推送通知 (Dialogflow)

在 Dialogflow 中探索

点击继续,将通知示例导入 Dialogflow 中。然后,按照以下步骤部署和测试该示例:

  1. 输入代理名称并为示例创建新的 Dialogflow 代理。
  2. 代理导入完成后,点击转至代理 (Go to agent)。
  3. 在主导航菜单中,前往 Fulfillment
  4. 启用内嵌编辑器,然后点击部署。编辑器包含示例代码。
  5. 在主导航菜单中,点击 Integrations(集成),然后点击 Google Assistant
  6. 在显示的模态窗口中,启用 Auto-preview changes,然后点击 Test 打开 Actions 模拟器。
  7. 在模拟器中,输入 Talk to my test app 以测试示例!
继续

您的 Action 可以在相关时刻向用户推送通知,例如在任务截止日期临近时发送提醒。

在本指南中,我们使用 Actions on Google 提示示例作为参考,向您展示如何为 Action 设置推送通知。 当用户调用此 Action 时,系统会询问他们是否想要听取关于开发自己的 Action 的提示。用户可以为小费选择特定或随机选择的类别,也可以选择听取最新的提示。

支持的表面

推送通知适用于 Android 和 iOS 设备(iOS 设备必须安装 Google 助理应用才能接收推送通知)。声控音箱、智能显示屏或其他 surface 目前不支持这些选项。

前提条件

您的 Actions 项目中必须至少有一个 Action 必须配置为触发 intent,当用户点按从 Google 助理收到的通知时,系统就会调用该 intent。

您的 Action 无法配置为从推送通知触发默认欢迎 intent。

控制台设置

如需为您的 Action 添加对推送通知的支持,请执行以下操作:

  1. 前往 Actions 控制台并依次转到 Build > Actions

  2. 点击与要为其启用推送通知的其他触发 intent 匹配的 Action。

    对于 Actions on Google 提示示例,您需要选择“tell_latest_tip”。

  3. 向下滚动到用户互动部分,然后启用您是否想发送推送通知

  4. 输入内容标题

    对于 Actions on Google 提示示例,标题可以是“新提示已添加”。

  5. 点击保存

导入

在接下来的部分中,您需要在 fulfillment 代码中声明以下导入:

Dialogflow
const {
  dialogflow,
  UpdatePermission,
  Suggestions,
} = require('actions-on-google');
Actions SDK
const {
  actionssdk,
  UpdatePermission,
  Suggestions,
} = require('actions-on-google');

选择订阅的用户

您必须先让用户选择接收,然后才能向用户发送推送通知。 为此,您可以向其显示建议内容信息条以征求其许可。 当用户授予权限后,您会收到更新用户 ID,以便向该用户发送推送通知。

显示用于选择订阅的建议内容信息卡

您必须先向用户显示一个建议条状标签,邀请他们选择接收推送通知,用户才能接收来自您的 Action 的推送通知。

以下代码段会随文本回复一起向用户发送“提醒我有新提示”建议条状标签。

Dialogflow Node.js
conv.ask('I can send you push notifications. Would you like that?');
conv.ask(new Suggestions('Send notifications'));
Actions SDK Node.js
conv.ask(' I can send you push notifications. Would you like that?');
conv.ask(new Suggestions('Send notifications'));
Dialogflow Java
responseBuilder
    .add("I can send you push notifications. Would you like that?")
    .addSuggestions(new String[] {
        "Send notifications"
    });
Actions SDK Java
responseBuilder
    .add("I can send you push notifications. Would you like that?")
    .addSuggestions(new String[] {
        "Send notifications"
    });
Dialogflow JSON

请注意,以下 JSON 描述了 webhook 响应。

{
  "payload": {
    "google": {
      "expectUserResponse": true,
      "richResponse": {
        "items": [
          {
            "simpleResponse": {
              "textToSpeech": "Hi! Welcome to Push Notifications!"
            }
          },
          {
            "simpleResponse": {
              "textToSpeech": "I can send you push notifications. Would you like that?"
            }
          }
        ],
        "suggestions": [
          {
            "title": "Send notifications"
          }
        ]
      }
    }
  }
}
Actions SDK JSON

