feat: Add Google Chat API quickstart (#1061)

* feat: Add Google Chat API quickstart

* Fix Google Style

---------

Co-authored-by: pierrick <[email protected]>

chat/quickstart/README.md

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+# Google Chat Java Quickstart
+
+Complete the steps described in the [quickstart instructions](
+https://developers.google.com/workspace/chat/api/guides/quickstart/java),
+and in about five minutes you'll have a simple Java command-line
+application that makes requests to the Google Chat API.
+
+## Run
+
+After following the quickstart setup instructions, run the sample:
+
+`gradle run`

chat/quickstart/build.gradle

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+apply plugin: 'java'
+apply plugin: 'application'
+
+mainClassName = 'ChatQuickstart'
+sourceCompatibility = 11
+targetCompatibility = 11
+version = '1.0'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation 'com.google.auth:google-auth-library-oauth2-http:1.23.0'
+    implementation 'com.google.api-client:google-api-client:1.33.0'
+    implementation 'com.google.api.grpc:proto-google-cloud-chat-v1:0.8.0'
+    implementation 'com.google.api:gax:2.48.1'
+    implementation 'com.google.cloud:google-cloud-chat:0.1.0'
+    implementation 'com.google.oauth-client:google-oauth-client-jetty:1.34.1'
+}

chat/quickstart/settings.gradle

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+/*
+ * This settings file was generated by the Gradle 'init' task.
+ *
+ * The settings file is used to specify which projects to include in your build.
+ * In a single project build this file can be empty or even removed.
+ *
+ * Detailed information about configuring a multi-project build in Gradle can be found
+ * in the user guide at https://docs.gradle.org/3.5/userguide/multi_project_builds.html
+ */
+
+/*
+// To declare projects as part of a multi-project build use the 'include' method
+include 'shared'
+include 'api'
+include 'services:webservice'
+*/
+
+rootProject.name = 'quickstart'

chat/quickstart/src/main/java/ChatQuickstart.java

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+// Copyright 2024 Google LLC
+//
+// 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.
+
+// [START chat_quickstart]
+
+import com.google.api.client.auth.oauth2.Credential;
+import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
+import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
+import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
+import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
+import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
+import com.google.api.client.json.JsonFactory;
+import com.google.api.client.json.gson.GsonFactory;
+import com.google.api.client.util.store.FileDataStoreFactory;
+import com.google.api.gax.core.FixedCredentialsProvider;
+import com.google.auth.Credentials;
+import com.google.auth.oauth2.AccessToken;
+import com.google.auth.oauth2.UserCredentials;
+import com.google.chat.v1.ChatServiceClient;
+import com.google.chat.v1.ChatServiceSettings;
+import com.google.chat.v1.ListSpacesRequest;
+import com.google.chat.v1.Space;
+import com.google.protobuf.util.JsonFormat;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.Collections;
+import java.util.Date;
+import java.util.List;
+
+/* class to demonstrate use of Google Chat API spaces list API */
+public class ChatQuickstart {
+  /** Directory to store authorization tokens for this application. */
+  private static final String TOKENS_DIRECTORY_PATH = "tokens";
+
+  /**
+   * Global instance of the scopes required by this quickstart. If modifying these scopes, delete
+   * your previously saved tokens/ folder.
+   */
+  private static final List<String> SCOPES =
+      Collections.singletonList("https://www.googleapis.com/auth/chat.spaces.readonly");
+
+  /** Global instance of the JSON factory. */
+  private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
+
+  private static final String CREDENTIALS_FILE_PATH = "/credentials.json";
+
+  /**
+   * Run the OAuth2 flow for local/installed app.
+   *
+   * @return An authorized Credential object.
+   * @throws IOException If the credentials.json file cannot be found.
+   */
+  private static Credentials getCredentials() throws Exception {
+    // Load client secrets.
+    InputStream credentialsFileInputStream =
+        ChatQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
+    if (credentialsFileInputStream == null) {
+      throw new FileNotFoundException("Credentials file resource not found.");
+    }
+    GoogleClientSecrets clientSecrets =
+        GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(credentialsFileInputStream));
+
+    // Set up authorization code flow.
+    GoogleAuthorizationCodeFlow flow =
+        new GoogleAuthorizationCodeFlow.Builder(
+                GoogleNetHttpTransport.newTrustedTransport(), JSON_FACTORY, clientSecrets, SCOPES)
+            // Set these two options to generate refresh token alongside access token.
+            .setDataStoreFactory(new FileDataStoreFactory(new File(TOKENS_DIRECTORY_PATH)))
+            .setAccessType("offline")
+            .build();
+
+    // Authorize.
+    Credential credential =
+        new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
+
+    // Build and return an authorized Credential object
+    AccessToken accessToken =
+        new AccessToken(
+            credential.getAccessToken(),
+            new Date(
+                // put the actual expiry date of access token here
+                System.currentTimeMillis()));
+    return UserCredentials.newBuilder()
+        .setAccessToken(accessToken)
+        .setRefreshToken(credential.getRefreshToken())
+        .setClientId(clientSecrets.getInstalled().getClientId())
+        .setClientSecret(clientSecrets.getInstalled().getClientSecret())
+        .build();
+  }
+
+  public static void main(String... args) throws Exception {
+    // Override default service settings to supply user credentials.
+    Credentials credentials = getCredentials();
+
+    // Create the ChatServiceSettings with the credentials
+    ChatServiceSettings chatServiceSettings =
+        ChatServiceSettings.newBuilder()
+            .setCredentialsProvider(FixedCredentialsProvider.create(credentials))
+            .build();
+
+    try (ChatServiceClient chatServiceClient = ChatServiceClient.create(chatServiceSettings)) {
+      ListSpacesRequest request =
+          ListSpacesRequest.newBuilder()
+              // Filter spaces by space type (SPACE or GROUP_CHAT or
+              // DIRECT_MESSAGE).
+              .setFilter("spaceType = \"SPACE\"")
+              .build();
+
+      // Iterate over results and resolve additional pages automatically.
+      for (Space response : chatServiceClient.listSpaces(request).iterateAll()) {
+        System.out.println(JsonFormat.printer().print(response));
+      }
+    }
+  }
+}
+// [END chat_quickstart]