Google Cloud Function 更新前的状态保存教程

import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.nio.charset.StandardCharsets;

public class CloudFunction {

    private static String myStaticVariable = "Initial Value";
    private static final String BUCKET_NAME = "your-bucket-name"; // 替换为你的 GCS 桶名称
    private static final String OBJECT_NAME = "function-state.txt"; // 替换为你的 GCS 对象名称

    public void handleRequest() {
        // ... 函数逻辑 ...

        // 修改静态变量
        myStaticVariable = "Updated Value: " + System.currentTimeMillis();

        // 保存静态变量到 GCS
        saveStateToGCS();

        // ... 函数逻辑 ...
    }

    private void saveStateToGCS() {
        try {
            Storage storage = StorageOptions.getDefaultInstance().getService();
            BlobId blobId = BlobId.of(BUCKET_NAME, OBJECT_NAME);
            BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("text/plain").build();
            byte[] data = myStaticVariable.getBytes(StandardCharsets.UTF_8);
            storage.create(blobInfo, data);
            System.out.println("State saved to GCS: gs://" + BUCKET_NAME + "/" + OBJECT_NAME);
        } catch (Exception e) {
            System.err.println("Failed to save state to GCS: " + e.getMessage());
            e.printStackTrace();
        }
    }

    // 在函数启动时，从 GCS 加载状态 (可选)
    public static void loadStateFromGCS() {
        try {
            Storage storage = StorageOptions.getDefaultInstance().getService();
            BlobId blobId = BlobId.of(BUCKET_NAME, OBJECT_NAME);
            byte[] content = storage.readAllBytes(blobId);
            myStaticVariable = new String(content, StandardCharsets.UTF_8);
            System.out.println("State loaded from GCS: " + myStaticVariable);
        } catch (Exception e) {
            System.err.println("Failed to load state from GCS: " + e.getMessage());
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        // 模拟函数调用
        CloudFunction function = new CloudFunction();
        // 可选：在启动时加载状态
        // CloudFunction.loadStateFromGCS();
        function.handleRequest();
        function.handleRequest();
    }
}