How to read schema of a keyspace using java.? - cassandra

Question

I want to read schema of a keyspace in cassandra.
I know that, in Cassandra-cli we can execute following command to get Schema
show schema keyspace1;
But i want to read schema from remote machine using java.
How i can solve this? Plzzz help me....

Answer 1

This one i solved by using thrift client
KsDef keyspaceDefinition = _client.describe_keyspace(_keyspace);
List<CfDef> columnDefinition = keyspaceDefinition.getCf_defs();
Here key space definition contains whole schema details, so from that KsDef we can read whatever we want. In my case i want to read metadata so i am reading column metadata from the above column definitions as shown below.
for(int i=0;i<columnDefinition.size();i++){
List<ColumnDef> columnMetadata = columnDefinition.get(i).getColumn_metadata();
for(int j=0;j<columnMetadata.size();j++){
columnfamilyNames.add(columnDefinition.get(i).getName());
columnNames.add(new String((columnMetadata.get(j).getName())));
validationClasses.add(columnMetadata.get(j).getValidation_class());
//ar.add(coldef.get(i).getName()+"\t"+bb_to_str(colmeta.get(j).getName())+"\t"+colmeta.get(j).getValidationClass());
}
}
here columnfamilyNames, columnNames and validationClasses are arraylists.