org.springintegration.demo.service.EmailTransformer.java Source code

Introduction

Here is the source code for org.springintegration.demo.service.EmailTransformer.java

Source

package org.springintegration.demo.service;

/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import javax.mail.BodyPart;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Part;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.integration.Message;
import org.springframework.integration.file.FileHeaders;
import org.springframework.integration.support.MessageBuilder;

/**
 * Parses the E-mail Message and converts each containing message and/or attachment into
 * individual Spring Integration messages.
 *
 * @author Gunnar Hillert
 * @version 1.0
 *
 */
public class EmailTransformer {

    private static final Logger LOGGER = LoggerFactory.getLogger(EmailTransformer.class);

    public List<Message<?>> transformit(javax.mail.Message mailMessage) {

        final List<Message<?>> messages = new ArrayList<Message<?>>();

        handleMessage(mailMessage, messages);

        return messages;
    }

    public void handleMessage(javax.mail.Message mailMessage, List<Message<?>> messages) {

        Object content;

        try {
            content = mailMessage.getContent();
        } catch (IOException e) {
            throw new IllegalStateException("Error while retrieving the email contents.", e);
        } catch (MessagingException e) {
            throw new IllegalStateException("Error while retrieving the email contents.", e);
        }

        if (content instanceof String) {

            messages.add(MessageBuilder.withPayload((content)).build());

        } else if (content instanceof Multipart) {

            Multipart multipart = (Multipart) content;
            handleMultipart(multipart, mailMessage, messages);

        } else {
            throw new IllegalStateException(
                    "This content type is not supported - " + content.getClass().getSimpleName());
        }

    }

    public void handleMultipart(Multipart multipart, javax.mail.Message mailMessage, List<Message<?>> messages) {
        final int count;
        try {
            count = multipart.getCount();
        } catch (MessagingException e) {
            throw new IllegalStateException("Error while retrieving the number of enclosed BodyPart objects.", e);
        }

        for (int i = 0; i < count; i++) {

            final BodyPart bp;

            try {
                bp = multipart.getBodyPart(i);
            } catch (MessagingException e) {
                throw new IllegalStateException("Error while retrieving body part.", e);
            }

            final String contentType;
            final String filename;
            final String disposition;
            final String subject;

            try {
                contentType = bp.getContentType();
                filename = bp.getFileName();
                disposition = bp.getDisposition();
                subject = mailMessage.getSubject();

            } catch (MessagingException e) {
                throw new IllegalStateException("Unable to retrieve body part meta data.", e);
            }

            if (Part.ATTACHMENT.equalsIgnoreCase(disposition)) {
                LOGGER.info("Handdling attachment '{}', type: '{}'", filename, contentType);
            }

            final Object content;

            try {
                content = bp.getContent();
            } catch (IOException e) {
                throw new IllegalStateException("Error while retrieving the email contents.", e);
            } catch (MessagingException e) {
                throw new IllegalStateException("Error while retrieving the email contents.", e);
            }

            if (content instanceof String) {

                final Message<String> message = MessageBuilder.withPayload((String) content)
                        .setHeader(FileHeaders.FILENAME, subject + ".txt").build();

                messages.add(message);

            } else if (content instanceof InputStream) {

                InputStream inputStream = (InputStream) content;
                ByteArrayOutputStream bis = new ByteArrayOutputStream();

                try {
                    IOUtils.copy(inputStream, bis);
                } catch (IOException e) {
                    throw new IllegalStateException(
                            "Error while copying input stream to the ByteArrayOutputStream.", e);
                }

                Message<byte[]> message = MessageBuilder.withPayload((bis.toByteArray()))
                        .setHeader(FileHeaders.FILENAME, filename).build();

                messages.add(message);

            } else if (content instanceof javax.mail.Message) {
                handleMessage((javax.mail.Message) content, messages);
            } else if (content instanceof Multipart) {
                Multipart mp2 = (Multipart) content;
                handleMultipart(mp2, mailMessage, messages);
            } else {
                throw new IllegalStateException("Content type not handled: " + content.getClass().getSimpleName());
            }
        }

    }

}