHeader("X-Requested-With", "XMLHttpRequest");
requestSettings.setAdditionalHeader("Cache-Control", "no-cache");
requestSettings.setAdditionalHeader("Pragma", "no-cache");
requestSettings.setAdditionalHeader("Origin", "https://YOURHOST");
requestSettings.setRequestBody("REQUESTBODY");
Page redirectPage = webClient.getPage(requestSettings);
}
You can customize it however you want. Add/remove headers, add/remove request body, etc ...

There are n numbers of possible libraries using which you can call rest web services.
1) Apache Http client
2) Retrofit from Square
3) Volley from google
I have used Http Apache client and Retrofit both. Both are awesome.
Here is code example of Apache HTTP client to send Post request
String token = null;
HttpClient httpClient = HttpClientBuilder.create().build();
HttpPost postRequest = new HttpPost(LOGIN_URL);
StringBuilder sb = new StringBuilder();
sb.append("{\"userName\":\"").append(user).append("\",").append("\"password\":\"").append(password).append("\"}");
String content = sb.toString();
StringEntity input = new StringEntity(content);
input.setContentType("application/json");
postRequest.setHeader("Content-Type", "application/json");
postRequest.setHeader("Accept", "application/json");
postRequest.setEntity(input);
HttpResponse response = httpClient.execute(postRequest);
if (response.getStatusLine().getStatusCode() != 201)
{
throw new RuntimeException("Failed : HTTP error code : " + response.getStatusLine().getStatusCode());
}
Header[] headers = response.getHeaders("X-Auth-Token");
if (headers != null && headers.length > 0)
{
token = headers[0].getValue();
}
return token;

Consuming web service & storing cookies

This method is used to consume a web service which I also control. The web service sets cookies to keep the user logged in.
This all works fine through a browser. i.e. I can call the login url, it will cookie my browser, and subsequent access to the web service recognizes my cookies.
In android, I can get a successful return on my login, but the cookies do not seem to be setting.
You can see where this code prints the cookie data to the output. It prints the cookie when it hits the login script, but for subsequent calls to this function, it does not recognize the cookie anymore.
Here's the code I'm using, I started from an example someone else posted:
private JSONObject getResponse(String func, List<NameValuePair> args) throws Exception {
HttpClient httpclient = new DefaultHttpClient();
try {
// Create a local instance of cookie store
CookieStore cookieStore = new BasicCookieStore();
// Create local HTTP context
HttpContext localContext = new BasicHttpContext();
// Bind custom cookie store to the local context
localContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
HttpPost put= new HttpPost("http://example.com/api/" + func);
if (args != null) {
put.setEntity(new UrlEncodedFormEntity(args));
}
System.out.println("executing request " + put.getURI());
// Pass local context as a parameter
HttpResponse response = httpclient.execute(put, localContext);
HttpEntity entity = response.getEntity();
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
}
List<Cookie> cookies = cookieStore.getCookies();
for (int i = 0; i < cookies.size(); i++) {
System.out.println("Local cookie: " + cookies.get(i));
}
// Consume response content
//EntityUtils.consume(entity);
System.out.println("----------------------------------------");
InputStream instream = entity.getContent();
String result = convertStreamToString(instream);
instream.close();
entity.consumeContent();
System.out.println("JSON Output: " + result);
return new JSONObject(result);
} finally {
// When HttpClient instance is no longer needed,
// shut down the connection manager to ensure
// immediate deallocation of all system resources
httpclient.getConnectionManager().shutdown();
}
}

That might be because your HttpClient and CookieStore are local to getResponse. Try making them global so they persist onto subsequent calls.

When you are trying to access locked content on a url call you need to manually set a cookie for the next coming call, which can be done using:
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setInstanceFollowRedirects(false);
httpURLConnection.setRequestProperty("Host", domainOfYourCookie);
httpURLConnection.setRequestProperty("Cookie", valueOfYourCookie);
I have written another answer regarding this topic, which you can find here.