LinkedIn API Authentication using Java

Question

I am new to Linked In API for authentication. I went the API document provided by LinkedIn. It has samples for RUBY,PYTHON and PHP. But i am asked to achieve the same using Java

Answer 1

I hope this will work for you... i use spring framework

package yraunaj.controller;

import org.json.JSONException;
import org.json.JSONObject;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.client.RestTemplate;

@Controller
public class HomeController {

    //get client id and client Secret by creating a app in 
    //https://www.linkedin.com developers
    //and set your redirect url
    public String clientId="**********";
    public String clientSecret="***********";
    public String redirectUrl="http://localhost:8080/yraunaj/home"; 

    //create button on your page and hit this get request
    @GetMapping("/authorization")
    public String authorization() {
        String authorizationUri="https://www.linkedin.com/oauth/v2/authorization?response_type=code&client_id="+clientId+"&redirect_uri="+redirectUrl+"&state=asasasasasas&scope=r_basicprofile%20r_emailaddress";
        return "redirect:" + authorizationUri;
    }

    //after login in your linkedin account your app will hit this get request
    @GetMapping("/home")

    //now store your authorization code
    public String home(@RequestParam("code") String authorizationCode) throws JSONException {

        //to trade your authorization code for access token
        String accessTokenUri ="https://www.linkedin.com/oauth/v2/accessToken?grant_type=authorization_code&code="+authorizationCode+"&redirect_uri="+redirectUrl+"&client_id="+clientId+"&client_secret="+clientSecret+"";

        // linkedin api to get linkedidn profile detail
        String linedkinDetailUri = "https://api.linkedin.com/v1/people/~:(id,first-name,email-address,last-name,headline,picture-url,industry,summary)?format=json";

        //store your access token
        RestTemplate restTemplate = new RestTemplate();
        String accessTokenRequest = restTemplate.getForObject(accessTokenUri, String.class);
        JSONObject jsonObjOfAccessToken = new JSONObject(accessTokenRequest);
        String accessToken = jsonObjOfAccessToken.get("access_token").toString();

        //trade your access token
        HttpHeaders headers = new HttpHeaders();
        headers.add("Authorization", "Bearer " +accessToken);
        HttpEntity entity = new HttpEntity("parameters", headers);
        ResponseEntity linkedinDetailRequest = restTemplate.exchange(linedkinDetailUri, HttpMethod.GET, entity, String.class);
        //store json data
        JSONObject jsonObjOfLinkedinDetail = new JSONObject(linkedinDetailRequest.getBody());
        //print json data
        System.out.println(jsonObjOfLinkedinDetail);

        return "home";
    }
}