如何在 confluent kafka C# 中读取 GenericRecord 特定数据

Question

这是我尝试读取 Avro 通用记录表单消费者的简单代码片段：

using (var schemaRegistry = new CachedSchemaRegistryClient(new SchemaRegistryConfig { SchemaRegistryUrl = schemaRegistryUrl }))
  using (var consumer = new 
        ConsumerBuilder<string, GenericRecord>(new ConsumerConfig { BootstrapServers = bootstrapServers, GroupId = groupName })
                        .SetKeyDeserializer(new AsyncAvroDeserializer<string>(schemaRegistry).AsSyncOverAsync())
                        .SetValueDeserializer(new AsyncAvroDeserializer<GenericRecord>(schemaRegistry).AsSyncOverAsync())
                        .SetErrorHandler((_, e) => Console.WriteLine($"Error: {e.Reason}"))
                        .Build())
                {
      consumer.Subscribe(topicName);

      try
       {
           while (true)
             {
                try
                 {
                    var consumeResult = consumer.Consume();
                    Console.WriteLine($"Key: {consumeResult.Message.Key}\nValue: {consumeResult.Value}");
                    Console.WriteLine(consumeResult.Value.Schema);
                            Console.WriteLine(consumeResult.Value.Schema["favorite_number"]);

                  }
                 catch (ConsumeException e)
                   {
                       Console.WriteLine($"Consume error: {e.Error.Reason}");
                            }
                        }
                    }
                    catch (OperationCanceledException)
                    {
                        // commit final offsets and leave the group.
                        consumer.Close();
                    }
                }

如您所见，我可以记录架构，但不知道如何获取其数据值。

 Console.WriteLine(consumeResult.Value.Schema);

 Console.WriteLine(consumeResult.Value.Schema["favorite_number"]);

虽然此对象中的模式和数据是这样的consumeResult.Value:

{架构：{"type":"record","name":"User","namespace":"Confluent.Kafka.Examples.AvroSpecific","fields" :[{"name":"name","type":"string"},{"name":"favorite_number","type":["int","null"]},{"name":"favorite_color","type":["string","null"]}]},内容: { 名称: sfs, favorite_number: 41, favorite_color: 蓝色, }}

我想阅读内容数据。

Answer 1

the content is not accessible

我认为 Value.contents 不是您想要的。特别是因为属性是 private，正如你提到的

getter 的定义就像一本字典 - Source code

尝试consumeResult.Value["favorite_number"]

当您执行 consumeResult.Value.Schema["favorite_number"] 时，您会得到架构中的 Field 对象，而不是外部记录中字段的值。 - Source code

如何在 confluent kafka C# 中读取 GenericRecord 特定数据

How to read GenericRecord specific data in confluent kafka C#

c#

avro

apache-kafka

confluent-schema-registry

confluent-platform