無法使用Hector連接到cassandra

Question

我無法使用Hector訪問Casandra。以下是代碼

import java.util.Arrays; 
import java.util.List; 
import me.prettyprint.cassandra.service.CassandraHostConfigurator; 
import me.prettyprint.cassandra.service.ThriftCluster; 
import me.prettyprint.cassandra.service.ThriftKsDef; 
import me.prettyprint.hector.api.Cluster; 
import me.prettyprint.hector.api.Keyspace; 
import me.prettyprint.hector.api.ddl.ColumnFamilyDefinition; 
import me.prettyprint.hector.api.ddl.KeyspaceDefinition; 
import me.prettyprint.hector.api.factory.HFactory; 
import me.prettyprint.hector.api.mutation.Mutator; 

public class Hector { 
public static void main (String[] args){ 
boolean cfExists = false; 
Cluster cluster = HFactory.getOrCreateCluster("mycluster", new      CassandraHostConfigurator("host:9160")); 
Keyspace keyspace = HFactory.createKeyspace("Keyspace1", cluster); 
// first check if the key space exists 
     KeyspaceDefinition keyspaceDetail = cluster.describeKeyspace("Keyspace1"); 
     // if not, create one 
     if (keyspaceDetail == null) { 

      CassandraHostConfigurator cassandraHostConfigurator = new CassandraHostConfigurator("host:9160"); 
      ThriftCluster cassandraCluster = new ThriftCluster("mycluster", cassandraHostConfigurator); 

      ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition("Keyspace1", "base"); 
      cassandraCluster.addKeyspace(new ThriftKsDef("Keyspace1", "org.apache.cassandra.locator.SimpleStrategy", 1, 
        Arrays.asList(cfDef))); 

     } else { 

      // even if the key space exists, we need to check if the column family exists 
      List<ColumnFamilyDefinition> columnFamilyDefinitions = keyspaceDetail.getCfDefs(); 
      for (ColumnFamilyDefinition def : columnFamilyDefinitions) { 
       String columnFamilyName = def.getName(); 
       if (columnFamilyName.equals("tcs_im")) 
        cfExists = true; 
      } 
     } 
} 
} 

遭遇以下錯誤

的log4j：警告沒有附加目的地可以爲記錄器（me.prettyprint.cassandra.connection.CassandraHostRetryService）中找到。 log4j：WARN請正確初始化log4j系統。 log4j：警告有關更多信息，請參見http://logging.apache.org/log4j/1.2/faq.html#noconfig。 線程「main」中的異常java.lang.IllegalAccessError：嘗試訪問me.prettyprint.cassandra.connection.HConnectionManager類中的類me.prettyprint.cassandra.connection.HConnectionManager 。 HConnectionManager.java:78） at me.prettyprint.cassandra.service.AbstractCluster。（AbstractCluster.java:69） at me.prettyprint.cassandra.service.AbstractCluster。（AbstractCluster.java:65） at me.prettyprint。在me.prettyprint.hector.api.factory.HFactory.getOrCreateCluster（）上的文件（HFactory.java:155） at com.im.tcs.Hector.main（Hector.java:20）

請幫助爲什麼發生。

Answer 1

我們使用CassandraConnection類爲方便類：使用

import me.prettyprint.cassandra.connection.DynamicLoadBalancingPolicy; 
import me.prettyprint.cassandra.service.CassandraHostConfigurator; 
import me.prettyprint.cassandra.service.ExhaustedPolicy; 
import me.prettyprint.cassandra.service.OperationType; 
import me.prettyprint.hector.api.Cluster; 
import me.prettyprint.hector.api.HConsistencyLevel; 
import me.prettyprint.hector.api.Keyspace; 
import me.prettyprint.hector.api.factory.HFactory; 

import java.util.HashMap; 
import java.util.Map; 

/** 
* lazy connect 
*/ 
final class CassandraConnection { 

    // Constants ----------------------------------------------------- 

    private static final String HOSTS = "localhost"; 
    private static final int PORT = "9160"; 
    private static final String CLUSTER_NAME = "myCluster"; 
    private static final int TIMEOUT = 500); 
    private static final String KEYSPACE = "Keyspace1"; 
    private static final ConsistencyLevelPolicy CL_POLICY = new ConsistencyLevelPolicy(); 

    // Attributes ---------------------------------------------------- 

    private Cluster cluster; 
    private volatile Keyspace keyspace; 

    // Constructors -------------------------------------------------- 

    CassandraConnection() {} 

    // Methods -------------------------------------------------------- 

    Cluster getCluster() { 
     if (null == cluster) { 
      CassandraHostConfigurator config = new CassandraHostConfigurator(); 
      config.setHosts(HOSTS); 
      config.setPort(PORT); 
      config.setUseThriftFramedTransport(true); 
      config.setUseSocketKeepalive(true); 
      config.setAutoDiscoverHosts(false); 
      // maxWorkerThreads provides the throttling for us. So hector can be let to grow freely... 
      config.setExhaustedPolicy(ExhaustedPolicy.WHEN_EXHAUSTED_GROW); 
      config.setMaxActive(1000); // hack since ExhaustedPolicy doesn't work 
      // suspend hosts if response is unacceptable for web response 
      config.setCassandraThriftSocketTimeout(TIMEOUT); 
      config.setUseHostTimeoutTracker(true); 
      config.setHostTimeoutCounter(3); 
      config.setLoadBalancingPolicy(new DynamicLoadBalancingPolicy()); 

      cluster = HFactory.createCluster(CLUSTER_NAME, config); 

     } 
     return cluster; 
    } 

    Keyspace getKeyspace() { 
     if (null == keyspace) { 
      keyspace = HFactory.createKeyspace(KEYSPACE, getCluster(), CL_POLICY); 
     } 
     return keyspace; 
    } 

    private static class ConsistencyLevelPolicy implements me.prettyprint.hector.api.ConsistencyLevelPolicy { 

     @Override 
     public HConsistencyLevel get(final OperationType op) { 
      return HConsistencyLevel.ONE; 
     } 

     @Override 
     public HConsistencyLevel get(final OperationType op, final String cfName) { 
      return get(op); 
     } 
    } 
} 

例子：

private final CassandraConnection conn = new CassandraConnection(); 

SliceQuery<String, String, String> sliceQuery = HFactory.createSliceQuery(
       conn.getKeyspace(), StringSerializer.get(), StringSerializer.get(), StringSerializer.get()); 
sliceQuery.setColumnFamily("myColumnFamily"); 
sliceQuery.setRange("", "", false, Integer.MAX_VALUE); 
sliceQuery.setKey("myRowKey"); 
ColumnSlice<String, String> columnSlice = sliceQuery.execute().get();