Added sendAudio support to AbsSender

Close #2

src/main/java/org/telegram/telegrambots/api/methods/SendAudio.java

@@ -51,11 +51,22 @@ public class SendAudio {
         return audio;
     }
 
+    /**
+     * Use this method to set the audio to an audio existing in Telegram system
+     * @param audio File_id of the audio to send
+     *
+     * @note The file_id must have already been received or sent by your bot
+     */
     public void setAudio(String audio) {
         this.audio = audio;
         this.isNewAudio = false;
     }
 
+    /**
+     * Use this method to set the audio to a new file
+     * @param audio Path to the new file in your server
+     * @param audioName Name of the file itself
+     */
     public void setNewAudio(String audio, String audioName) {
         this.audio = audio;
         this.isNewAudio = true;

src/main/java/org/telegram/telegrambots/bots/AbsSender.java

@@ -35,12 +35,16 @@ import java.util.concurrent.Executors;
 /**
  * @author Ruben Bermudez
  * @version 1.0
- * @brief TODO
+ * @brief Implementation of all the methods needed to interact with Telegram Servers
  * @date 14 of January of 2016
  */
 public abstract class AbsSender {
     private final ExecutorService exe = Executors.newSingleThreadExecutor();
 
+    /**
+     * Returns the token of the bot to be able to perform Telegram Api Requests
+     * @return Token of the bot
+     */
     public abstract String getBotToken();
 
     public Message sendMessage(SendMessage sendMessage) throws TelegramApiException {
@@ -390,6 +394,73 @@ public abstract class AbsSender {
         return new Message(jsonObject);
     }
 
+    /**
+     * Sends a file using Send Audio method (https://core.telegram.org/bots/api#sendaudio)
+     * @param sendAudio Information to send
+     * @return If success, the sent Message is returned
+     * @throws TelegramApiException If there is any error sending the audio
+     */
+    public Message sendAudio(SendAudio sendAudio) throws TelegramApiException {
+        String responseContent;
+
+        try {
+            CloseableHttpClient httpClient = HttpClients.createDefault();
+            String url = getBaseUrl() + SendAudio.PATH;
+            HttpPost httppost = new HttpPost(url);
+
+            if (sendAudio.isNewAudio()) {
+                MultipartEntityBuilder builder = MultipartEntityBuilder.create();
+                builder.addTextBody(SendAudio.CHATID_FIELD, sendAudio.getChatId());
+                builder.addBinaryBody(SendAudio.AUDIO_FIELD, new java.io.File(sendAudio.getAudio()), ContentType.APPLICATION_OCTET_STREAM, sendAudio.getAudioName());
+                if (sendAudio.getReplayMarkup() != null) {
+                    builder.addTextBody(SendAudio.REPLYMARKUP_FIELD, sendAudio.getReplayMarkup().toJson().toString());
+                }
+                if (sendAudio.getReplayToMessageId() != null) {
+                    builder.addTextBody(SendAudio.REPLYTOMESSAGEID_FIELD, sendAudio.getReplayToMessageId().toString());
+                }
+                if (sendAudio.getPerformer() != null) {
+                    builder.addTextBody(SendAudio.PERFOMER_FIELD, sendAudio.getPerformer());
+                }
+                if (sendAudio.getTitle() != null) {
+                    builder.addTextBody(SendAudio.TITLE_FIELD, sendAudio.getTitle());
+                }
+                HttpEntity multipart = builder.build();
+                httppost.setEntity(multipart);
+            } else {
+                List<NameValuePair> nameValuePairs = new ArrayList<>();
+                nameValuePairs.add(new BasicNameValuePair(SendAudio.CHATID_FIELD, sendAudio.getChatId()));
+                nameValuePairs.add(new BasicNameValuePair(SendAudio.AUDIO_FIELD, sendAudio.getAudio()));
+                if (sendAudio.getReplayMarkup() != null) {
+                    nameValuePairs.add(new BasicNameValuePair(SendAudio.REPLYMARKUP_FIELD, sendAudio.getReplayMarkup().toString()));
+                }
+                if (sendAudio.getReplayToMessageId() != null) {
+                    nameValuePairs.add(new BasicNameValuePair(SendAudio.REPLYTOMESSAGEID_FIELD, sendAudio.getReplayToMessageId().toString()));
+                }
+                if (sendAudio.getPerformer() != null) {
+                    nameValuePairs.add(new BasicNameValuePair(SendAudio.PERFOMER_FIELD, sendAudio.getPerformer()));
+                }
+                if (sendAudio.getTitle() != null) {
+                    nameValuePairs.add(new BasicNameValuePair(SendAudio.TITLE_FIELD, sendAudio.getTitle()));
+                }
+                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));
+            }
+
+            CloseableHttpResponse response = httpClient.execute(httppost);
+            HttpEntity ht = response.getEntity();
+            BufferedHttpEntity buf = new BufferedHttpEntity(ht);
+            responseContent = EntityUtils.toString(buf, "UTF-8");
+        } catch (IOException e) {
+            throw new TelegramApiException("Unable to send sticker", e);
+        }
+
+        JSONObject jsonObject = new JSONObject(responseContent);
+        if (!jsonObject.getBoolean("ok")) {
+            throw new TelegramApiException("Error at sendAudio", jsonObject.getString("description"));
+        }
+
+        return new Message(jsonObject);
+    }
+
     private void sendApiMethodAsync(BotApiMethod method, SentCallback callback) {
         exe.submit(() -> {
             try {