请注意,以下 JSON 描述了 webhook 响应。

{
  "expectUserResponse": true,
  "expectedInputs": [
    {
      "possibleIntents": [
        {
          "intent": "actions.intent.TEXT"
        }
      ],
      "inputPrompt": {
        "richInitialPrompt": {
          "items": [
            {
              "simpleResponse": {
                "textToSpeech": "Hi! Welcome to Push Notifications!"
              }
            },
            {
              "simpleResponse": {
                "textToSpeech": " I can send you push notifications. Would you like that?"
              }
            }
          ],
          "suggestions": [
            {
              "title": "Send notifications"
            }
          ]
        }
      }
    }
  ]
}

在用户点按条状标签后,您必须请求对方授予 UPDATE 权限。 以下代码展示了如何使用 Node.js 客户端库的 askForUpdatePermission 函数执行此操作。

Dialogflow Node.js
  1. 在 Dialogflow 控制台中打开您的代理,然后选择您要为其配置更新的意图。
  2. 向下滚动到响应,然后打开 Google 助理标签页。
  3. 点击添加邮件内容,然后选择建议内容信息条
  4. 将条状标签文本设为吸引用户选择加入的内容。在 Actions on Google 提示示例中,我们将条状标签设置为 Alert me of new Tips
  5. 添加另一个 Dialogflow intent(例如 setup_push),并设置相应的操作(例如 setup.push)。此 intent 的用户表述必须与选择接受条状标签的文本(如示例提醒我新提示中所述)相匹配。
以下代码段展示了如何使用适用于 Node.js 的 Actions on Google 客户端库请求权限:
app.intent('Subscribe to Notifications', (conv) => {
  conv.ask(new UpdatePermission({
    intent: 'Notification',
  }));
});
Actions SDK Node.js

您应该配置 NLU 解决方案以触发一个函数,该函数会在用户表述与选择启用推送通知提示的值匹配时询问权限。下面是一个基于字符串匹配的非常基本的示例:

conv.ask(new UpdatePermission({
  intent: 'Notification',
}));
Dialogflow Java
  1. 在 Dialogflow 控制台中打开您的代理,然后选择您要为其配置更新的意图。
  2. 向下滚动到响应,然后打开 Google 助理标签页。
  3. 点击添加邮件内容,然后选择建议内容信息条
  4. 将条状标签文本设为吸引用户选择加入的内容。在 Actions on Google 提示示例中,我们将条状标签设置为 Alert me of new Tips
  5. 添加另一个 Dialogflow intent(例如 setup_push),并设置相应的操作(例如 setup.push)。此 intent 的用户表述必须与选择接受条状标签的文本(如示例提醒我新提示中所述)相匹配。
以下代码段展示了如何使用 Actions on Google Java/Kotlin 客户端库请求权限:
@ForIntent("Subscribe to Notifications")
public ActionResponse subscribeToNotifications(ActionRequest request) {
  ResponseBuilder responseBuilder = getResponseBuilder(request);
  responseBuilder.add(new UpdatePermission().setIntent("Notification"));
  return responseBuilder.build();
}
Actions SDK Java

您应该配置 NLU 解决方案以触发一个函数,该函数会在用户表述与选择启用推送通知提示的值匹配时询问权限。下面是一个基于字符串匹配的非常基本的示例:

ResponseBuilder responseBuilder = getResponseBuilder(request);
responseBuilder.add(new UpdatePermission().setIntent("Notification"));
return responseBuilder.build();
Dialogflow JSON

请注意,下面的 JSON 描述了使用 Dialogflow 的 webhook 响应。

{
  "payload": {
    "google": {
      "expectUserResponse": true,
      "systemIntent": {
        "intent": "actions.intent.PERMISSION",
        "data": {
          "@type": "type.googleapis.com/google.actions.v2.PermissionValueSpec",
          "permissions": [
            "UPDATE"
          ],
          "updatePermissionValueSpec": {
            "intent": "tell_latest_tip"
          }
        }
      }
    }
  }
}
Actions SDK JSON

请注意,以下 JSON 描述了使用 Actions SDK 的 webhook 响应。

{
  "expectUserResponse": true,
  "expectedInputs": [
    {
      "possibleIntents": [
        {
          "intent": "actions.intent.PERMISSION",
          "inputValueData": {
            "@type": "type.googleapis.com/google.actions.v2.PermissionValueSpec",
            "permissions": [
              "UPDATE"
            ],
            "updatePermissionValueSpec": {
              "intent": "tell_latest_tip"
            }
          }
        }
      ]
    }
  ]
}

完成订阅

如需通过 Node.js 网络钩子完成订阅,您需要保存用户的通知 ID 及其选择的 intent。如果用户授予权限,两者会作为参数传递。

如果您的 Action 是使用 Dialogflow 构建的,您需要执行以下操作:

