Develop Reference

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.

Synchronize REST endpoint to wait for 2 calls with same parameter

I am creating an application in which two players should have an opportunity to compete with each other in writing code.
For example, for now one player can initiate a session creation:
#PostMapping("/prepareSession")
public UUID prepareSession(#RequestParam("taskName") String taskName) {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
String currentPrincipalName = authentication.getName();
User playerOne = userService.findOne(currentPrincipalName);
Task task = taskService.findOne(taskName);
UUID sessionId = UUID.randomUUID();
sessionService.save(new Session(sessionId, playerOne, null, task));
return sessionId;
}
Then, this session id he needs to send to a player who he wants to compete.
And then second player inputs sessionId and gets a task description.
#GetMapping("/connect")
public Task connect(#RequestParam("sessionId") String sessionId) throws InterruptedException {
Session session = sessionService.findOne(sessionId);
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
String currentPrincipalName = authentication.getName();
User playerSecond = userService.findOne(currentPrincipalName);
session.setPlayerSecond(playerSecond);
sessionService.save(session);
return session.getTask();
}
I wonder how to make the rest endpoint to wait until both players with same sessionId calls it and then notify them with the task description.
I want them to write code within a one session, with a one code timer.
Please suggest how I should do that

What you are looking for can be achieve like this
You could use a DeferredResult result and store it in a map until a user with the same sessionId joins. Ex
Map<String, DeferredResult<ResponseEntity<?>>> unconnected = new HashMap<String, DeferredResult<ResponseEntity<?>>>();
User one would call the connect prepareSessionAPI to receive the sessionId
User one would then call the connect API. The connet api would store this request/defferred result in the hashmap until user 2 joins. Ex
DeferredResult<Task> unconnectedTask = new DeferredResult<Task>();
unconnected.put(sessionId, unconnectedTask);
Now, user one's request would be stored in an in memory map until user two joins
User one would send the sessionId to user two
User two would call the connect API. The connect API would look for the session in the HashMap, and if it exists, it would perform the operations needed, then set the result of the deferred result. Ex
DeferredResult<Task> unconnectedTask = unconnected.get(sessionId);
if(unconnectedTask != null) {
// Do work
unconnectedTask.setResult(task);
} else {
// This is user one's request
}
Please note, this is pseudo code.

put this code both of method,
please import spring transnational jar
#Transactional(propagation =Propagation.REQUIRED,isolation=Isolation.SERIALIZABLE,readOnly=false,transactionManager="transactionManager")
if any issue inform

