Cors blocking HTTP delete Method - java

I am getting a CORS error when I try to use my HTTP Delete method.
My Frontend is Angular-ionic and my Server is a Java server. Both are self-made.
I tried to disable CORS in the Browser, by doing so I managed the Request to work and the Error to disappear. Although that's fine, my goal is to make it work every time for EVERY user.
Here is my Code with a bit of Background:
console.log('User Management Service Delete User()');
const myParams = new HttpParams().set('id', this.cookieService.get('AccessToken'));
console.log(myParams);
return this.http.delete(this.endpoint + 'users/delete', { params: myParams});
}
The code above is my FRONTEND (clientside) code. I am simply trying to delete a user.
public int serveUserDelete(HTTPServer.Request req, HTTPServer.Response resp) throws IOException {
Map<String, String> params = req.getParams();
String response;
String paramvalue;
String accessToken;
resp.getHeaders().add("Content-Type", "application/json");
resp.getHeaders().add("Access-Control-Allow-Origin", "*");
resp.getHeaders().add("Access-Control-Allow-Headers", "*");
resp.getHeaders().add("Access-Control-Allow-Credentials", "true");
resp.getHeaders().add("id", "*");
resp.getHeaders().add("Access-Control-Allow-Methods", "OPTIONS, DELETE, POST, GET, PATCH, PUT");
response = "";
//Id aus dem Parameter auslesen
if (params.containsKey("id")) {
//es gibt einen Parameter id. Suche den Wertd dazu
accessToken = params.get("id");
System.out.println(accessToken);
} else {
accessToken = null;
}
response = um.userDelete(accessToken);
resp.send(200, response);
return 0;
}
The Code above now, is my Java server.
The headers were added cause of trial and error.
Here the error I am getting:
Access to XMLHttpRequest at 'http://localhost:8080/umyServerUrl/users/delete?id=u#Yy0NZPLx%266HxYNF%23tv'
from origin 'http://localhost:8100' has been blocked by CORS policy: Response to preflight request doesn't pass access control check:
No 'Access-Control-Allow-Origin' header is present on the requested resource.
threw testing (with disabled browser cors etc.) I found out that the methods on my server work just fine.
Here you can see my "PARAMS" and the Observable of my delete Request printed in the Console:
HttpParams 
{updates: Array(1),
cloneFrom: HttpParams,
encoder: HttpUrlEncodingCodec,
map: null}
cloneFrom:
nullencoder:
HttpUrlEncodingCodec {}[[Prototype]]:
Objectconstructor: class
HttpUrlEncodingCodecdecodeKey: ƒ
decodeKey(key)decodeValue: ƒ
decodeValue(value)encodeKey: ƒ
encodeKey(key)encodeValue: ƒ
encodeValue(value)[[Prototype]]:
Objectmap:
Map(1)[[Entries]]0: {"id" => Array(1)}
key: "id" value: ['hTxYusBwuB7pbUUCkW9E']size: 1[[Prototype]]:
Mapupdates: null[[Prototype]]:
Object
user-management.service.ts:35
**Oberservabel:**
Observable {_isScalar: false, source: Observable,
operator: MapOperator}
operator: MapOperator
project: res => res.body
length: 1
name: ""
arguments: (...)
caller: (...)
[[FunctionLocation]]: http.mjs:1300
[[Prototype]]: ƒ ()
[[Scopes]]: Scopes[2]
thisArg: undefined
[[Prototype]]: Object
call: ƒ call(subscriber, source)
constructor: class MapOperator
[[Prototype]]: Object
source: Observable
operator: FilterOperator {thisArg: undefined, predicate: ƒ}
source: Observable {_isScalar: false, source: Observable, operator: MergeMapOperator}
_isScalar: false
[[Prototype]]: Object
_isScalar: false
[[Prototype]]: Object
PLEASE HELP