  • 添加一个用于处理 actions_intent_PERMISSION 的 intent。
  • 将 intent 的 Action 名称指定为网络钩子,以便稍后过滤。

以下代码展示了如何处理名为 finish_push_setup 且 Action 名称为 finish.push.setup 的 intent 的 Dialogflow intent:

Dialogflow Node.js
app.intent('Confirm Notifications Subscription', (conv) => {
  if (conv.arguments.get('PERMISSION')) {
    const updatesUserId = conv.arguments.get('UPDATES_USER_ID');
    // Store user ID in database for later use
    conv.close(`Ok, I'll start alerting you.`);
  } else {
    conv.close(`Ok, I won't alert you.`);
  }
});
Actions SDK Node.js
app.intent('actions.intent.PERMISSION', (conv) => {
  if (conv.arguments.get('PERMISSION')) {
    const updatesUserId = conv.arguments.get('UPDATES_USER_ID');
    // Store user ID in database for later use
    conv.close(`Ok, I'll start alerting you.`);
  } else {
    conv.close(`Ok, I won't alert you.`);
  }
});
Dialogflow Java
@ForIntent("Confirm Notifications Subscription")
public ActionResponse confirmNotificationsSubscription(ActionRequest request) {
  // Verify the user has subscribed for push notifications
  ResponseBuilder responseBuilder = getResponseBuilder(request);
  if (request.isPermissionGranted()) {
    Argument userId = request.getArgument(ConstantsKt.ARG_UPDATES_USER_ID);
    if (userId != null) {
      // Store the user's ID in the database
    }
    responseBuilder.add("Ok, I'll start alerting you.");
  } else {
    responseBuilder.add("Ok, I won't alert you.");
  }
  responseBuilder.endConversation();
  return responseBuilder.build();
}
Actions SDK Java
@ForIntent("actions.intent.PERMISSION")
public ActionResponse confirmNotificationsSubscription(ActionRequest request) {
  // Verify the user has subscribed for push notifications
  ResponseBuilder responseBuilder = getResponseBuilder(request);
  if (request.isPermissionGranted()) {
    Argument userId = request.getArgument(ConstantsKt.ARG_UPDATES_USER_ID);
    if (userId != null) {
      // Store the user's ID in the database
    }
    responseBuilder.add("Ok, I'll start alerting you.");
  } else {
    responseBuilder.add("Ok, I won't alert you.");
  }
  responseBuilder.endConversation();
  return responseBuilder.build();
}
Dialogflow JSON

请注意,下面的 JSON 描述了对 webhook 的请求。

{
  "responseId": "ee9e7ed5-fa1a-48c6-aac7-f9fbe94f1f58-712767ed",
  "queryResult": {
    "queryText": "actions_intent_PERMISSION",
    "action": "confirm.subscription",
    "parameters": {},
    "allRequiredParamsPresent": true,
    "fulfillmentMessages": [
      {
        "text": {
          "text": [
            ""
          ]
        }
      }
    ],
    "outputContexts": [
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_capability_screen_output"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_capability_account_linking"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_capability_media_response_audio"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_capability_audio_output"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_capability_web_browser"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/google_assistant_input_type_keyboard"
      },
      {
        "name": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k/contexts/actions_intent_permission",
        "parameters": {
          "PERMISSION": true,
          "text": "yes",
          "UPDATES_USER_ID": "ABwppHHssyPbvEBF1mgN7Ddwb7mkhiVohW9PZ--I_svqy7zFElA4DHkf9pn04UBd5gwZo26_RfXCQ8otcztyIfe6MCQ"
        }
      }
    ],
    "intent": {
      "name": "projects/PROJECT_ID/agent/intents/c7f7b30b-5b88-4bb5-b0b8-1cd0862d1dd2",
      "displayName": "Confirm Notifications Subscription"
    },
    "intentDetectionConfidence": 1,
    "languageCode": "en"
  },
  "originalDetectIntentRequest": {
    "source": "google",
    "version": "2",
    "payload": {
      "user": {
        "permissions": [
          "UPDATE"
        ],
        "locale": "en-US",
        "userVerificationStatus": "VERIFIED"
      },
      "conversation": {
        "conversationId": "ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k",
        "type": "ACTIVE",
        "conversationToken": "[]"
      },
      "inputs": [
        {
          "intent": "actions.intent.PERMISSION",
          "rawInputs": [
            {
              "inputType": "KEYBOARD",
              "query": "yes"
            }
          ],
          "arguments": [
            {
              "name": "PERMISSION",
              "boolValue": true,
              "textValue": "true"
            },
            {
              "name": "text",
              "rawText": "yes",
              "textValue": "yes"
            },
            {
              "name": "UPDATES_USER_ID",
              "textValue": "ABwppHHssyPbvEBF1mgN7Ddwb7mkhiVohW9PZ--I_svqy7zFElA4DHkf9pn04UBd5gwZo26_RfXCQ8otcztyIfe6MCQ"
            }
          ]
        }
      ],
      "surface": {
        "capabilities": [
          {
            "name": "actions.capability.SCREEN_OUTPUT"
          },
          {
            "name": "actions.capability.ACCOUNT_LINKING"
          },
          {
            "name": "actions.capability.MEDIA_RESPONSE_AUDIO"
          },
          {
            "name": "actions.capability.AUDIO_OUTPUT"
          },
          {
            "name": "actions.capability.WEB_BROWSER"
          }
        ]
      },
      "availableSurfaces": [
        {
          "capabilities": [
            {
              "name": "actions.capability.AUDIO_OUTPUT"
            },
            {
              "name": "actions.capability.SCREEN_OUTPUT"
            },
            {
              "name": "actions.capability.WEB_BROWSER"
            }
          ]
        }
      ]
    }
  },
  "session": "projects/PROJECT_ID/agent/sessions/ABwppHGIgmmU3zBcYMF_vWoHaM4JUo3wniYBHdbUF25l63G7EQWjRnlne8Ar7AOcRHWn1lrEKGy8qdP0UXLcWDBq93k"
}
Actions SDK JSON

