使用Apache Cassandra 1.0的Java驱动程序连接Cassandra时出现错误，来自com.example.cassandra。

使用DataStax的Cassandra Java驱动程序连接Cassandra客户端时，会引发以下错误：

Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: [/127.0.0.1])

请提供建议...

谢谢！

我的Java代码如下：

package com.example.cassandra;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Host;
import com.datastax.driver.core.Metadata;

public class SimpleClient {

private Cluster cluster;

public void connect(String node){

    cluster = Cluster.builder().addContactPoint(node).build();
    Metadata metadata = cluster.getMetadata();
    System.out.println(metadata.getClusterName());
}   


public void close()
{
cluster.shutdown();
}

public static void main(String args[]) {

SimpleClient client = new SimpleClient();
client.connect("127.0.0.1");
client.close();
}