Refreshing an Access Token for Client Credentials Flow

I was wondering what the best way is for me to refresh an access token that is obtained through the client credentials flow within OAuth 2.0. I've read over the spec, but I can't seem to be able to find an answer for my particular situation.
For my specific case, I am using the Spotify Web API for my Android app in order to search for content (tracks, albums, and/or artists). In order to perform a search, I need an access token. Since I'm not interested in a Spotify user's data, I can use the client credentials flow to obtain the access token, which is explain in Spotify's terms here.
Because the access token can eventually expire, I had to figure out a way to refresh it once expiration occurred. What I'm ultimately wondering is if my approach is valid and if there's any concern with how I've approached this.
First and foremost, I stored my access token within SharedPreferences. Within onCreate(), I have the following:
#Override
protected void onCreate(Bundle savedInstanceState) {
// A bunch of other stuff, views being initialized, etc.
mAccessToken = getAccessToken();
// If the access token is expired, then we will attempt to retrieve a new one
if (accessTokenExpired()) {
retrieveAccessToken();
}
}
I've defined accessTokenExpired() and retrieveAccessToken() as follows:
private boolean accessTokenExpired() {
// If mAccessToken hasn't yet been initialized, that means that we need to try to retrieve
// an access token. In this case, we will return true;
if (mAccessToken == null) {
return true;
}
SharedPreferences preferences = getPreferences(Context.MODE_PRIVATE);
long timeSaved = preferences.getLong(PREFERENCES_KEY_TOKEN_RESPONSE_TIME_SAVED, 0L);
long expiration = preferences.getLong(PREFERENCES_KEY_TOKEN_RESPONSE_EXPIRATION, 0L);
long now = System.currentTimeMillis()/1000;
long timePassed = Math.abs(now - timeSaved);
if (timePassed >= expiration) {
return true;
} else {
return false;
}
}
One thing worth noting about retrieveAccessToken() is that I'm using Retrofit for my HTTP request:
private void retrieveAccessToken() {
// First, we obtain an instance of SearchClient through our ClientGenerator class
mClient = ClientGenerator.createClient(SearchClient.class);
// We then obtain the client ID and client secret encoded in Base64.
String encodedString = encodeClientIDAndSecret();
// Finally, we initiate the HTTP request and hope to get the access token as a response
Call<TokenResponse> tokenResponseCall = mClient.getAccessToken(encodedString, "client_credentials");
tokenResponseCall.enqueue(new Callback<TokenResponse>() {
#Override
public void onResponse(Call<TokenResponse> call, Response<TokenResponse> response) {
Log.d(TAG, "on Response: response toString(): " + response.toString());
TokenResponse tokenResponse = null;
if (response.isSuccessful()) {
tokenResponse = response.body();
Log.d(TAG, tokenResponse.toString());
mAccessToken = tokenResponse.getAccessToken();
saveAccessToken(tokenResponse);
}
}
#Override
public void onFailure(Call<TokenResponse> call, Throwable t) {
Log.d(TAG, "onFailure: request toString():" + call.request().toString());
mAccessToken = "";
}
});
}
Finally, saveAccessToken(tokenResponse) is sort of the complement of accessTokenExpired(), where I'm saving the values from the token response into SharedPreferences rather than retrieving them.
Are there any concerns with how I'm doing this? I got the idea from this SO post and slightly modified it. Spotify doesn't provide a refresh token in their access token response. Therefore, I can't make use of it here to reduce the number of access token requests I make.
Any input on this would be greatly appreciated!

Two considerations are:
you probably want some error handling around the requests you make using the access token that can handle the token expiring and do retries. The two situations where this will help are
when the token expires between checking if it's valid and your usage of it
when in the cycle of check the token is valid -> make some requests with the token -> repeat, you spend over an hour using the token. Another way you can do it is to calculate now + expected_api_request_time > token_expiration_time where expected_api_request_time would be a constant you set, but I think handling token expiry as an exception is better practice (you probably want to be able to make retries anyway in cases of network instability).
you can perform the calculations to work out when the token expires either when you retrieve the timeSaved and expiration from your local storage, or just calculate the time the token will expire initially and save that. This is relatively minor, both this and the way you've done it are fine I think.

Passing phone input via Twilio

I'm working on a basic Twilio web application using Java and the Spark Java framework. I'm trying to have the user enter a number as input after the initial prompt through a Gather verb and then process that input. So far, I am able to call my Twilio number and it responds with the initial prompt, but after I enter a number it goes to /handle-number and crashes because the request did not contain any params and it can't find the "Digits" param (params is empty when I print it).
I have tried to mimic the API call via the Postman Chrome extension to debug it, but I get a 500 internal server error.
EDIT: Here is a screenshot of the postman request : Postman screenshot
I am new to Java web applications, HTTP requests, and Twilio, so I am unfamiliar with much of this. I have gone thought the twiml documentation and tutorials and tried to follow along but my I'm definitely missing something in my implementation.
How do I properly pass the phone input to the processNumber Route? Any help is appreciated!
App.java
import static spark.Spark.*;
public class App {
public static void main (String[] args){
post("/receive-call", ReceiveCall.call);
post("/handle-number", ReceiveCall.processNumber);
}
}
ReceiveCall.java
import com.twilio.twiml.voice.Gather;
import com.twilio.twiml.voice.Say;
import com.twilio.twiml.*;
import spark.Route;
public class ReceiveCall {
public static Route call = (request, response) -> {
Say sayMessage = new Say.Builder("Hello! Please enter a number as input. Enter # when finished.").build();
Gather input = new Gather.Builder().timeout(3).say(sayMessage).action("/handle-number").build();
VoiceResponse twiml = new VoiceResponse.Builder().gather(input).build();
System.out.println(response.body());
return twiml.toXml();
};
public static Route processNumber = ((request, response) -> {
String digit = request.params("Digits");
//CRASHES HERE BECAUSE digit IS NULL
int number = Integer.parseInt(digit);
Say message = process(number);
VoiceResponse twiml = new VoiceResponse.Builder().say(message).build();
return twiml.toXml();
});