请注意,下面的 JSON 描述了对 webhook 的请求。

{
  "user": {
    "permissions": [
      "UPDATE"
    ],
    "locale": "en-US",
    "userVerificationStatus": "VERIFIED"
  },
  "conversation": {
    "conversationId": "ABwppHEP6OAFZHkSGEiZ5HYM9qrlk8YtIH1DQmJ52cxXELSPvM-kSc_tMJ_5O6ITbgVJlY9i2FIsKWjE_HXLke48",
    "type": "NEW"
  },
  "inputs": [
    {
      "intent": "actions.intent.PERMISSION",
      "rawInputs": [
        {
          "inputType": "KEYBOARD",
          "query": "yes"
        }
      ],
      "arguments": [
        {
          "name": "PERMISSION",
          "boolValue": true,
          "textValue": "true"
        },
        {
          "name": "text",
          "rawText": "yes",
          "textValue": "yes"
        },
        {
          "name": "UPDATES_USER_ID",
          "textValue": "ABwppHFvBKC-tMYUsUjJkm3YECgZvd6A3sOc7KuQvO4ZdQX3bGLmyoQ41dh4Zmtlzv_kaOKBt1Sf6eRpNbayynrl"
        }
      ]
    }
  ],
  "surface": {
    "capabilities": [
      {
        "name": "actions.capability.AUDIO_OUTPUT"
      },
      {
        "name": "actions.capability.WEB_BROWSER"
      },
      {
        "name": "actions.capability.SCREEN_OUTPUT"
      },
      {
        "name": "actions.capability.ACCOUNT_LINKING"
      },
      {
        "name": "actions.capability.MEDIA_RESPONSE_AUDIO"
      }
    ]
  },
  "availableSurfaces": [
    {
      "capabilities": [
        {
          "name": "actions.capability.AUDIO_OUTPUT"
        },
        {
          "name": "actions.capability.SCREEN_OUTPUT"
        },
        {
          "name": "actions.capability.WEB_BROWSER"
        }
      ]
    }
  ]
}

发送通知

您可以使用 Actions API 向用户发送推送通知。如需使用此 API,您需要在 Google Cloud 项目中激活此 API,并设置并下载 JSON 服务帐号密钥。请参阅此处代码示例中的说明的第 8 步。

然后,您可以使用 Google OAuth2 客户端库,用服务帐号密钥交换访问令牌,并使用该令牌验证您向 Actions API 发出的请求。

获取服务账号密钥

  1. 前往以下网址,将末尾的“example-project-1”替换为 Actions 控制台中的项目 ID:https://console.developers.google.com/apis/api/actions.googleapis.com/overview?project=example-project-1
  2. 如果您看到启用按钮,请点击该按钮。否则,请继续执行第 3 步。
  3. 前往以下网址,将末尾的“example-project-1”替换为 Actions 控制台中的项目 ID:https://console.developers.google.com/apis/credentials?project=example-project-1
  4. 点击创建凭据 > 服务帐号密钥
  5. 点击 Service Account 下的 Select 框,然后点击 New Service Account
  6. 为服务帐号指定名称(例如“notifications”等)和 Project Owner角色
  7. 选择 JSON 密钥类型,然后点击创建。一个 JSON 服务帐号密钥将下载到您的本地机器。

