# Yahoo Dsp API

# 產生Access token的流程

必要條件，要先有clientID clientSecret

參考文件

https://developer.yahooinc.com/identity/guide/enhanced-attribution/authentication/

must change scope "upload" as "dsp-api-access"
must change realm "aaca" as "dsp"

you can see scope and realm line 27 28

Java
package sample.aaca;

import com.google.gson.Gson;

import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import org.apache.http.HttpResponse;
import org.apache.http.client.config.CookieSpecs;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;

public class JavaSample {

    private static String oAuthURL = "https://id.b2b.yahooinc.com/identity/oauth2/access_token";
    private static String scope = "upload";
    private static String realm = "aaca";
    private String clientId = "//Insert ClientId here";
    private String clientSecret = "//Insert ClientSecret here";

    public static final long ACCESS_TOKEN_TTL = 600000;

    private String generateJsonWebToken() throws UnsupportedEncodingException {
        final HashMap<String, Object> claims = new HashMap<>();
        long nowMillis = System.currentTimeMillis();
        long expMillis = nowMillis + ACCESS_TOKEN_TTL;

        claims.put("iss", clientId);
        claims.put("sub", clientId);
        claims.put("aud", oAuthURL + "?realm=" + realm);
        claims.put("exp", expMillis / 1000);
        claims.put("iat", nowMillis / 1000);

        JwtBuilder jwtBuilder = Jwts.builder().setClaims(claims);

        return jwtBuilder.signWith(SignatureAlgorithm.HS256, clientSecret.getBytes("UTF-8")).compact();
    }

    private Response getTokenFromAuthServer(String assertion) throws IOException {
        Response response = null;

        try (CloseableHttpClient httpClient = HttpClientBuilder.create()
                .setDefaultRequestConfig(RequestConfig.custom().setCookieSpec(CookieSpecs.STANDARD).build()).build()) {
            StringBuilder payload = new StringBuilder().append("scope=").append(scope).append("&grant_type=")
                    .append("client_credentials").append("&client_assertion_type=")
                    .append("urn:ietf:params:oauth:client-assertion-type:jwt-bearer").append("&realm=").append(realm)
                    .append("&client_assertion=").append(assertion);

            HttpPost request = new HttpPost(oAuthURL);

            StringEntity body = new StringEntity(payload.toString(), ContentType.APPLICATION_FORM_URLENCODED);
            request.setEntity(body);
            request.addHeader("Accept", ContentType.APPLICATION_JSON.toString());

            System.out.println("Starting token request..........");
            HttpResponse result = httpClient.execute(request);

            System.out.println("Token request completed.......... "  +
                    result.getStatusLine().getStatusCode() + " " +
                    result.getStatusLine().getReasonPhrase());

            String json = EntityUtils.toString(result.getEntity(), "UTF-8");

            Gson gson = new Gson();
            response = gson.fromJson(json, Response.class);
        }
        return response;
    }

    /**
     * Get token from server.
     * @return token generated.
     * @throws Exception Throws exception if connection issues or encryption issues.
     */
    public String getToken() throws Exception {

        String assertion = generateJsonWebToken();

        Response response = getTokenFromAuthServer(assertion);

        String token = response.getAccessToken();

        return token;
    }

    /**
     * Helper class representing the json response from the IDB2B server
     */
    public static class Response {

        /**
         * String with token value received from
         * the IDB2B server
         */
        private String access_token;

        public Response() {}

        public Response(String access_token) {
            this.access_token = access_token;
        }

        public void setAccessToken(String access_token) {
            this.access_token = access_token;
        }

        public String getAccessToken() {
            return access_token;
        }
    }

    public static void main(String[] args) {

        JavaSample tokenGenerator = new JavaSample();

        String assertion;
        Response response;
            try {
              assertion = tokenGenerator.generateJsonWebToken();
              response = tokenGenerator.getTokenFromAuthServer(assertion);
                   System.out.println(response.getAccessToken());
        } catch (Exception e) {
              System.out.println("Exception occured..." + e.getMessage());
        }
    }
}

when you get the access token which print by main

 response = tokenGenerator.getTokenFromAuthServer(assertion);
                   System.out.println(response.getAccessToken());

## Step two

Get All AdvertiserIDs

https://dspapi.admanagerplus.yahoo.com/traffic/advertisers

-Header "X-Auth-Method: OAuth2" \
-Header "X-Auth-Token: accesstoken"

the accesstoken is something like this
:3f94eb47-a295-4977-a375-e27bea5c828b