How to exit while(true) loop in Kafka Consumer-CodePudding

I'm trying to write kafka consumer on .NET 6 I've created a basic consumer class like this.

public List<KafkaCdrModel> Consume(string topic)
        {
            List<KafkaCdrModel> result = new();
            var config = new ConsumerConfig
            {
                GroupId = consumerSettings.GroupId,
                BootstrapServers = consumerSettings.BootstrapServers,
                AutoOffsetReset = AutoOffsetReset.Earliest,
            };

            using var consumer = new ConsumerBuilder<string, string>(config).Build();
            consumer.Subscribe(topic);
            try
            {
                while (true)
                {
                    try
                    {
                        var consumeResult = consumer.Consume();
                        var serializedResult = JsonConvert.DeserializeObject<KafkaCdrModel>(consumeResult.Message.Value);
                        result.Add(serializedResult);
                    }
                    catch (ConsumeException ex)
                    {
                        Console.WriteLine($"Error occured: {ex.Error.Reason}");
                    }
                }

            }
            catch (OperationCanceledException)
            {
                consumer.Close();
            }
            return result;
        }

When I first consumed, the records came, but when there were no more records, it got stuck in the while loop. When I changed the Group Id and tried, I thought that the records would come again, so I would try to serialize it to my custom model. At this moment. I've 2 questions.
First, How can I pull the same records over and over for testing?
Second, How can I get it to exit while loop when it can't find a record?

CodePudding user response：

How can I pull the same records over and over for testing?

R. You need to use a different GroupId. Each KafkaConsumer will consume once every message, but if you use another GroupId it means that are different consumers, and then you can read/consume the same message again.

How can I get it to exit while loop when it can't find a record?

R. Basically, you can use break, example:

int index = 0;
while(true)
{
    index  ;
    if (index >= 2)
        break;
}

You can also see more details in this another question: https://stackoverflow.com/a/6719647/14477325