用密钥交换访问令牌并发送通知

如需通过 Actions API 发送通知,您需要将服务帐号密钥交换为访问令牌。为此,我们建议您使用 Google API 客户端库。在接下来的一系列代码段中,我们使用的是 Google API Node.js 客户端库。

  1. 安装 Google API 客户端库并请求:npm install googleapis request --save
  2. 使用以下代码从服务帐号密钥获取访问令牌并发送推送通知:
Dialogflow Node.js
const {google} = require('googleapis');
const request = require('request');

const jwtClient = new google.auth.JWT(
  serviceAccount.client_email, null, serviceAccount.private_key,
  ['https://www.googleapis.com/auth/actions.fulfillment.conversation'],
  null
);

jwtClient.authorize((err, tokens) => {
  if (!err) {
    request.post('https://actions.googleapis.com/v2/conversations:send', {
      auth: {
        bearer: tokens.access_token,
      },
      json: true,
      body: {
        customPushMessage: {
          userNotification: {
            title: 'Push Notification Title',
          },
          target: {
            userId: '<UPDATES_USER_ID>',
            intent: 'Notification Intent',
          },
        },
        isInSandbox: true,
      },
    }, (err, httpResponse, body) => {
      console.log(`${httpResponse.statusCode}: ${httpResponse.statusMessage}`);
    });
  }
});
Actions SDK Node.js
const {google} = require('googleapis');
const request = require('request');

const jwtClient = new google.auth.JWT(
  serviceAccount.client_email, null, serviceAccount.private_key,
  ['https://www.googleapis.com/auth/actions.fulfillment.conversation'],
  null
);

jwtClient.authorize((err, tokens) => {
  if (!err) {
    request.post('https://actions.googleapis.com/v2/conversations:send', {
      auth: {
        bearer: tokens.access_token,
      },
      json: true,
      body: {
        customPushMessage: {
          userNotification: {
            title: 'Push Notification Title',
          },
          target: {
            userId: '<UPDATES_ORDER_ID>',
            intent: 'Notification Intent',
          },
        },
        isInSandbox: true,
      },
    }, (err, httpResponse, body) => {
      console.log(`${httpResponse.statusCode}: ${httpResponse.statusMessage}`);
    });
  }
});
Dialogflow Java
final class Notification {

  private final String title;

  Notification(String title) {
    this.title = title;
  }

  String getTitle() {
    return title;
  }
}

final class Target {

  private final String userId;
  private final String intent;
  private final String locale;

  Target(String userId, String intent, String locale) {
    this.userId = userId;
    this.intent = intent;
    this.locale = locale;
  }

  String getUserId() {
    return userId;
  }

  String getIntent() {
    return intent;
  }

  String getLocale() {
    return locale;
  }
}

final class PushMessage {

  private final Notification userNotification;
  private final Target target;

  PushMessage(Notification userNotification, Target target) {
    this.userNotification = userNotification;
    this.target = target;
  }

  Notification getUserNotification() {
    return userNotification;
  }

  Target getTarget() {
    return target;
  }
}

final class PushNotification {

  private final PushMessage customPushMessage;
  private boolean isInSandbox;

  PushNotification(PushMessage customPushMessage, boolean isInSandbox) {
    this.customPushMessage = customPushMessage;
    this.isInSandbox = isInSandbox;
  }

