Postmarkup email service

public class PostmarkMailSender implements MailSender{

    private static Logger logger = Logger.getLogger("com.postmark");

    private String serverToken;
    private static Gson gson;

    static {
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder.disableHtmlEscaping();
        SimpleMailMessage src=new SimpleMailMessage();
        String [] arr={"",""};
        src.setTo(arr);
        System.out.println(src.getTo());

        gsonBuilder.registerTypeAdapter(SimpleMailMessage.class, new SimpleMailMessageAdapter());
        gsonBuilder.registerTypeAdapter(PostmarkMessage.class, new SimpleMailMessageAdapter());
        gsonBuilder.registerTypeAdapter(DateTime.class, new DateTimeTypeAdapter());
        gson = gsonBuilder.create();
    }


    /**
     * Initializes a new instance of the PostmarkClient class.
     * <p/>
     * If you do not have a server token you can request one by signing up to
     * use Postmark: https://postmarkapp.com.
     *
     * @param serverToken the postmark server token
     */
    public PostmarkMailSender(String serverToken) {
        this.serverToken = serverToken;
    }

    @Override
    public void send(SimpleMailMessage message) throws MailException {

        System.out.println("1*************************************************");

        HttpClient httpClient = new DefaultHttpClient();
        PostmarkResponse theResponse = new PostmarkResponse();
        System.out.println("2***************************************");

        try {
            System.out.println("3********************************************");
            // Create post request to Postmark API endpoint
            HttpPost method = new HttpPost("https://api.postmarkapp.com/email");

            // Add standard headers required by Postmark
            method.addHeader("Accept",            "application/json");
            method.addHeader("Content-Type",    "application/json; charset=utf-8");
            method.addHeader("X-Postmark-Server-Token", serverToken);
            method.addHeader("User-Agent",        "Postmark-Java");

            // Convert the message into JSON content
            String messageContents = UnicodeEscapeFilterWriter.escape(gson.toJson(message));
            logger.log(Level.FINER, "Message contents: " + messageContents);

            // Add JSON as payload to post request
            StringEntity payload = new StringEntity(messageContents);
            payload.setContentEncoding(HTTP.UTF_8);
            method.setEntity(payload);
            System.out.println("4********************************************");
            ResponseHandler<String> responseHandler = new BasicResponseHandler();
            try {
                System.out.println("5*************************************************");

                String response = httpClient.execute(method, responseHandler);
                logger.log(Level.FINER, "Message response: " + response);
                theResponse = gson.fromJson(response, PostmarkResponse.class);
                theResponse.status = PostmarkResponseStatus.SUCCESS;
            } catch (HttpResponseException hre) {
                switch(hre.getStatusCode()) {
                    case 401:
                    case 422:
                        logger.log(Level.SEVERE, "There was a problem with the email: " + hre.getMessage());
                        theResponse.setMessage(hre.getMessage());
                        theResponse.status = PostmarkResponseStatus.USERERROR;
                        throw new MailSendException("Postmark returned: "+theResponse);
                    case 500:
                        logger.log(Level.SEVERE, "There has been an error sending your email: " + hre.getMessage());
                        theResponse.setMessage(hre.getMessage());
                        theResponse.status = PostmarkResponseStatus.SERVERERROR;
                        throw new MailSendException("Postmark returned: "+theResponse);
                    default:
                        logger.log(Level.SEVERE, "There has been an unknow error sending your email: " + hre.getMessage());
                        theResponse.status = PostmarkResponseStatus.UNKNOWN;
                        theResponse.setMessage(hre.getMessage());
                        throw new MailSendException("Postmark returned: "+theResponse);


                }
            }

        } catch (Exception e) {
            logger.log(Level.SEVERE, "There has been an error sending email: " + e.getMessage());
            throw new MailSendException("There has been an error sending email", e);

