setThreadingModel() should take String, and setThreadPoolSize() should take long

[bowenli86]

Currently, fromProperties(Properties props) can only recognize boolean, string, and long. While the signature of thread-related methods are setThreadingModel(enum) and setThreadPoolSize(int). Thus, these properties cannot be set via fromProperties(Properties props).

You should change the signature to setThreadingModel(String) and setThreadPoolSize(long).

[bowenli86]

Alternatively, for ThreadPoolSize, add the following code to fromProperties()

else if (type == int.class) {
  method.invoke(config, value);
}

[markglh]

I think this should go further, the KCL is much better at supporting configuration:
https://github.com/awslabs/amazon-kinesis-client/blob/master/src/main/java/com/amazonaws/services/kinesis/clientlibrary/config/KinesisClientLibConfigurator.java#L112

You can set not only primitive types, but the credential providers etc, too. This should be abstracted and shared between the libraries. It makes no sense to have such inconsistency between the two.

A quick (and correct?) fix would be to add support for Int here like you suggested:
https://github.com/awslabs/amazon-kinesis-producer/blob/master/java/amazon-kinesis-producer/src/main/java/com/amazonaws/services/kinesis/producer/KinesisProducerConfiguration.java#L197

And add an additional setter for the ThreadingModel which accepts Strings:

public KinesisProducerConfiguration setThreadingModel(String threadingModel) {
        setThreadingModel(ThreadingModel.valueOf(stringValue))
}

The inconsistent design of these two libraries can be pretty frustrating at times.

[markglh]

Fixed here: #134