This combination of Access-Control headers is invalid.
resp.getHeaders().add("Content-Type", "application/json");
resp.getHeaders().add("Access-Control-Allow-Origin", "*");
resp.getHeaders().add("Access-Control-Allow-Headers", "*");
resp.getHeaders().add("Access-Control-Allow-Credentials", "true");
You cannot set Access-Control-Allow-Origin to * and also allow Access-Control-Allow-Credentials.
For requests without credentials, the literal value "*" can be specified as a wildcard; the value tells browsers to allow requesting code from any origin to access the resource. Attempting to use the wildcard with credentials results in an error.
This might be a large scale issue of the system architecture.
For now you could test setting the Allow-Origin header like this:
resp.getHeaders().add("Access-Control-Allow-Origin", "http://localhost:8100");
However if it's supposed to work from an arbitrary number of clients another architecture might be necessary.
CORS is a security feature. Do not "trial and error" around with security features!

Related

Getting bad response using JRAW

I am trying to read data from reddit using java. I am using JRAW.
Here is my code:
public class Main {
public static void main(String args[]) {
System.out.println('a');
String username = "dummyName";
UserAgent userAgent = new UserAgent("crawl", "com.example.crawl", "v0.1", username);
Credentials credentials = Credentials.script(username, <password>,<clientID>, <client-secret>);
NetworkAdapter adapter = new OkHttpNetworkAdapter(userAgent);
RedditClient reddit = OAuthHelper.automatic(adapter, credentials);
Account me = reddit.me().about();
System.out.println(me.getName());
SubmissionReference submission = reddit.submission("https://www.reddit.com/r/diabetes/comments/9rlkdm/shady_insurance_work_around_to_pay_for_my_dexcom/");
RootCommentNode rcn = submission.comments();
System.out.println(rcn.getDepth());
System.out.println();
// Submission submission1 = submission.inspect();
// System.out.println(submission1.getSelfText());
// System.out.println(submission1.getUrl());
// System.out.println(submission1.getTitle());
// System.out.println(submission1.getAuthor());
// System.out.println(submission1.getCreated());
System.out.println("-----------------------------------------------------------------");
}
}
I am making two requests as of now, first one is reddit.me().about(); and the second is reddit.submission("https://www.reddit.com/r/diabetes/comments/9rlkdm/ shady_insurance_work_around_to_pay_for_my_dexcom/");
The output is:
a
[1 ->] GET https://oauth.reddit.com/api/v1/me?raw_json=1
[<- 1] 200 application/json: '{"is_employee": false, "seen_layout_switch": true, "has_visited_new_profile": false, "pref_no_profanity": true, "has_external_account": false, "pref_geopopular": "GL(...)
dummyName
[2 ->] GET https://oauth.reddit.com/comments/https%3A%2F%2Fwww.reddit.com%2Fr%2Fdiabetes%2Fcomments%2F9rlkdm%2Fshady_insurance_work_around_to_pay_for_my_dexcom%2F?sort=confidence&sr_detail=false&(...)
[<- 2] 400 application/json: '{"message": "Bad Request", "error": 400}'
Exception in thread "main" net.dean.jraw.ApiException: API returned error: 400 (Bad Request), relevant parameters: []
at net.dean.jraw.models.internal.ObjectBasedApiExceptionStub.create(ObjectBasedApiExceptionStub.java:57)
at net.dean.jraw.models.internal.ObjectBasedApiExceptionStub.create(ObjectBasedApiExceptionStub.java:33)
at net.dean.jraw.RedditClient.request(RedditClient.kt:186)
at net.dean.jraw.RedditClient.request(RedditClient.kt:219)
at net.dean.jraw.RedditClient.request(RedditClient.kt:255)
at net.dean.jraw.references.SubmissionReference.comments(SubmissionReference.kt:50)
at net.dean.jraw.references.SubmissionReference.comments(SubmissionReference.kt:28)
at Main.main(Main.java:36)
Caused by: net.dean.jraw.http.NetworkException: HTTP request created unsuccessful response: GET https://oauth.reddit.com/comments/https%3A%2F%2Fwww.reddit.com%2Fr%2Fdiabetes%2Fcomments%2F9rlkdm%2Fshady_insurance_work_around_to_pay_for_my_dexcom%2F?sort=confidence&sr_detail=false&raw_json=1 -> 400
... 6 more
As it can been that my first request gives me a response of my username but in the second response i am getting a bad request 400 error.
To check whether my client ID and client secret were working correctly I did the same request using python PRAW library.
import praw
from praw.models import MoreComments
reddit = praw.Reddit(client_id=<same-as-in-java>, client_secret=<same-as-in-java>,
password=<same-as-in-java>, user_agent='crawl',
username="dummyName")
submission = reddit.submission(
url='https://www.reddit.com/r/redditdev/comments/1x70wl/how_to_get_all_replies_to_a_comment/')
print(submission.selftext)
print(submission.url)
print(submission.title)
print(submission.author)
print(submission.created_utc)
print('-----------------------------------------------------------------')
This gives the desired result without any errors so the client secret details must be working.
The only doubt I have is in the user agent creation in java UserAgent userAgent = new UserAgent("crawl", "com.example.crawl", "v0.1", username);.
I followed the following link.
What exactly does the target platform, the unique ID or the version mean. I tried to keep the same format as in the link. Also using the same username as in other places. On the other hand the user_agent in python was a string crawl.
Please tell me if I am missing anything and what could be the issue.
Thank you
P.S. I want to do this in java. not python.
Since your first query is working the credentials are correct. In JRAW don't give the whole URL but only the id in the submission function.
Change this
SubmissionReference submission = reddit.submission("https://www.reddit.com/r/diabetes/comments/9rlkdm/shady_insurance_work_around_to_pay_for_my_dexcom/");
to this
SubmissionReference submission = reddit.submission("9rlkdm");
where the id is the random string after /comment/ in the URL.
Hope this helps.