        } finally {
            httpClient.getConnectionManager().shutdown();
        }


    }

    @Override
    public void send(SimpleMailMessage[] simpleMessages) throws MailException {
        System.out.println("7*************************************************");
        ///FIXME default naive, non-optimal implementation (sequentially opens simpleMessages.length HTTP connections...)
        Map<Object, Exception> failedMessages = new LinkedHashMap<Object, Exception>();
        for(SimpleMailMessage simpleMessage: simpleMessages) {
            try {
                System.out.println("8*************************************************");
                send(simpleMessage);
            } catch (MailException mex) {
                failedMessages.put(simpleMessage, mex);
            }
        }
        if(! failedMessages.isEmpty())
            throw new MailSendException(failedMessages);
    }



    //  PostMark Reponse utilities

    /**
     * Possible outcomes of a Response from the Postmark server
     */
    static enum PostmarkResponseStatus {
        UNKNOWN, SUCCESS, USERERROR, SERVERERROR
    }

    /**
     * Response from the Postmark server
     */
    static class PostmarkResponse {
        @Override
        public String toString() {
            return "PostmarkResponse [errorCode=" + errorCode + ", message="
                    + message + ", status=" + status + ", submittedAt="
                    + submittedAt + ", to=" + to + "]";
        }

        /** The status outcome of the response. */
        @SerializedName("Status")
        public PostmarkResponseStatus status;

        /** The message from the API. In the event of an error, this message may contain helpful text. */
        @SerializedName("Message")
        public String message;

        /** The time the request was received by Postmark. */
        @SerializedName("SubmittedAt")
        public DateTime submittedAt;

        /** The recipient of the submitted request. */
        @SerializedName("To")
        public String to;

        /** The error code returned from Postmark. This does not map to HTTP status codes. */
        @SerializedName("ErrorCode")
        public int errorCode;

        public PostmarkResponseStatus getStatus() {
            return status;
        }
        public void setStatus(PostmarkResponseStatus status) {
            this.status = status;
        }

        public String getMessage() {
            return message;
        }
        public void setMessage(String message) {
            this.message = message;
        }

        public DateTime getSubmittedAt() {
            return submittedAt;
        }
        public void setSubmittedAt(DateTime submittedAt) {
            this.submittedAt = submittedAt;
        }

        public String getTo() {
            return to;
        }
        public void setTo(String to) {
            this.to = to;
        }

        public int getErrorCode() {
            return errorCode;
        }
        public void setErrorCode(int errorCode) {
            this.errorCode = errorCode;
        }
    }



    //  GSON Serializers

    /**
     * Gson Serializer for Spring's SimpleMailMessage
     *
     * @see JsonSerializer
     * @see SimpleMailMessage
     */
    public static class SimpleMailMessageAdapter implements JsonSerializer<SimpleMailMessage> {

        @Override
        public JsonElement serialize(SimpleMailMessage src, Type typeOfSrc, JsonSerializationContext context) {
            System.out.println("9*************************************************");
            JsonObject jsonO = new JsonObject();
            if (src.getFrom() == null) {
                throw new MailParseException("You must specify a from address");
            }
            jsonO.addProperty("From", "support@pharmerz.in");
            if (src.getTo() == null) {
                throw new MailParseException("You must specify a to address");
            }
            String [] arrnew=src.getTo();

            jsonO.addProperty("To",arrnew[0]);
            if (src.getCc() != null) {
                jsonO.addProperty("Cc", "");
            }
            if (src.getBcc() != null) {
                jsonO.addProperty("Bcc", "");
            }
            if (src.getSubject() == null) {
                throw new MailParseException("You must specify a Subject field");
            }
            jsonO.addProperty("Subject",src.getSubject());

            if (src instanceof PostmarkMessage) {
                PostmarkMessage postmarkSrc = (PostmarkMessage) src;

                if (postmarkSrc.getTag() != null) {
                    jsonO.addProperty("Tag", postmarkSrc.getTag());
                }

                if (postmarkSrc.getHtmlBody() != null) {
                    jsonO.addProperty("HtmlBody", ((PostmarkMessage) src).getHtmlBody());
                }

                if (src.getText() == null && postmarkSrc.getHtmlBody() == null) {
                    throw new MailParseException("You must specify a Text field !");
                }

