How to Access Adobe Sign API for Document Signing in Java

Get the Access Token

• Adobe Sign API requires OAuth-based authentication. Once you've registered your application and received your necessary credentials, you must obtain an access token.

 

• Use Adobe’s Authorization Code Grant to get a refresh token. You will first direct the user to Adobe’s authorization URL with your client ID, prompting them to authorize your application.

 

• After user authorization, Adobe redirects to your specified redirect URL with an authorization code. You will exchange this code for a refresh token.

 

• Use the refresh token to obtain an access token, which is necessary for making API requests.

Set Up Dependencies

• Use a library like Apache HttpComponents for handling HTTP requests in your Java application. Add relevant dependencies to your `pom.xml` if you're using Maven.

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>

Create a Java Client for Adobe Sign API

• Create a simple Java client to interact with Adobe Sign API. You will need to set the `Authorization` header with the Bearer token.

 

• You can use the `HttpClient` from Apache HttpComponents to make requests. Below is an example of how to create a document signing request.

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class AdobeSignClient {

    private static final String ACCESS_TOKEN = "your_access_token";
    private static final String API_URL = "https://api.adobesign.com/api/rest/v6/agreements";

    public void sendAgreement() throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            HttpPost postRequest = new HttpPost(API_URL);
            postRequest.addHeader("Authorization", "Bearer " + ACCESS_TOKEN);
            postRequest.addHeader("Content-Type", "application/json");

            String jsonPayload = "{\"fileInfos\": [{\"documentURL\": {\"url\": \"https://example.com/sample.pdf\"}}], \"name\": \"Sample Agreement\", \"participantSetsInfo\": [{\"memberInfos\": [{\"email\": \"example@example.com\"}], \"order\": 1, \"role\": \"SIGNER\"}], \"signatureType\": \"ESIGN\"}";

            StringEntity input = new StringEntity(jsonPayload);
            postRequest.setEntity(input);

            HttpResponse response = httpClient.execute(postRequest);
            String responseString = EntityUtils.toString(response.getEntity(), "UTF-8");
            System.out.println(responseString);
        } finally {
            httpClient.close();
        }
    }
}

Make API Calls

• Using the Java client created, you can now call Adobe Sign API methods like sending an agreement for signing, checking agreement status, or updating agreement details.

 

• The API responds with JSON, which you must parse to handle in your application. Consider using a library like Jackson or Gson for this purpose.

Error Handling and Logging

• Keep in mind error handling, as network issues or authorization errors might occur. Implement proper exception handling to manage HttpClient’s response.

 

• Logging is key for monitoring interactions with Adobe Sign API. Use a logging library like SLF4J or Log4j for effective logging.

Refreshing Access Tokens

• Since access tokens expire, ensure your application can automatically request a new access token using the refresh token.

 

• Store refresh tokens securely and renew the access token whenever you receive a 401 Unauthorized error from Adobe Sign API.