Database Reference
In-Depth Information
recompile the project. In this simple example, the
Properties
object is
constructed. These
Properties
are then passed to the constructor of the
ProducerConfig
object:
public static void
main(String[] args)
throws
Exception {
Properties props =
new
Properties();
props.put("metadata.broker.list",
"localhost:6001,localhost:6002,localhost:6003");
props.put("serializer.class",
"kafka.serializer.StringEncoder");
props.put("request.required.acks", "1");
ProducerConfig config =
new
ProducerConfig(props);
This configuration object is then passed on to the Producer object, which
takes a type for both its
Key
and its
Message
type. Although the Key is
generally optional, it is important that the
serializer.class
defined in
the configuration properties can successfully encode the objects used for the
Key
and the
Message
. In this case, Strings are being used for both
Key
and
Message
:
String topic = args[0];
Producer<String,String> producer = new
Producer<String,String>(config);
This simple example reads lines from the console and sends them to Kafka.
The Producer itself takes
KeyedMessage
objects either singly or as part of
a List collection. These messages are constructed with a topic, a key, and a
message. If the key is not required, only the topic and the message can be
used as in this example:
BufferedReader reader =
new
BufferedReader(
new
InputStreamReader(System.
in
));
while
(reader.ready()) {
String toSend = reader.readLine();
producer.send(
new
KeyedMessage<String,String>(topic,
toSend));
}
