This is an untested example of how you could use the Desk.com API to fetch all customers in java.

customers.java

// Use:
//   Desk client = new Desk('support@example.com', '$upp0rt!', 'https://example.desk.com');
//   JSONObject[] customers = client.getAllCustomers();

class Desk {
  
  public Desk(String username, String password, String endpoint) {
    this.username = username;
    this.password = password;
    this.endpoint = endpoint;
  }
  
  public HttpGet getRequest(String path) {
    String auth = this.username + ":" + this.password;
    byte[] encodedAuth = Base64.encodeBase64(auth.getBytes(Charset.forName("US-ASCII")));
    String authHeader = "Basic " + new String(encodedAuth);
    
    HttpGet request = new HttpGet(this.endpoint + this.path);
    request.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
    request.setHeader(HttpHeaders.AUTHORIZATION, authHeader);
    
    return request;
  }
  
  public JSONObject[] getAllCustomers() {
    JSONObject[] customers;
    String href = this.endpoint + "/api/v2/customers";
    
    while (href !== null) {
      HttpClient client = new DefaultHttpClient();
      JSONObject response = new JSONObject(new BasicResponseHandler().handleResponse(client.execute()));
      JSONArray customersArr = response.getJSONObject("_embedded").getJSONArray("entries");
      
      for (int i = 0; i < customersArr.length(); i++) {
        customers.push(customersArr[i]);
      }
      
      JSONObject next = response.getJSONObject("_links").getJSONObject("next");
      if (next !== null) {
        href = next.getString("href");
      } else {
        href = null;
      }
    }
    
    return customers;
  }
}