bulkinserter.java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.UUID;

import org.apache.cassandra.db.marshal.AsciiType;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.cassandra.dht.Murmur3Partitioner;
import org.apache.cassandra.io.sstable.SSTableSimpleUnsortedWriter;

import static org.apache.cassandra.utils.ByteBufferUtil.bytes;
import static org.apache.cassandra.utils.UUIDGen.decompose;

/**
 *
 * @author davide
 */
public class CassandraBulkInserter
{
    static String filename;

    public static void main(String[] args) throws IOException
    {   
        if (args.length == 0)
        {
            System.out.println("Expecting <csv_file> as argument");
            System.exit(1);
        }
        filename = args[0];

        String keyspace = "demo";
        File directory = new File(keyspace);
        if (!directory.exists()) {
            directory.mkdir();
        }

        BufferedReader reader = new BufferedReader(new FileReader(filename));
        
        IPartitioner partitioner = new Murmur3Partitioner();
        SSTableSimpleUnsortedWriter usersWriter = new SSTableSimpleUnsortedWriter(
                directory,
                partitioner,
                keyspace,
                "users",
                AsciiType.instance,
                null,
                64);

        String line;
        int lineNumber = 0;
        CsvEntry entry = new CsvEntry();
        // There is no reason not to use the same timestamp for every column in that example.
        long timestamp = System.currentTimeMillis() * 1000;
        while ( (line = reader.readLine()) != null )
        {
            if (entry.parse(line, lineNumber))
            {
                System.out.println(lineNumber + ": " + entry);
                
                ByteBuffer uuid = ByteBuffer.wrap(decompose(entry.key));
                                
                usersWriter.newRow(uuid);
                // usersWriter.addColumn(bytes("id"), uuid, timestamp);
                usersWriter.addColumn(bytes("firstname"), bytes(entry.firstname), timestamp);
                usersWriter.addColumn(bytes("lastname"), bytes(entry.lastname), timestamp);
                usersWriter.addColumn(bytes("password"), bytes(entry.password), timestamp);
                usersWriter.addColumn(bytes("age"), bytes(entry.age), timestamp);
                usersWriter.addColumn(bytes("email"), bytes(entry.email), timestamp);

            }
            lineNumber++;
        }
        
        // Don't forget to close!
        usersWriter.close();
        reader.close();
        System.exit(0);
    }
    
    static class CsvEntry
    {
        UUID key;
        String firstname;
        String lastname;
        String password;
        long age;
        String email;

        @Override
        public String toString() {
            return key.toString() +" : {firstname = " + firstname +
                    ", lastname = " + lastname +
                    ", password = " + password +
                    ", age = " + age +
                    ", email = " + email + "}";
        }
        
        boolean parse(String line, int lineNumber)
        {
            String[] columns = line.split(",");
            // System.out.println(columns.length);
            
            // Ghetto csv parsing
            if (columns.length != 5)
            {
                System.out.println(
                        String.format("Invalid input at line %d of %s",
                        lineNumber, filename));
                return false;
            }
            
            try
            {
                key = UUID.randomUUID();
                firstname = columns[0].trim();
                lastname = columns[1].trim();
                password = columns[2].trim();
                age = Long.parseLong(columns[3].trim());
                email = columns[4].trim();
                return true;
            }
            catch (NumberFormatException e)
            {
                System.out.println(
                        String.format("Invalid number in input at line %d of %s",
                        lineNumber, filename));
                System.out.println(e.getMessage());
                return false;
            }
        }
    }
}

data.csv

ddl.cql3

create keyspace demo 
with replication = {'class' : 'SimpleStrategy', 'replication_factor' : 1 };

use demo

create table users (
    id uuid primary key,
    firstname varchar,
    lastname varchar,
    password varchar,
    age int,
    email varchar)
with compact storage 
and compaction = {'class' : 'LeveledCompactionStrategy' };