java/com/google/gerrit/server/mail/send/EmailSender.java

// Copyright (C) 2009 The Android Open Source Project
//
// 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.

package com.google.gerrit.server.mail.send;

import com.google.gerrit.common.Nullable;
import com.google.gerrit.entities.Address;
import com.google.gerrit.entities.EmailHeader;
import com.google.gerrit.exceptions.EmailException;
import java.util.Collection;
import java.util.Map;

/** Sends email messages to third parties. */
public interface EmailSender {
  boolean isEnabled();

  /**
   * Can the address receive messages from us?
   *
   * @param address the address to consider.
   * @return true if this sender will deliver to the address.
   */
  boolean canEmail(String address);

  /**
   * Sends an email message. Messages always contain a text body, but messages can optionally
   * include an additional HTML body. If both body types are present, {@code send} should construct
   * a {@code multipart/alternative} message with an appropriately-selected boundary.
   *
   * @param from who the message is from.
   * @param rcpt one or more address where the message will be delivered to. This list overrides any
   *     To or CC headers in {@code headers}.
   * @param headers message headers.
   * @param textBody text to appear in the {@code text/plain} body of the message.
   * @param htmlBody optional HTML code to appear in the {@code text/html} body of the message.
   * @throws EmailException the message cannot be sent.
   */
  default void send(
      Address from,
      Collection<Address> rcpt,
      Map<String, EmailHeader> headers,
      String textBody,
      @Nullable String htmlBody)
      throws EmailException {
    send(from, rcpt, headers, textBody);
  }

  /**
   * Sends an email message. Messages always contain a text body, but messages can optionally
   * include an additional HTML body and related resources. If both body types are present, {@code
   * send} should construct a {@code multipart/alternative} message with an appropriately-selected
   * boundary. If the HTML Resources are provided then html body and corresponding resources should
   * be grouped as {@code multipart/related}.
   *
   * @param from who the message is from.
   * @param rcpt one or more address where the message will be delivered to. This list overrides any
   *     To or CC headers in {@code headers}.
   * @param headers message headers.
   * @param textBody text to appear in the {@code text/plain} body of the message.
   * @param htmlBody optional HTML code to appear in the {@code text/html} body of the message.
   * @param htmlResources optional resources that can be referenced in HTML code using their {@link
   *     EmailResource#contentId}.
   * @throws EmailException the message cannot be sent.
   */
  default void send(
      Address from,
      Collection<Address> rcpt,
      Map<String, EmailHeader> headers,
      String textBody,
      @Nullable String htmlBody,
      Collection<EmailResource> htmlResources)
      throws EmailException {
    send(from, rcpt, headers, textBody, htmlBody);
  }

  /**
   * Sends an email message with a text body only (i.e. not HTML or multipart).
   *
   * <p>Authors of new implementations of this interface should not use this method to send a
   * message because this method does not accept the HTML body. Instead, authors should use the
   * above signature of {@code send}.
   *
   * <p>This version of the method is preserved for support of legacy implementations.
   *
   * @param from who the message is from.
   * @param rcpt one or more address where the message will be delivered to. This list overrides any
   *     To or CC headers in {@code headers}.
   * @param headers message headers.
   * @param body text to appear in the body of the message.
   * @throws EmailException the message cannot be sent.
   */
  void send(Address from, Collection<Address> rcpt, Map<String, EmailHeader> headers, String body)
      throws EmailException;
}