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我正在尝试将 Astyanax 用于带有 Java 的 Cassandra。我在https://github.com/Netflix/astyanax/wiki/Getting-Started尝试了这个例子。我有我刚刚从这个链接复制的代码：

package def;

import com.netflix.astyanax.AstyanaxContext;
import com.netflix.astyanax.Keyspace;
import com.netflix.astyanax.MutationBatch;
import com.netflix.astyanax.connectionpool.NodeDiscoveryType;
import com.netflix.astyanax.connectionpool.OperationResult;
import com.netflix.astyanax.connectionpool.exceptions.ConnectionException;
import com.netflix.astyanax.connectionpool.impl.ConnectionPoolConfigurationImpl;
import com.netflix.astyanax.connectionpool.impl.CountingConnectionPoolMonitor;
import com.netflix.astyanax.impl.AstyanaxConfigurationImpl;
import com.netflix.astyanax.model.Column;
import com.netflix.astyanax.model.ColumnFamily;
import com.netflix.astyanax.model.ColumnList;
import com.netflix.astyanax.serializers.StringSerializer;
import com.netflix.astyanax.thrift.ThriftFamilyFactory;

public class sample {

    public static void main(String[] args) throws Exception{
    AstyanaxContext<Keyspace> context = new AstyanaxContext.Builder()
    .forCluster("Test Cluster")
    .forKeyspace("KeyspaceName")
    .withAstyanaxConfiguration(new AstyanaxConfigurationImpl()      
        .setDiscoveryType(NodeDiscoveryType.NONE)
    )
    .withConnectionPoolConfiguration(new ConnectionPoolConfigurationImpl("MyConnectionPool")
        .setPort(9160)
        .setMaxConnsPerHost(10)
        .setSeeds("127.0.0.1:9160")
    )
    .withConnectionPoolMonitor(new CountingConnectionPoolMonitor())
    .buildKeyspace(ThriftFamilyFactory.getInstance());

    context.start();
    Keyspace keyspace = context.getEntity();

    ColumnFamily<String, String> CF_USER_INFO =
              new ColumnFamily<String, String>(
                "Standard1",              // Column Family Name
                StringSerializer.get(),   // Key Serializer
                StringSerializer.get());  // Column Serializer

    // Inserting data
    MutationBatch m = keyspace.prepareMutationBatch();

    m.withRow(CF_USER_INFO, "acct1234")
      .putColumn("firstname", "john", null)
      .putColumn("lastname", "smith", null)
      .putColumn("address", "555 Elm St", null)
      .putColumn("age", 30, null);

    m.withRow(CF_USER_INFO, "acct1234")
      .incrementCounterColumn("loginCount", 1);

    try {
      OperationResult<Void> result = m.execute();
    } catch (ConnectionException e) {
    }

    System.out.println("completed the task!!!");

    OperationResult<ColumnList<String>> result =
              keyspace.prepareQuery(CF_USER_INFO)
                .getKey("Key1")
                .execute();
            ColumnList<String> columns = result.getResult();

            // Lookup columns in response by name 
            int age        = columns.getColumnByName("age").getIntegerValue();
            long counter   = columns.getColumnByName("loginCount").getLongValue();
            String address = columns.getColumnByName("address").getStringValue();

            // Or, iterate through the columns
            for (Column<String> c : result.getResult()) {
              System.out.println(c.getName());
            }
    }

}

但是当我运行它时，我遇到了一个异常：

log4j:WARN No appenders could be found for logger (com.netflix.astyanax.connectionpool.impl.ConnectionPoolMBeanManager).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
completed the task!!!
Exception in thread "main" com.netflix.astyanax.connectionpool.exceptions.BadRequestException: BadRequestException: [host=127.0.0.1(127.0.0.1):9160, latency=0(0), attempts=1] InvalidRequestException(why:Keyspace KeyspaceName does not exist)
    at com.netflix.astyanax.thrift.ThriftConverter.ToConnectionPoolException(ThriftConverter.java:159)
    at com.netflix.astyanax.thrift.ThriftSyncConnectionFactoryImpl$1.execute(ThriftSyncConnectionFactoryImpl.java:119)
    at com.netflix.astyanax.connectionpool.impl.AbstractExecuteWithFailoverImpl.tryOperation(AbstractExecuteWithFailoverImpl.java:52)
    at com.netflix.astyanax.connectionpool.impl.AbstractHostPartitionConnectionPool.executeWithFailover(AbstractHostPartitionConnectionPool.java:229)
    at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1.execute(ThriftColumnFamilyQueryImpl.java:180)
    at def.sample.main(sample.java:68)
Caused by: InvalidRequestException(why:Keyspace KeyspaceName does not exist)
    at org.apache.cassandra.thrift.Cassandra$set_keyspace_result.read(Cassandra.java:4874)
    at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
    at org.apache.cassandra.thrift.Cassandra$Client.recv_set_keyspace(Cassandra.java:489)
    at org.apache.cassandra.thrift.Cassandra$Client.set_keyspace(Cassandra.java:476)
    at com.netflix.astyanax.thrift.ThriftSyncConnectionFactoryImpl$1.execute(ThriftSyncConnectionFactoryImpl.java:109)
    ... 4 more

谁能告诉我这有什么问题？也没有适当的文档可用于此。所以，你能不能帮帮我。甚至给我一些链接，我可以在其中获得更多示例。

4

2 回答 2

3 
why:Keyspace KeyspaceName does not exist

上面的错误是不言自明的。当应用程序连接到 localhost 时，keyspace 不存在。因此，请确保您创建了密钥空间，然后重新运行您的应用程序。

从评论中，我认为您想对此进行调查。摘自线程，

Keyspace 仅用作客户端，不会在 cassandra 上创建 keyspace 或列族。您可以使用 AsytanaxContext.Builder 构建一个 Cluster 接口，通过它您可以实际创建键空间和列族。

此链接中的此单元测试应为您提供有关如何在集群中创建密钥空间的足够信息。

于 2012-06-21T04:25:58.147 回答
0

您编写的代码示例是为了与 localhost 上 127.0.0.1 上正在运行的 Cassandra 服务器实例进行通信。如果您有 Cassandra 在其他地方运行，或者根本没有，那么您需要在执行代码之前安装并设置该服务器环境。

于 2012-06-20T13:04:57.677 回答