java Kafka生产者错误

1 [main] INFO kafka.utils.VerifiableProperties - Verifying properties
28 [main] INFO kafka.utils.VerifiableProperties - Property      metadata.broker.list is overridden to xxxxxx:9092
28 [main] INFO kafka.utils.VerifiableProperties - Property serializer.class is overridden to kafka.serializer.StringEncoder
137 [main] INFO kafka.client.ClientUtils$- Fetching metadata from broker id:0,host: xxxxxx,port:9092 with correlation id 0 for 1 topic(s) Set(words_topic)
189 [main] ERROR kafka.producer.SyncProducer - Producer connection to xxxxxx:9092 unsuccessful
198 [main] WARN kafka.client.ClientUtils$- Fetching topic metadata with correlation id 0 for topics [Set(words_topic)] from broker [id:0,port:9092] failed
199 [main] ERROR kafka.utils.Utils$- fetching topic metadata for topics [Set(words_topic)] from broker [ArrayBuffer(id:0,port:9092)] failed

它是kafka控制台

[2015-01-27 05:23:33,767] DEBUG Accepted connection from /xxxxx on /xxxx:9092. sendBufferSize [actual|requested]: [212992|1048576] recvBufferSize [actual|requested]: [212992|1048576] (kafka.network.Acceptor)
[2015-01-27 05:23:33,767] DEBUG Processor 1 listening to new connection from /xxxx:65307 (kafka.network.Processor)
[2015-01-27 05:23:33,872] INFO Closing socket connection to /xxxx. (kafka.network.Processor)
[2015-01-27 05:23:33,873] DEBUG Closing connection from /xxxx:65307 (kafka.network.Processor)

这是我的代码.

Properties props = new Properties();
    props.put("metadata.broker.list","?????:9092");
    props.put("serializer.class","kafka.serializer.StringEncoder");
    ProducerConfig config = new ProducerConfig(props);
    Producer<String,String> producer = new Producer<String,String>(config);

    // Now we break each word from the paragraph
        for (String word :
            METAMORPHOSIS_OPENING_PARA.split("s")) {
        // Create message to be sent to "words_topic" topic with the word
        KeyedMessage<String,String> data =
                new KeyedMessage<String,String>
                        ("words_topic",word);
        // Send the message
        producer.send(data);
    }
    System.out.println("Produced data");
    // close the producer
    producer.close();

}

// First paragraph from Franz Kafka's Metamorphosis
private static String METAMORPHOSIS_OPENING_PARA =
        "One morning,when Gregor Samsa woke from troubled dreams,"
                + "he found himself transformed in his bed into a horrible "
                + "vermin. He lay on his armour-like back,and if he lifted "
                + "his head a little he could see his brown belly,slightly "
                + "domed and divided by arches into stiff sections.";