The reason of "digit IS NULL" is: you are using request.params(...), which is for path parameter.
What is "path parameter"?
"path parameter" means passing parameter as part of URL path, especially in RESTful style request.
For example, if you want to send an HTTP GET request to retrieve a book by its ISBN, the request URL could be: /books/9787121022982 or /books/9787101054491, where the ISBN parameter is passed as part of URL path (9787121022982 and 9787101054491). In Spark framework, the corresponding Route code would be:
get("/books/:isbn", (request, response) -> {
return "Book ISBN is: " + request.params(":isbn");
});
What is "query parameter"?
"query parameter" means passing parameter as part of URL queries (entities after the ? character in URL).
Take the previous book ISBN case for example, if you want to pass ISBN as query parameter, the HTTP GET URL would be: /books?isbn=9787121022982, and the corresponding Spark Route code is:
get("/books", (request, response) -> {
return "Book ISBN is: " + request.queryParams("isbn");
});
What is the best practice to pass data in POST request?
In your case, the /handle-number route accept POST request. For HTTP POST request, it's not a good practice to pass data as parameter in URL. Instead, you need to pass data as request body, and get data from body in Spark code:
post("/handle-number", (request, response) -> {
String body = request.body();
// extract ISBN from request body string
});

Extracting the #Field parameter from retrofit with Node.js Express

I am trying to make an app in Android and have some problem. I have searched the web but I haven't found an obvious solution.
In my Android app I send a Post request for a login task using Retrofit.
#FormUrlEncoded
#POST("/login")
Call<Boolean> loginUser(#Field("username") String userName, #Field("password") String password);
My server is in Node.js with express and I don't know how to extract the username and password parameters.
my app.js file looks like this:
var http = require('http');
var express = require('express');
var bodyparser = require('body-parser');
var connection = require('./dbConnection');
var app = express();
require('./models')(app);
require('./controllers')(app);
require('./routes')(app);
app.use(bodyparser.urlencoded({extended: true}));
app.use(bodyparser.json());
connection.init();
var server = app.listen(3000, function() {
console.log('Server listening on port ' + server.address().port);
});
And my routes file for login looks like this:
var loginM = require('../models/login');
var loginC = require('../controllers/login');
module.exports = function(app) {
app.post('/login/', function(req, res, next) {
loginM.attemptLogin(req.body, res);
});
}
req.body does not seem to give me the #Field variables, I have tried req.headers and req.params as well with no success. Can someone explain how to extract them?
Much appreciated

On NodeJs side, or better: expressjs app side, you need to use a body-parser middleware, such as https://github.com/expressjs/body-parser
npm install body-parser --save
Since body-parser supports JSON as well as URL encoded input (which retrofit #Field generates) you need to add appropriate middleware functions to app:
var bodyParser = require('body-parser');
// parse JSON inputs
app.use(bodyParser.json());
// Also, parse URL encoded inputs
app.use(bodyParser.urlencoded());
// handle requests
app.post('/login/', function(req, res, next) {
loginM.attemptLogin(req.body, res);
});
Also, remember that you add body-parser middleware Before adding routes/controllers to the app. Because parser middleware should be executed before so that input is parsed by the time request handling logic is executed.
var app = express();
// first
app.use(bodyparser.urlencoded({extended: true}));
app.use(bodyparser.json());
// after
require('./models')(app);
require('./controllers')(app);
require('./routes')(app);