            } else  if (src.getText() == null) {
                throw new MailParseException("You must specify a Text field");
            }

            jsonO.addProperty("TextBody", "test mail from postmarkmailsender");

            if (src.getReplyTo() != null) {
                jsonO.addProperty("ReplyTo", "kk");
            }

            return jsonO;
        }

        private static String mergeMailAddresses(String[] addresses) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < addresses.length; i++) {
                sb.append(addresses[i]);
                if (i < addresses.length - 1) {
                    sb.append(",");
                }
            }
            return sb.toString();
        }

    }

    /**
     * Gson Serializer for Joda DateTime
     *
     * @see JsonSerializer
     * @see DateTime
     */
    static class DateTimeTypeAdapter implements JsonSerializer<DateTime>, JsonDeserializer<DateTime> {
        @Override
        public JsonElement serialize(DateTime src, Type typeOfSrc, JsonSerializationContext context) {
            return new JsonPrimitive(src.toString());
        }

        @Override
        public DateTime deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
            return new DateTime(json.getAsJsonPrimitive().getAsString());
        }
    }

public class PostmarkMessage extends SimpleMailMessage  {


    private String tag;

    private String htmlBody;

    public void setTag(String tag) {
        this.tag = tag;
    }

    public String getTag() {
        return tag;
    }

    public String getHtmlBody() {
        return htmlBody;
    }

    public void setHtmlBody(String htmlBody) {
        this.htmlBody = htmlBody;
    }
}

public class UnicodeEscapeFilterWriter extends FilterWriter{


    protected UnicodeEscapeFilterWriter(Writer out) {
        super(out);
    }

    private static char[] prefix = { '\\', 'u', '0', '0', '0' };


    @Override
    public void write(char[] cbuf, int off, int len) throws IOException {
        for (int i = 0; i < len; i++) {
            if ((cbuf[i] > '\u007f')) {
                String hx = Integer.toHexString(cbuf[i]);
                out.write(prefix, 0, 6 - hx.length());
                out.write(hx);
            } else
                out.write(cbuf[i]);
        }
    }

    @Override
    public void write(int c) throws IOException {
        write(new char[] {(char)c}, 0, 1);
    }

    @Override
    public void write(String str, int off, int len) throws IOException {
        write(str.toCharArray(), off, len);
    }


    /**
     * Escapes <tt>str</tt> using this Filter.
     * <p>
     * Default estimate for non-ASCII chars ratio is 3%
     *
     * @param str the original String
     * @return the escaped String
     * @throws IOException
     */
    public static String escape(String str) throws IOException {
        return escape(str, .03f);
    }

    /**
     * Escapes <tt>str</tt> using this Filter.
     *
     * @param str the original String
     * @param estimatedNonASCIIRatio an estimation of the ratio of non-ASCII chars in <tt>str</tt>.
     * It is used for the initial allocation size of the new char array.
     * @return the escaped String
     * @throws IOException
     */
    public static String escape(String str, float estimatedNonASCIIRatio) throws IOException {
        StringWriter out = new StringWriter(Math.round(str.length() * (1 + estimatedNonASCIIRatio * 5)));
        UnicodeEscapeFilterWriter fw = new UnicodeEscapeFilterWriter(out);
        fw.write(str);
        return out.toString();

    }
}

public class Email {


    public void SendMail(String TO, String SUBJECT, String HTMLBODY) {

        String TEST_API_KEY = "3b2e23b0-****-****-****-*********";

        String FROM = "support@pharmerz.in";
        PostmarkMailSender mailSender = new PostmarkMailSender(TEST_API_KEY);

        PostmarkMessage m = new PostmarkMessage();
        m.setFrom(FROM);
        m.setTo(TO);
        m.setSubject(SUBJECT);
        m.setHtmlBody(HTMLBODY);
        //m.setText(HTMLBODY);
        // m.setTag("test-utf8");
        mailSender.send(m);
    }

}