我对cassandra和hector还是陌生的，并试图创建一个超级列。我已经做了很多研究，但是到目前为止，仍然没有任何效果。在研究stackoverflow时，我发现了这个问题here，这对我似乎很有帮助。因此，我尝试为示例插入代码，但出现异常。
这是我的代码（如果有hector，应该是可复制/可粘贴的）-很抱歉，它可能无法完美读取，在询问以下内容之前，我做了很多尝试和尝试：
import java.util.Arrays;
import me.prettyprint.cassandra.serializers.StringSerializer;
import me.prettyprint.cassandra.service.ThriftKsDef;
import me.prettyprint.cassandra.service.template.SuperCfTemplate;
import me.prettyprint.cassandra.service.template.SuperCfUpdater;
import me.prettyprint.cassandra.service.template.ThriftSuperCfTemplate;
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.ComparatorType;
import me.prettyprint.hector.api.ddl.KeyspaceDefinition;
import me.prettyprint.hector.api.factory.HFactory;
public class DatabaseDataImporter {
private Cluster myCluster;
private KeyspaceDefinition keyspaceDefinition;
private Keyspace keyspace;
private SuperCfTemplate<String, String, String> template;
final static StringSerializer ss = StringSerializer.get();
public DatabaseDataImporter() {
initializeCluster();
SuperCfTemplate<String, String, String> template = new ThriftSuperCfTemplate<String, String, String>(
keyspace, "Nodes", ss, ss, ss);
SuperCfUpdater<String, String, String> updater = template
.createUpdater("key", "newcf");
updater.setString("subname", "1");
template.update(updater);
}
private void initializeCluster() {
// get Cluster
myCluster = HFactory.getOrCreateCluster("Test Cluster",
"localhost:9160");
keyspaceDefinition = myCluster.describeKeyspace("Graphs");
// If keyspace does not exist, the CFs don't exist either. => create
// them.
if (keyspaceDefinition == null) {
createSchema();
}
keyspace = HFactory.createKeyspace("Graphs", myCluster);
}
private void createSchema() {
// get Cluster
Cluster myCluster = HFactory.getOrCreateCluster("Test Cluster",
"localhost:9160");
// add Schema
int replicationFactor = 1;
ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition(
"Graphs", "Nodes", ComparatorType.BYTESTYPE);
KeyspaceDefinition newKeyspace = HFactory.createKeyspaceDefinition(
"Graphs", ThriftKsDef.DEF_STRATEGY_CLASS, replicationFactor,
Arrays.asList(cfDef));
// Add the schema to the cluster.
// "true" as the second param means that Hector will block until all
// nodes see the change.
myCluster.addKeyspace(newKeyspace, true);
}
public static void main(String[] args) {
new DatabaseDataImporter();
}
}
我得到的异常是：
Exception in thread "main" me.prettyprint.hector.api.exceptions.HInvalidRequestException: InvalidRequestException(why:supercolumn parameter is invalid for standard CF Nodes)
at me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:52)
at me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:260)
at me.prettyprint.cassandra.model.ExecutingKeyspace.doExecuteOperation(ExecutingKeyspace.java:113)
at me.prettyprint.cassandra.model.MutatorImpl.execute(MutatorImpl.java:243)
at me.prettyprint.cassandra.service.template.AbstractColumnFamilyTemplate.executeBatch(AbstractColumnFamilyTemplate.java:115)
at me.prettyprint.cassandra.service.template.AbstractColumnFamilyTemplate.executeIfNotBatched(AbstractColumnFamilyTemplate.java:159)
at me.prettyprint.cassandra.service.template.SuperCfTemplate.update(SuperCfTemplate.java:203)
at algorithms.DatabaseDataImporter.<init>(DatabaseDataImporter.java:43)
at algorithms.DatabaseDataImporter.main(DatabaseDataImporter.java:87)
Caused by: InvalidRequestException(why:supercolumn parameter is invalid for standard CF Nodes)
at org.apache.cassandra.thrift.Cassandra$batch_mutate_result.read(Cassandra.java:20833)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
at org.apache.cassandra.thrift.Cassandra$Client.recv_batch_mutate(Cassandra.java:964)
at org.apache.cassandra.thrift.Cassandra$Client.batch_mutate(Cassandra.java:950)
at me.prettyprint.cassandra.model.MutatorImpl$3.execute(MutatorImpl.java:246)
at me.prettyprint.cassandra.model.MutatorImpl$3.execute(MutatorImpl.java:243)
at me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:104)
at me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:253)
... 7 more
我可以理解，我以某种方式做了一件坏事，因为我试图在标准列家族中插入一个超级列。 （其来源为here）。因此，也许这是在创建过程中一切都被破坏的代码：
ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition(
"Graphs", "Nodes", ComparatorType.BYTESTYPE);
这就是我不知道如何进行的地方。我试图找到一个“ SuperColumnFamilyDefinition”类，但找不到。您对我的代码修改有什么想法或建议吗？我会很高兴的。
非常感谢您与我分享的每一个想法。
最佳答案
我找到了问题的答案，并希望与他人分享（也许以后会对某人有所帮助）。我认为解决方案非常简单。
ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition(
"Graphs", "Nodes", ComparatorType.BYTESTYPE);
需要扩展到
ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition(
"Graphs", "Nodes", ComparatorType.BYTESTYPE);
// defines it as super column
((ThriftCfDef) cfDef).setColumnType(ColumnType.SUPER);