回滚到架构修订版本

回滚到架构修订版本

深入探索

如需查看包含此代码示例的详细文档，请参阅以下内容：

• 回滚架构修订版本

代码示例

C++

试用此示例之前，请按照 Pub/Sub 快速入门：使用客户端库中的 C++ 设置说明进行操作。如需了解详情，请参阅 Pub/Sub C++ API 参考文档。

要向 Pub/Sub 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

namespace pubsub = ::google::cloud::pubsub;
[](pubsub::SchemaServiceClient client, std::string const& project_id,
   std::string const& schema_id, std::string const& revision_id) {
  google::pubsub::v1::RollbackSchemaRequest request;
  request.set_name(pubsub::Schema(project_id, schema_id).FullName());
  request.set_revision_id(revision_id);
  auto schema = client.RollbackSchema(request);
  if (!schema) throw std::move(schema).status();

  std::cout << "Rolledback schema. Created a new schema and its metadata is:"
            << "\n"
            << schema->DebugString() << "\n";
}

C#

试用此示例之前，请按照 Pub/Sub 快速入门：使用客户端库中的 C# 设置说明进行操作。如需了解详情，请参阅 Pub/Sub C# API 参考文档。

要向 Pub/Sub 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

using Google.Cloud.PubSub.V1;

public class RollbackSchemaSample
{
    public void RollbackSchema(string projectId, string schemaId, string revisionId)
    {
        SchemaServiceClient schemaService = SchemaServiceClient.Create();
        SchemaName schemaName = SchemaName.FromProjectSchema(projectId, schemaId);
        schemaService.RollbackSchema(schemaName, revisionId);
    }
}

Go

试用此示例之前，请按照 Pub/Sub 快速入门：使用客户端库中的 Go 设置说明进行操作。如需了解详情，请参阅 Pub/Sub Go API 参考文档。

要向 Pub/Sub 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/pubsub"
)

// rollbackSchema creates a new schema revision that is a copy of the provided revisionID.
func rollbackSchema(w io.Writer, projectID, schemaID, revisionID string) error {
	// projectID := "my-project-id"
	// schemaID := "my-schema"
	// revisionID := "a1b2c3d4"
	ctx := context.Background()
	client, err := pubsub.NewSchemaClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("pubsub.NewSchemaClient: %w", err)
	}
	defer client.Close()

	s, err := client.RollbackSchema(ctx, schemaID, revisionID)
	if err != nil {
		return fmt.Errorf("RollbackSchema: %w", err)
	}
	fmt.Fprintf(w, "Rolled back a schema: %#v\n", s)
	return nil
}

Java

试用此示例之前，请按照 Pub/Sub 快速入门：使用客户端库中的 Java 设置说明进行操作。如需了解详情，请参阅 Pub/Sub Java API 参考文档。

要向 Pub/Sub 进行身份验证，请设置应用默认凭据。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.api.gax.rpc.NotFoundException;
import com.google.cloud.pubsub.v1.SchemaServiceClient;
import com.google.pubsub.v1.Schema;
import com.google.pubsub.v1.SchemaName;
import java.io.IOException;

public class RollbackSchemaExample {

  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project";
    String schemaId = "your-schema";
    String revisionId = "your-revision";

    rollbackSchemaExample(projectId, schemaId, revisionId);
  }

  public static void rollbackSchemaExample(String projectId, String schemaId, String revisionId)
      throws IOException {
    SchemaName schemaName = SchemaName.of(projectId, schemaId);

    try (SchemaServiceClient schemaServiceClient = SchemaServiceClient.create()) {

      Schema schema = schemaServiceClient.rollbackSchema(schemaName, revisionId);

      System.out.println("Rolled back a schema:" + schema);

    } catch (NotFoundException e) {
      System.out.println(schemaName + "not found.");
    }
  }
}

Node.js

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const schemaNameOrId = 'YOUR_SCHEMA_NAME_OR_ID';
// const revisionId = 'YOUR_REVISION_ID';

// Imports the Google Cloud client library
const {PubSub} = require('@google-cloud/pubsub');

// Creates a client; cache this for further use
const pubSubClient = new PubSub();

async function rollbackSchema(schemaNameOrId, revisionId) {
  // Get the fully qualified schema name.
  const schema = pubSubClient.schema(schemaNameOrId);
  const name = await schema.getName();

  // Use the gapic client to roll back the schema revision.
  const schemaClient = await pubSubClient.getSchemaClient();
  await schemaClient.rollbackSchema({
    name,
    revisionId,
  });

  console.log(`Schema ${name} revision ${revisionId} rolled back.`);
}

Node.js

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const schemaNameOrId = 'YOUR_SCHEMA_NAME_OR_ID';
// const revisionId = 'YOUR_REVISION_ID';

// Imports the Google Cloud client library
import {PubSub} from '@google-cloud/pubsub';

// Creates a client; cache this for further use
const pubSubClient = new PubSub();

async function rollbackSchema(schemaNameOrId: string, revisionId: string) {
  // Get the fully qualified schema name.
  const schema = pubSubClient.schema(schemaNameOrId);
  const name = await schema.getName();

  // Use the gapic client to roll back the schema revision.
  const schemaClient = await pubSubClient.getSchemaClient();
  await schemaClient.rollbackSchema({
    name,
    revisionId,
  });

  console.log(`Schema ${name} revision ${revisionId} rolled back.`);
}

Python

试用此示例之前，请按照 Pub/Sub 快速入门：使用客户端库中的 Python 设置说明进行操作。如需了解详情，请参阅 Pub/Sub Python API 参考文档。

要向 Pub/Sub 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

from google.api_core.exceptions import NotFound
from google.cloud.pubsub import SchemaServiceClient

# TODO(developer): Replace these variables before running the sample.
# project_id = "your-project-id"
# schema_id = "your-schema-id"
# schema_revision_id = "your-schema-revision-id"

schema_client = SchemaServiceClient()
schema_path = schema_client.schema_path(project_id, schema_id)

try:
    result = schema_client.rollback_schema(
        request={"name": schema_path, "revision_id": schema_revision_id}
    )
    print(f"Rolled back a schema revision:\n{result}")
except NotFound:
    print(f"{schema_id} not found.")

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。