the difference between Postman and POST request in Java

I need to get some respones from some URL.
For this purpose I use http://unirest.io/java.html and Java.
Map<String, String> map = new HashMap<>();
map.put(key1, value1);
...
map.put(keyN, valueN);
String authToken = "{token}";
HttpResponse<String> response = Unirest.post(url)
.header("Authorization","Bearer " + authToken)
.header("Content-Type", "application/json")
.fields(map)
.asString();
As a result I receive response.getStatus() = 302 and some unexpected body.
At the same time I use Postman software to get the same responses. The settings are the following:
POST: url
Authorization: Type -> Bearer Token; Token = {{authToken}} // get the value from the previous request
Header :
"Authorization" : "Bearer " + {{authToken}}
Content-Type: application/json
Body:
{
key1 : value1,
...
keyN : valueN
}
And I get some expected response.
What makes the difference?
A 302 is a redirect response. Is it possible Postman is following the redirect and returning the resultant page? Take a look at the Location header in the response you get in Java, and see if following that gives you the same results you're seeing in Postman.

Lagom Send custom header

I'm working on Lagom POC on sending POST request to Non lagom service with custom Header. In my case I'm trying to hit postman-echo to test the custom header.
However, it looks the headers are not set though I made code changes accordingly:
public CompletionStage<DsapAuthorizationResponse> hitAPI(AuthorizationRequest request) {
DsapWSRequest dsapWSRequest = new DsapWSRequest();
dsapWSRequest.username = request.username;
dsapWSRequest.password = request.password;
CompletionStage<DsapAuthorizationResponse> dsapresponse = dsapExternalService
.authenticate()
.handleRequestHeader(requestHeader -> {
requestHeader.withHeader("Authorization","Basic mncndsjna");
System.out.println("My Headers>>>>>>>> " + requestHeader);
return requestHeader;
})
.handleResponseHeader((responseHeader,b) -> {
System.out.println("RESPonse Header >>>>>>> : "+responseHeader);
return b;
})
.invoke(dsapWSRequest);
return dsapresponse;
}
In the above code header authorization is not set in the request. I am not getting this header in the echo which is mapped correctly in my POJO.
here is the complete code from my GitHub
https://github.com/sourabhsar/Lagom-Unmanaged-Service-Demo/tree/poc/lagom-request-response
I followed the steps mentioned here:
https://groups.google.com/forum/#!topic/lagom-framework/yvKmqvtZWFs
and also followed few other blogs/articles.
However so far I haven't found any blog which they are sending request to unmanaged external service with custom header. I'm not sure whats wrong in my code.
requestHeader.withHeader returns a new object with the added header, but the code you have written returns the original requestHeader object. In general, many Lagom APIs follow a principle of using immutable objects, with methods that return a new, modified instance, rather than changing the instance the method is called on.
Try this:
.handleRequestHeader(requestHeader -> {
RequestHeader modifiedRequestHeader =
requestHeader.withHeader("Authorization","Basic mncndsjna");
System.out.println("My Headers>>>>>>>> " + modifiedRequestHeader);
return modifiedRequestHeader;
})

