java - kafka消息发送不出去

import java.util.Properties;

import net.sf.json.JSONObject;
import kafka.javaapi.producer.Producer;
import kafka.javaapi.producer.ProducerData;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;
import kafka.serializer.StringEncoder;

//利用线程池 调用类的静态函数发送消息 但是发布出去 不知道什么原因

public class SendOid2Kafka {
    private static Producer producer = createProducer();
    
    public static void sendMessage2CMS(JSONObject message) {
        producer.send(new KeyedMessage("novel.review.topic", message));
        System.out.println("send");  //执行不到这里 消息没发送出去 
    }

    
    private static Producer createProducer() {
        Properties properties = new Properties();
        properties.put("zookeeper.connect","*");
        properties.put("serializer.class", StringEncoder.class.getName());
        properties.put("metadata.broker.list","*");
        properties.put("zookeeper.session.timeout.ms", "15000");
                                                                                                                                                                                               
        return new Producer(new ProducerConfig(properties));
    }
}

改为发送String 就发送出去了
JSONObject就发送不出去

想发JSONObject怎么办？？？