DesignDocument.txt

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Name :- Siddharth Nahar
Entry No :- 2016csb1043
Date :- 22/11/18

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* For Authorization of Email for Scopes :

	private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
	
		/*Get Client Credentials*/
		InputStream in = Authentication.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
		GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

		/*Build an Authorization request for permission according to Scopes*/
		GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
			HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
			.setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
			.setAccessType("offline")
			.build();

		/*Set the Reciever for most common port and return Credentials Object Created*/
		LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
		return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");

	}

	/*This Function returns the Gmail Service Object Requested by Reader and Writer*/
	public static Gmail serviceObject() throws IOException, GeneralSecurityException{

		/*Setting up Gmail Service Object with parameters specified*/
		final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
		Gmail service = new Gmail.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
		        .setApplicationName(APPLICATION_NAME)
		        .build();

		return service;
	}

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* For Creating Draft Message


	/*Create an Empty Message with filePath as subject*/
	public static MimeMessage createEmail(String subject, String body)throws MessagingException {

		/*Create Objects of class for MimeMessgae*/
		Properties props = new Properties();
		Session session = Session.getDefaultInstance(props, null);

		MimeMessage email = new MimeMessage(session);

		/*Set From Address as your gmail id and set subject*/
		email.setFrom(new InternetAddress("sid23nahar@gmail.com"));
		/*
		email.addRecipient(javax.mail.Message.RecipientType.TO,
			new InternetAddress("sid23nahar@gmail.com"));*/
		email.setSubject(subject);
		email.setText(body);

		return email;

	}

	/**
	* Create a message from an email.
	*
	* @param emailContent Email to be set to raw of message
	* @return a message containing a base64url encoded email
	* @throws IOException
	* @throws MessagingException
	*/
	public static Message createMessageWithEmail(MimeMessage emailContent) throws MessagingException, IOException {

		ByteArrayOutputStream buffer = new ByteArrayOutputStream();
		emailContent.writeTo(buffer);

		/*Encode message to raw wncoding and set to message*/
		byte[] bytes = buffer.toByteArray();
		String encodedEmail = Base64.encodeBase64URLSafeString(bytes);

		Message message = new Message();
		message.setRaw(encodedEmail);
		return message;

	}


	public void flush() throws IOException {
	//TODO: Implement proper logic

		try{
			/*Create new email,Messgae and Update the Previous Draft*/
			//System.out.println("This Data Will be Written : "+this.DataWritten);
			if(this.DataWritten.equals("") == false){ 

				String userId = "me";
				/*Get email and message part of that email to store as Draft*/
	    			MimeMessage email = Drafts.createEmail(filePath, this.DataWritten);
				Message updated = Drafts.createMessageWithEmail(email);

				/*Create new Draft and set message*/
				Draft draft = new Draft();
				draft.setMessage(updated);

				/*Create the draft*/
				draft = gmailService.users().drafts().create(userId, draft).execute();

			}else{

				//System.out.println("No Message Content to Write");
				return;
			}			

		}catch(MessagingException e){

			System.out.println(e.getMessage());

		}

		/*Empty the Buffer*/
		this.DataWritten = "";

	
	}

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*Read Body and Subject

	/*Subject is stored in message part of Draft get Message ID*/
	String messageId = sample.getMessage().getId();

	/*Request full Message content text/plain type or mime message type*/
	Message content = gmailService.users().messages().get(userId, messageId).setFormat("full").execute();
	MessagePart part = content.getPayload();
	//System.out.println(part);

	/*Get the Header List which consistes subject*/
	List<MessagePartHeader> header = part.getHeaders();


	/*Iterate through each header and check for Subject name*/
	for(MessagePartHeader head : header){

		if("Subject".equals(head.getName()) == true){

			//System.out.println("Subject of Mail = "+head.getValue());
			
			/*If Subject is Same what are we looking then decode message*/
			if(head.getValue().equals(this.filePath) == true){

				String type = part.getMimeType();
				
				/*If message only contains plainText then decode bytes*/
				if(type.equals("text/plain") == true){

					MessagePartBody body = part.getBody();
					byte[] m = body.decodeData();
					//System.out.println("Body Content : "+new String(m));
					bodyMessage = new String(m) + bodyMessage;

				
				}else{
					/*Else it contains encoded message extract it*/
					List<MessagePart> allParts = part.getParts();
					for(MessagePart p : allParts){
					
						if(p.getMimeType().equals("text/plain") == true){

							MessagePartBody body = p.getBody();
							byte[] m = body.decodeData();
							//System.out.println("Body Content : "+new String(m));
							bodyMessage = new String(m) + bodyMessage;
							

						}
					}
				}
			}
		}

	}

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