Using vertx.io web client with no success

I am studying vertx.io web client and I am already blocked doing a simple get... Uff. Here is what I put together (I am very new at vertx.io):
private void getUserEmail(String accessToken, Handler<AsyncResult<String>> handler) {
String url = "https://graph.facebook.com/me";
HttpRequest<JsonObject> req = webClient.get(url).as(BodyCodec.jsonObject());
req.addQueryParam("access_token", accessToken);
req.addQueryParam("fields", "name,email");
MultiMap headers = req.headers();
headers.set("Accept", "application/json");
req.send(h -> {
if (h.succeeded()) {
log.info(h.result().toString());
handler.handle(new FutureFactoryImpl().succeededFuture(h.result().bodyAsString()));
} else {
log.error(h.cause());
handler.handle(new FutureFactoryImpl().failedFuture(h.cause()));
}
});
}
I think it should be enought but instead it's not. When I send request I get this error back:
io.vertx.core.json.DecodeException: Failed to decode: Unrecognized token 'Not': was expecting 'null', 'true', 'false' or NaN
at [Source: Not Found; line: 1, column: 4]
Of course if I do the same get by browser I get the expected data. I read the tutorial and examined the examples, what am I missing?
You're receiving a 404 error with the body: Not Found and the codec tries to parse it as JSON and fails. You need to verify if the request you're sending is correct.

In Java, how to set the header of a Restlet Response?

I can't seem to figure out how to add headers to my restlet response. When I look at the available methods in the Response object, all I see is setStatus, setEntity, and setAttributes but none of these tell me how to set custom http headers on the response.
For example, I have a GET call the returns something like the following:
HTTP/1.1 200 OK
Content-Type: text/json
Content-Length: 123
Some-Header: the value
Some-Other-Header: another value
{
id: 111,
value: "some value this could be anything",
diagnosis: {
start: 12552255,
end: 12552261,
key: "ABC123E11",
source: "S1",
}
}
Whatever it maybe. In the handleGet method, I handle it like so:
final MediaType textJsonType = new MediaType("text/json");
#Override
public void handleGet() {
log.debug("Handling GET...");
final Response res = this.getResponse();
try {
final MyObject doc = this.getObj("hello", 1, "ABC123E11", "S1");
final String docStr = doc.toString();
res.setStatus(Status.SUCCESS_OK);
res.setEntity(docStr, textJsonType);
// need to set Some-header, and Some-other-header here!
}
catch(Throwable t) {
res.setStatus(Status.SERVER_ERROR_INTERNAL);
res.setEntity(new TextRepresentation(t.toString()));
}
}
Because Restlet is more about the REST architectural principles than HTTP, it tries to be protocol agnostic and doesn't expose the HTTP headers directly. However, they are stored in the org.restlet.http.headers attribute of the response (as a Form). Note that you can only set custom headers this way, not standard ones (these are handled directly by the framework, e.g. Content-Type depends on the Representation's MediaType).
See this for an example:
http://blog.arc90.com/2008/09/15/custom-http-response-headers-with-restlet/ (link content also available from the Internet Archive Wayback Machine).

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