  PushMessage getCustomPushMessage() {
    return customPushMessage;
  }

  boolean getIsInSandbox() {
    return isInSandbox;
  }
}

private PushNotification createNotification(String title, String userId, String intent, String locale) {
  Notification notification = new Notification(title);
  Target target = new Target(userId, intent, locale);
  PushMessage message = new PushMessage(notification, target);
  boolean isInSandbox = true;
  return new PushNotification(message, isInSandbox);
}

private ServiceAccountCredentials loadCredentials() throws IOException {
  String actionsApiServiceAccountFile =
      this.getClass().getClassLoader().getResource("service-account.json").getFile();
  InputStream actionsApiServiceAccount = new FileInputStream(actionsApiServiceAccountFile);
  ServiceAccountCredentials serviceAccountCredentials =
      ServiceAccountCredentials.fromStream(actionsApiServiceAccount);
  return (ServiceAccountCredentials)
      serviceAccountCredentials.createScoped(
          Collections.singleton(
              "https://www.googleapis.com/auth/actions.fulfillment.conversation"));
}

private String getAccessToken() throws IOException {
  AccessToken token = loadCredentials().refreshAccessToken();
  return token.getTokenValue();
}

public void sendNotification(String title, String userId, String intent, String locale) throws IOException {
  Preconditions.checkNotNull(title, "title cannot be null.");
  Preconditions.checkNotNull(userId, "userId cannot be null.");
  Preconditions.checkNotNull(intent, "intent cannot be null.");
  Preconditions.checkNotNull(locale, "locale cannot be null");
  PushNotification notification = createNotification(title, userId, intent, locale);

  HttpPost request = new HttpPost("https://actions.googleapis.com/v2/conversations:send");

  String token = getAccessToken();

  request.setHeader("Content-type", "application/json");
  request.setHeader("Authorization", "Bearer " + token);

  StringEntity entity = new StringEntity(new Gson().toJson(notification));
  entity.setContentType(ContentType.APPLICATION_JSON.getMimeType());
  request.setEntity(entity);
  HttpClient httpClient = HttpClientBuilder.create().build();
  httpClient.execute(request);
}
Actions SDK Java
final class Notification {

  private final String title;

  Notification(String title) {
    this.title = title;
  }

  String getTitle() {
    return title;
  }
}

final class Target {

  private final String userId;
  private final String intent;

  Target(String userId, String intent) {
    this.userId = userId;
    this.intent = intent;
  }

  String getUserId() {
    return userId;
  }

  String getIntent() {
    return intent;
  }
}

final class PushMessage {

  private final Notification userNotification;
  private final Target target;

  PushMessage(Notification userNotification, Target target) {
    this.userNotification = userNotification;
    this.target = target;
  }

  Notification getUserNotification() {
    return userNotification;
  }

  Target getTarget() {
    return target;
  }
}

final class PushNotification {

  private final PushMessage customPushMessage;
  private boolean isInSandbox;

  PushNotification(PushMessage customPushMessage, boolean isInSandbox) {
    this.customPushMessage = customPushMessage;
    this.isInSandbox = isInSandbox;
  }

  PushMessage getCustomPushMessage() {
    return customPushMessage;
  }

  boolean getIsInSandbox() {
    return isInSandbox;
  }
}

private PushNotification createNotification(String title, String userId, String intent) {
  Notification notification = new Notification(title);
  Target target = new Target(userId, intent);
  PushMessage message = new PushMessage(notification, target);
  boolean isInSandbox = true;
  return new PushNotification(message, isInSandbox);
}

private ServiceAccountCredentials loadCredentials() throws IOException {
  String actionsApiServiceAccountFile =
      this.getClass().getClassLoader().getResource("service-account.json").getFile();
  InputStream actionsApiServiceAccount = new FileInputStream(actionsApiServiceAccountFile);
  ServiceAccountCredentials serviceAccountCredentials =
      ServiceAccountCredentials.fromStream(actionsApiServiceAccount);
  return (ServiceAccountCredentials)
      serviceAccountCredentials.createScoped(
          Collections.singleton(
              "https://www.googleapis.com/auth/actions.fulfillment.conversation"));
}

private String getAccessToken() throws IOException {
  AccessToken token = loadCredentials().refreshAccessToken();
  return token.getTokenValue();
}

public void sendNotification(String title, String userId, String intent) throws IOException {
  Preconditions.checkNotNull(title, "title cannot be null.");
  Preconditions.checkNotNull(userId, "userId cannot be null.");
  Preconditions.checkNotNull(intent, "intent cannot be null.");
  PushNotification notification = createNotification(title, userId, intent);

  HttpPost request = new HttpPost("https://actions.googleapis.com/v2/conversations:send");

  String token = getAccessToken();

  request.setHeader("Content-type", "application/json");
  request.setHeader("Authorization", "Bearer " + token);

  StringEntity entity = new StringEntity(new Gson().toJson(notification));
  entity.setContentType(ContentType.APPLICATION_JSON.getMimeType());
  request.setEntity(entity);
  HttpClient httpClient = HttpClientBuilder.create().build();
  httpClient.execute(request);
}