Creating anonymous snippets

We first need a web client object to issue HTTP requests to the Gist API:

  1. webClient = WebClient.create(vertx, new WebClientOptions()
  2.   .setSsl(true)
  3.   .setUserAgent("vert-x3"));
Tip
Since requests are made using HTTPS, we need to configure the web client with SSL support.
Tip
We override the default user agent with vert-x3 but you may opt to use your own value instead.

We then modify the web router configuration in the HttpServerVerticle class to add a new route for triggering backups:

  1. router.get("/backup").handler(this::backupHandler);

The code for this handler is the following:

  1. private void backupHandler(RoutingContext context) {
  2.   dbService.fetchAllPagesData(reply -> {
  3.     if (reply.succeeded()) {
  5.       JsonArray filesObject = new JsonArray();
  6.       JsonObject payload = new JsonObject() (1)
  7.         .put("files", filesObject)
  8.         .put("language", "plaintext")
  9.         .put("title", "vertx-wiki-backup")
  10.         .put("public", true);
  12.       reply
  13.         .result()
  14.         .forEach(page -> {
  15.           JsonObject fileObject = new JsonObject(); (2)
  16.           fileObject.put("name", page.getString("NAME"));
  17.           fileObject.put("content", page.getString("CONTENT"));
  18.           filesObject.add(fileObject);
  19.         });
  21.       webClient.post(443, "snippets.glot.io", "/snippets") (3)
  22.         .putHeader("Content-Type", "application/json")
  23.         .as(BodyCodec.jsonObject()) (4)
  24.         .sendJsonObject(payload, ar -> {  (5)
  25.           if (ar.succeeded()) {
  26.             HttpResponse<JsonObject> response = ar.result();
  27.             if (response.statusCode() == 200) {
  28.               String url = "https://glot.io/snippets/" + response.body().getString("id");
  29.               context.put("backup_gist_url", url);  (6)
  30.               indexHandler(context);
  31.             } else {
  32.               StringBuilder message = new StringBuilder()
  33.                 .append("Could not backup the wiki: ")
  34.                 .append(response.statusMessage());
  35.               JsonObject body = response.body();
  36.               if (body != null) {
  37.                 message.append(System.getProperty("line.separator"))
  38.                   .append(body.encodePrettily());
  39.               }
  40.               LOGGER.error(message.toString());
  41.               context.fail(502);
  42.             }
  43.           } else {
  44.             Throwable err = ar.cause();
  45.             LOGGER.error("HTTP Client error", err);
  46.             context.fail(err);
  47.           }
  48.       });
  50.     } else {
  51.       context.fail(reply.cause());
  52.     }
  53.   });
  54. }

  1. The snippet creation request payload is a JSON document as outlined in the service API documentation.

  2. Each file is an entry under the files object of the payload, with a title and content.

  3. The web client needs to issue a POST request on port 443 (HTTPS), and the path must be /snippets.

  4. The BodyCodec class provides a helper to specify that the response will be directly converted to a Vert.x JsonObject instance. It is also possible to use BodyCodec#json(Class<T>) and the JSON data will be mapped to a Java object of type T (this uses Jackson data mapping under the hood).

  5. sendJsonObject is a helper for triggering the HTTP request with a JSON payload.

  6. Upon success we can get the snippet identifier, and construct a URL to the user-friendly web representation.