Pub/Sub 订阅主题

演示如何订阅主题并使用 Pub/Sub 解析从 Cloud Functions 收到的事件。

代码示例

Java

如需向 Cloud Run functions 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

import com.google.cloud.functions.BackgroundFunction;
import com.google.cloud.functions.Context;
import functions.eventpojos.PubsubMessage;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.logging.Logger;

public class SubscribeToTopic implements BackgroundFunction<PubsubMessage> {
  private static final Logger logger = Logger.getLogger(SubscribeToTopic.class.getName());

  @Override
  public void accept(PubsubMessage message, Context context) {
    if (message.getData() == null) {
      logger.info("No message provided");
      return;
    }

    String messageString = new String(
        Base64.getDecoder().decode(message.getData().getBytes(StandardCharsets.UTF_8)),
        StandardCharsets.UTF_8);
    logger.info(messageString);
  }
}

Node.js

如需向 Cloud Run functions 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

/**
 * Triggered from a message on a Cloud Pub/Sub topic.
 *
 * @param {object} pubsubMessage The Cloud Pub/Sub Message object.
 * @param {string} pubsubMessage.data The "data" property of the Cloud Pub/Sub Message.
 */
exports.subscribe = pubsubMessage => {
  // Print out the data from Pub/Sub, to prove that it worked
  console.log(Buffer.from(pubsubMessage.data, 'base64').toString());
};

Python

如需向 Cloud Run functions 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

# Triggered from a message on a Cloud Pub/Sub topic.
def subscribe(event, context):
    # Print out the data from Pub/Sub, to prove that it worked
    print(base64.b64decode(event["data"]))

后续步骤

如需搜索和过滤其他 Google Cloud 产品的代码示例，请参阅Google Cloud 示例浏览器。