title: Optimising multiple Java array additions
body: <p>I have the following code</p>
  
  <pre><code>JsonObject domainsObject = new JsonParser().parse(json).getAsJsonObject().get("data").getAsJsonObject();
          this.domain = domainsObject.get("main_domain").getAsString();
  
          this.domains.add(this.domain);
  
          for(JsonElement domain : domainsObject.get("addon_domains").getAsJsonArray()) {
              this.domains.add(domain.getAsString());
          }
  
          for(JsonElement domain : domainsObject.get("parked_domains").getAsJsonArray()) {
              this.domains.add(domain.getAsString());
          }
  
          for(JsonElement domain : domainsObject.get("sub_domains").getAsJsonArray()) {
              this.domains.add(domain.getAsString());
          }
  </code></pre>
  
  <p>However I want to optimise it properly because it seems like there will be a way to do this without needing to oppose DRY.</p>
  
  <p>Is there a way to squash the 3 separate arrays and the lone string all into one array without looping through each one manually?</p>