Sign in with twitter using Twitter4j

                Day by day, social networking sites usage is becoming more. The web sites or the mobile apps are leveraging the social networking sites sign-in functionality to log in to their systems. In this article, we will see ‘how to set up twitter sign in for applications’ using twitter-4j by following the below steps.

Step 1: Create an application in https://dev.twitter.com/ by proving the application name, description, website URL and the callback URL(see the below screenshot). The callback URL is required to redirect the application, once the authentication is successful with Twitter.

Step 2: After creating the application, go to the application and change the settings(choose the “Access” and check “Allow this application to use the sign in with twitter option).

Step 3: Go to the application and collect the “Consumer key” and “Consumer secret“.

Step 4: Download the twitter4j distribution from http://twitter4j.org/en/ and put twitter4j-core-3.0.3.jar in the class-path.

Step 5: Write a Servlet or JSP to use as part of “Callback URL“. In this example, we will go with JSP(In the step1 screenshot, you can see the callback URL pointing to the same JSP).

function closeWindow(){
 

 

 self.close();
 }

Step 6: Write a Servlet called “TwitterSigninServlet”. This Servlet will get called when the user clicks on the  button. The Servlet code is given below,

package org.smarttechie.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import twitter4j.auth.RequestToken;

/**
* Servlet implementation class TwitterSigninServlet
*/
public class TwitterSigninServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public TwitterSigninServlet() {
 super();
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 try {
 Twitter twitter = new TwitterFactory().getInstance();
 RequestToken requestToken;
 request.getSession().setAttribute("twitter", twitter);
 twitter.setOAuthConsumer("", "");
 requestToken = twitter.getOAuthRequestToken("http://127.0.0.1:8080/Twitter-Sign-In-Web/views/redirect.jsp");
 String authURL = requestToken.getAuthenticationURL();
 request.getSession().setAttribute("requestToken", requestToken);
 response.sendRedirect(authURL);
 } catch (TwitterException  twitterException) {
 twitterException.printStackTrace();
 }
 }
}

Step 7: Write a JSP by putting “Sign in with Twitter” image. When the user clicks that image, we will call /signin Servlet(Created in Step6).

The sample twitter login testing



<a href="loginTwitter()"><img alt="twitter login" src="images/sign-in-with-twitter-gray.png" /></a>

In the above JSP, we have included a JS file called “twitter-login.js”. The code is given below.

var width = 820;
var height= 580;
var left = (screen.width/2)-(width/2);
function loginTwitter() {
 window.open("http://127.0.0.1:8080/Twitter-Sign-In-Web/signin",
 "mywindow","menubar=0,resizable=0,scrollbars=no,width="+width+",height="+height+",status=0,toolbar=0,left="+left+",top=120");
}

Once the user clicks on “Sign in with Twitter”, the Twitter Sign in prompt will appear. Once the user gets authorized with Twitter, the request will redirect to the “Callback URL“. Inside the “Callback URL”, we can get the authorized Twitter user id. Based on that, we can get the entire user object(look at Step5).

The source code available here.

About Siva Prasad Rao Janapati

Siva Janapati is an Architect with experience in building Cloud Native Microservices architectures, Reactive Systems, Large scale distributed systems, and Serverless Systems. Siva has hands-on in architecture, design, and implementation of scalable systems using Cloud, Java, Go lang, Apache Kafka, Apache Solr, Spring, Spring Boot, Lightbend reactive tech stack, APIGEE edge & on-premise and other open-source, proprietary technologies. Expertise working with and building RESTful, GraphQL APIs. He has successfully delivered multiple applications in retail, telco, and financial services domains. He manages the GitHub(https://github.com/2013techsmarts) where he put the source code of his work related to his blog posts.