com.cloudhub.gmail.GmailEmailMessageExtractor.java Source code

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Here is the source code for com.cloudhub.gmail.GmailEmailMessageExtractor.java

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/*
 * Copyright (c) 2016 http://www.apache.org/licenses/LICENSE-2.0.
 */
package com.cloudhub.gmail;

import java.io.FileOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.MimeMessage;

import com.cloudhub.Options;
import com.cloudhub.extractor.EmailMessageExtractor;
import com.google.api.client.repackaged.org.apache.commons.codec.binary.Base64;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.model.Label;
import com.google.api.services.gmail.model.ListLabelsResponse;
import com.google.api.services.gmail.model.ListMessagesResponse;
import com.google.api.services.gmail.model.Message;

import com.google.api.services.gmail.model.MessagePart;
import com.google.api.services.gmail.model.MessagePartBody;

/**
 * <p>Extracts <i>actual</i> billing information from the invoice emailed by the specified provider.</p>
 *
 * @author sah2ed
 * @version 1.0
 */
public abstract class GmailEmailMessageExtractor extends EmailMessageExtractor {

    /**
     * Authorized Gmail API instance.
     */
    private Gmail service;

    /**
     *
     * User's email address. The special value "me"
     * can be used to indicate the authenticated user.
     */
    private String userId;

    /**
     * @param service Authorized Gmail API instance.
     */
    public GmailEmailMessageExtractor(Gmail service, String userId) {
        this.service = service;
        this.userId = userId;
    }

    /**
     * List all Messages of the user's mailbox matching the query.
     *
     * @param query String used to filter the Messages listed.
     * @throws IOException
     */
    public List<Message> listMessagesMatchingQuery(String query) throws IOException {
        ListMessagesResponse response = service.users().messages().list(userId).setQ(query).execute();

        List<Message> messages = new ArrayList<Message>();
        while (response.getMessages() != null) {
            messages.addAll(response.getMessages());
            if (response.getNextPageToken() != null) {
                String pageToken = response.getNextPageToken();
                response = service.users().messages().list(userId).setQ(query).setPageToken(pageToken).execute();
            } else {
                break;
            }
        }

        //      for (Message message : messages) {
        //         System.out.println(message.toPrettyString());
        //      }

        return messages;
    }

    /**
     * List all Messages of the user's mailbox with labelIds applied.
     *
     * @param labelIds Only return Messages with these labelIds applied.
     * @throws IOException
     */
    public List<Message> listMessagesWithLabels(List<String> labelIds) throws IOException {
        ListMessagesResponse response = service.users().messages().list(userId).setLabelIds(labelIds).execute();

        List<Message> messages = new ArrayList<Message>();
        while (response.getMessages() != null) {
            messages.addAll(response.getMessages());
            if (response.getNextPageToken() != null) {
                String pageToken = response.getNextPageToken();
                response = service.users().messages().list(userId).setLabelIds(labelIds).setPageToken(pageToken)
                        .execute();
            } else {
                break;
            }
        }

        for (Message message : messages) {
            System.out.println(message.toPrettyString());
        }

        return messages;
    }

    /**
     *
     * Prints all the labels in the user's inbox.
     * @throws IOException
     */
    public void printLabels() throws IOException {
        // Print the labels in the user's account.
        ListLabelsResponse listResponse = service.users().labels().list(userId).execute();
        List<Label> labels = listResponse.getLabels();
        if (labels.size() == 0) {
            System.out.println("No labels found.");
        } else {
            System.out.println("Labels:");
            for (Label label : labels) {
                System.out.printf("- %s\n", label.getName());
            }
        }
    }

    /**
     * Get Message with given ID.
     *
     * @param messageId ID of Message to retrieve.
     * @return Message Retrieved Message.
     * @throws IOException
     */
    public Message getMessage(String messageId) throws IOException {
        Message message = service.users().messages().get(userId, messageId).execute();

        // System.out.println("Message snippet: " + message.getSnippet());

        return message;
    }

    /**
     * Get a Message and use it to create a MimeMessage.
     *
     * @param messageId ID of Message to retrieve.
     * @return MimeMessage MimeMessage populated from retrieved Message.
     * @throws IOException
     * @throws MessagingException
     */
    public MimeMessage getMimeMessage(String messageId) throws IOException, MessagingException {
        Message message = service.users().messages().get(userId, messageId).setFormat("raw").execute();
        // System.out.println(message.toPrettyString());

        byte[] emailBytes = Base64.decodeBase64(message.getRaw());

        Properties props = new Properties();
        Session session = Session.getDefaultInstance(props, null);

        MimeMessage email = new MimeMessage(session, new ByteArrayInputStream(emailBytes));

        return email;
    }

    /**
     * Get the attachment in a given email.
     *
     * @param messageId ID of Message containing attachment..
     * @throws IOException
     */
    public File getAttachment(String messageId) throws IOException {
        File attachment = null;

        Message message = service.users().messages().get(userId, messageId).execute();
        List<MessagePart> parts = message.getPayload().getParts();
        for (MessagePart part : parts) {
            if (part.getFilename() != null && part.getFilename().length() > 0) {
                String filename = part.getFilename();
                String attId = part.getBody().getAttachmentId();
                MessagePartBody attachPart = service.users().messages().attachments().get(userId, messageId, attId)
                        .execute();
                byte[] fileByteArray = Base64.decodeBase64(attachPart.getData());

                attachment = new File(Options.DATA_FOLDER, filename);
                FileOutputStream fileOutFile = new FileOutputStream(attachment);
                fileOutFile.write(fileByteArray);
                fileOutFile.close();

                break;
            }
        }

        return attachment;
    }

}