我刚开始使用 Kafka,我能够通过命令提示符生成和使用数据,甚至可以从远程服务器通过 Java 代码生成数据。
但我正在尝试这个简单的消费者 Java 代码,但它不起作用。
public class Simpleconsumer {
private final ConsumerConnector consumer;
private final String topic;
public Simpleconsumer(String topic) {
Properties props = new Properties();
props.put("zookeeper.connect", "127.0.0.1:2181");
props.put("group.id", "topic1");
props.put("auto.offset.reset", "smallest");
consumer = Consumer.createJavaConsumerConnector(new ConsumerConfig(props));
this.topic = topic;
}
public void testConsumer() {
try{
Map<String, Integer> topicCount = new HashMap<String, Integer>();
topicCount.put(topic, 1);
Map<String, List<KafkaStream<byte[], byte[]>>> consumerStreams = consumer.createMessageStreams(topicCount);
List<KafkaStream<byte[], byte[]>> streams = consumerStreams.get(topic);
System.out.println("start.......");
for (final KafkaStream stream : streams) {
ConsumerIterator<byte[], byte[]> it = stream.iterator();
System.out.println("iterate.......");
while (it.hasNext()) {
System.out.println("Message from Single Topic: " + new String(it.next().message()));
}
}
System.out.println("end.......");
if (consumer != null) {
consumer.shutdown();
}
}
catch(Exception e)
{
System.out.println(e);
}
}
public static void main(String[] args) {
// String topic = args[0];
Simpleconsumer simpleHLConsumer = new Simpleconsumer("topic1");
simpleHLConsumer.testConsumer();
}
}
输出是: -
log4j:WARN No appenders could be found for logger (kafka.utils.VerifiableProperties).
log4j:WARN Please initialize the log4j system properly.
start.......
iterate.......
没有错误,程序没有终止或给出任何输出!!
动物园管理员日志
2016-02-18 17:31:31,790 [myid:] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxnFactory@197] - Accepted socket connection from /127.0.0.1:33338
2016-02-18 17:31:31,793 [myid:] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:ZooKeeperServer@868] - Client attempting to establish new session at /127.0.0.1:33338
2016-02-18 17:31:31,821 [myid:] - INFO [SyncThread:0:ZooKeeperServer@617] - Established session 0x152f4265b0b0009 with negotiated timeout 6000 for client /127.0.0.1:33338
2016-02-18 17:31:31,891 [myid:] - INFO [ProcessThread(sid:0 cport:-1)::PrepRequestProcessor@645] - Got user-level KeeperException when processing sessionid:0x152f4265b0b0009 type:create cxid:0x1 zxid:0x718 txntype:-1 reqpath:n/a Error Path:/consumers Error:KeeperErrorCode = NodeExists for /consumers
2016-02-18 17:31:31,892 [myid:] - INFO [ProcessThread(sid:0 cport:-1)::PrepRequestProcessor@645] - Got user-level KeeperException when processing sessionid:0x152f4265b0b0009 type:create cxid:0x2 zxid:0x719 txntype:-1 reqpath:n/a Error Path:/consumers/artinew Error:KeeperErrorCode = NodeExists for /consumers/artinew
2016-02-18 17:31:31,892 [myid:] - INFO [ProcessThread(sid:0 cport:-1)::PrepRequestProcessor@645] - Got user-level KeeperException when processing sessionid:0x152f4265b0b0009 type:create cxid:0x3 zxid:0x71a txntype:-1 reqpath:n/a Error Path:/consumers/artinew/ids Error:KeeperErrorCode = NodeExists for /consumers/artinew/ids
2016-02-18 17:31:32,000 [myid:] - INFO [SessionTracker:ZooKeeperServer@347] - Expiring session 0x152f4265b0b0008, timeout of 6000ms exceeded
2016-02-18 17:31:32,000 [myid:] - INFO [ProcessThread(sid:0 cport:-1)::PrepRequestProcessor@494] - Processed session termination for sessionid: 0x152f4265b0b0008
2016-02-18 17:31:32,002 [myid:] - INFO [SyncThread:0:NIOServerCnxn@1007] - Closed socket connection for client /127.0.0.1:33337 which had sessionid 0x152f4265b0b0
我在 Kafka 控制台中无限循环地得到这个。请解释
[2016-02-17 20:50:08,594] INFO Closing socket connection to /xx.xx.xx.xx. (kafka.network.Processor)
[2016-02-17 20:50:08,174] INFO Closing socket connection to /xx.xx.xx.xx. (kafka.network.Processor)
[2016-02-17 20:50:08,385] INFO Closing socket connection to /xx.xx.xx.xx. (kafka.network.Processor)
[2016-02-17 20:50:08,760] INFO Closing socket connection to /xx.xx.xx.xx. (kafka.network.Processor)
我以以下方式创建了主题
bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 5 --topic topic1
我可以在命令提示符下使用它
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --from-beginning --topic topic1
无法理解是什么问题。