Quickstarts explain how to set up and run an app that calls a Google Workspace API.
Google Workspace quickstarts use the API client libraries to handle some details of the authentication and authorization flow. We recommend that you use the client libraries for your own apps. This quickstart uses a simplified authentication approach that is appropriate for a testing environment. For a production environment, we recommend learning about authentication and authorization before choosing the access credentials that are appropriate for your app.
Create a Java command-line application that makes requests to the Google Chat API.
Objectives
- Set up your environment.
- Set up the sample.
- Run the sample.
Prerequisites
- Java 1.8 or greater.
- Gradle 7.0 or greater.
- A Google Cloud project.
- A Business or Enterprise Google Workspace account with access to Google Chat.
Set up your environment
To complete this quickstart, set up your environment.
Enable the API
Before using Google APIs, you need to turn them on in a Google Cloud project. You can turn on one or more APIs in a single Google Cloud project.In the Google Cloud console, enable the Google Chat API.
Configure the OAuth consent screen
If you're using a new Google Cloud project to complete this quickstart, configure the OAuth consent screen and add yourself as a test user. If you've already completed this step for your Cloud project, skip to the next section.
- In the Google Cloud console, go to Menu > APIs & Services > OAuth consent screen.
- For User type select Internal, then click Create.
- Complete the app registration form, then click Save and Continue.
For now, you can skip adding scopes and click Save and Continue. In the future, when you create an app for use outside of your Google Workspace organization, you must change the User type to External, and then, add the authorization scopes that your app requires.
- Review your app registration summary. To make changes, click Edit. If the app registration looks OK, click Back to Dashboard.
Authorize credentials for a desktop application
To authenticate end users and access user data in your app, you need to create one or more OAuth 2.0 Client IDs. A client ID is used to identify a single app to Google's OAuth servers. If your app runs on multiple platforms, you must create a separate client ID for each platform.- In the Google Cloud console, go to Menu > APIs & Services > Credentials.
- Click Create Credentials > OAuth client ID.
- Click Application type > Desktop app.
- In the Name field, type a name for the credential. This name is only shown in the Google Cloud console.
- Click Create. The OAuth client created screen appears, showing your new Client ID and Client secret.
- Click OK. The newly created credential appears under OAuth 2.0 Client IDs.
- Save the downloaded JSON file as
credentials.json
, and move the file to your working directory.
Configure the Google Chat app
To call the Google Chat API, you must configure a Google Chat app. For any write requests, Google Chat attributes the Google Chat app in the UI using the following information.
In the Google Cloud console, go to the Chat API Configuration page:
Under Application info, enter the following information:
- In the App name field, enter
Chat API quickstart app
. - In the Avatar URL field, enter
https://developers.google.com/chat/images/quickstart-app-avatar.png
. - In the Description field, enter
Quickstart for calling the Chat API
.
- In the App name field, enter
Under Interactive features, click the Enable interactive features toggle to the off position to disable interactive features for the Chat app.
Click Save.
Prepare the workspace
In your working directory, create a new project structure:
gradle init --type basic mkdir -p src/main/java src/main/resources
In the
src/main/resources/
directory, copy thecredentials.json
file that you previously downloaded.Open the default
build.gradle
file and replace its contents with the following code:
Set up the sample
In the
src/main/java/
directory, create a new Java file with a name that matches themainClassName
value in yourbuild.gradle
file.Include the following code in your new Java file:
Run the sample
Run the sample:
gradle run
-
The first time you run the sample, it prompts you to authorize access:
- If you're not already signed in to your Google Account, sign in when prompted. If you're signed in to multiple accounts, select one account to use for authorization.
- Click Accept.
Your Java application runs and calls the Google Chat API.
Authorization information is stored in the file system, so the next time you run the sample code, you aren't prompted for authorization.