com.eclipsesource.connect.mail.MessageBuilder.java Source code

Introduction

Here is the source code for com.eclipsesource.connect.mail.MessageBuilder.java

Source

/*******************************************************************************
 * Copyright (c) 2015 EclipseSource and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Holger Staudacher - initial API and implementation, ongoing development
 ******************************************************************************/
package com.eclipsesource.connect.mail;

import static com.google.common.base.MoreObjects.firstNonNull;
import static com.google.common.base.Preconditions.checkArgument;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimePart;

import com.eclipsesource.connect.api.mail.Mail;
import com.eclipsesource.connect.api.mail.Mail.Attachement;
import com.google.common.io.ByteSource;

public class MessageBuilder {

    private final BodyProcessor bodyProcessor;
    private final Session session;
    private final String sender;

    public MessageBuilder(Session session, String sender, BodyProcessor bodyProcessor) {
        validateArguments(session, sender, bodyProcessor);
        this.session = session;
        this.sender = sender;
        this.bodyProcessor = bodyProcessor;
    }

    public Message build(Mail mail) {
        checkArgument(mail != null, "Mail must not be null");
        MimeMessage message = new MimeMessage(session);
        try {
            message.setFrom(new InternetAddress(sender));
            addRecipients(message, mail);
            message.setSubject(firstNonNull(mail.getSubject(), ""));
            handleBody(mail, message);
            return message;
        } catch (Exception shouldNotHappen) {
            throw new IllegalStateException(shouldNotHappen);
        }
    }

    private void validateArguments(Session session, String sender, BodyProcessor bodyProcessor) {
        checkArgument(session != null, "Session must not be null");
        checkArgument(sender != null, "Sender must not be null");
        checkArgument(!sender.trim().isEmpty(), "Sender must not be empty");
        checkArgument(bodyProcessor != null, "BodyProcessor must not be null");
    }

    private void addRecipients(MimeMessage message, Mail mail) {
        addTos(message, mail);
        addCCs(message, mail);
        addBCCs(message, mail);
    }

    private void addTos(MimeMessage message, Mail mail) {
        mail.getTos().forEach(to -> {
            try {
                message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            } catch (Exception shouldNotHappen) {
                throw new IllegalStateException(shouldNotHappen);
            }
        });
    }

    private void addCCs(MimeMessage message, Mail mail) {
        mail.getCCs().forEach(cc -> {
            try {
                message.addRecipient(Message.RecipientType.CC, new InternetAddress(cc));
            } catch (Exception shouldNotHappen) {
                throw new IllegalStateException(shouldNotHappen);
            }
        });
    }

    private void addBCCs(MimeMessage message, Mail mail) {
        mail.getBCCs().forEach(bcc -> {
            try {
                message.addRecipient(Message.RecipientType.BCC, new InternetAddress(bcc));
            } catch (Exception shouldNotHappen) {
                throw new IllegalStateException(shouldNotHappen);
            }
        });
    }

    private void handleBody(Mail mail, MimeMessage message) throws Exception {
        String body = bodyProcessor.getBody(mail);
        List<Attachement> attachements = mail.getAttachements();
        if (attachements.isEmpty()) {
            addBody(message, mail, body);
        } else {
            addBodyWithAttachements(message, mail, body, attachements);
        }
    }

    private void addBodyWithAttachements(MimeMessage message, Mail mail, String body,
            List<Attachement> attachements) throws Exception {
        Multipart multipart = new MimeMultipart();
        addMultiPartBody(mail, body, multipart);
        addAttachments(multipart, attachements);
        message.setContent(multipart);
    }

    private void addMultiPartBody(Mail mail, String body, Multipart multipart) throws Exception {
        MimeBodyPart bodyPart = new MimeBodyPart();
        addBody(bodyPart, mail, body);
        multipart.addBodyPart(bodyPart);
    }

    private void addBody(MimePart part, Mail mail, String body) throws MessagingException {
        if (mail.isHtml()) {
            part.setContent(firstNonNull(body, ""), "text/html; charset=utf-8");
        } else {
            part.setText(firstNonNull(body, ""));
        }
    }

    private void addAttachments(Multipart multipart, List<Attachement> attachements) throws Exception {
        for (Attachement attachement : attachements) {
            MimeBodyPart attachementPart = new MimeBodyPart();
            attachementPart.setFileName(attachement.getName());
            attachementPart.setContent(createAttachementContent(attachement), attachement.getType());
            multipart.addBodyPart(attachementPart);
        }
    }

    private byte[] createAttachementContent(Attachement attachement) throws IOException {
        return new ByteSource() {

            @Override
            public InputStream openStream() throws IOException {
                return attachement.getContent();
            }
        }.read();
    }
}