attachment support

[kleinmantara]

Code example for the PushoverRestClient class with the dependencies to httpmime.

	private static final ContentType plainUTF = ContentType.create("text/plain", MIME.UTF8_CHARSET);
	
	public Status pushMessage(PushoverMessage msg) throws PushoverException {
		final MultipartEntityBuilder builder = MultipartEntityBuilder.create();
		builder.addTextBody("token", msg.getApiToken(), plainUTF);
		builder.addTextBody("user", msg.getUserId(), plainUTF);
		builder.addTextBody("message", msg.getMessage(), plainUTF);

		addBodyIfNotNull(builder, "title", msg.getTitle());

		addBodyIfNotNull(builder, "url", msg.getUrl());
		addBodyIfNotNull(builder, "url_title", msg.getTitle());

		addBodyIfNotNull(builder, "device", msg.getDevice());
		addBodyIfNotNull(builder, "timestamp", "" + msg.getTimestamp());
		addBodyIfNotNull(builder, "sound", msg.getSound());
		addBodyIfNotNull(builder, "html", msg.isHtml() ? "1" : "0");

		if (!MessagePriority.NORMAL.equals(msg.getPriority())) {
			addBodyIfNotNull(builder, "priority", "" + msg.getPriority());
		}

		if (msg.getFile != null) {
			builder.addBinaryBody("attachment", msg.getFile().getStream(), msg.getFile().getContentType(),
					msg.getFile().getName());
		}

		HttpEntity multipart = builder.build();
		HttpPost post = new HttpPost(PUSH_MESSAGE_URL);
		post.setEntity(multipart);

		try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
			HttpResponse response = httpClient.execute(post);
			return PushoverResponseFactory.createStatus(response);
		} catch (Exception e) {
			throw new PushoverException(e.getMessage(), e.getCause());
		}
	}
	private void addBodyIfNotNull(MultipartEntityBuilder builder, String name, String value) {
		builder.addTextBody(name, value, plainUTF);
	}