http://hector-client.github.com/hector/build/html/content/HOM/hector-object-mapper.html をやってみる。そのままある程度はドキュメント通りに

pom.xml

<dependency>
  <groupId>org.hectorclient</groupId>
  <artifactId>hector-object-mapper</artifactId>
  <version>3.1-06</version>
</dependency>

を追加しておく

Sample.java

package sample;

import javax.persistence.Entity;
import javax.persistence.Table;

import me.prettyprint.hom.annotations.Column;
import me.prettyprint.hom.annotations.Id;

@Entity
@Table(name="Sample")
public class Sample {

    @Id
    private String key;

    @Column(name = "name")
    private String name;

    @Column(name = "color", converter = Color.ColorConverter.class)
    private Color color;

    public void setKey(String key) {
        this.key = key;
    }

    public String getKey() {
        return key;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setColor(Color color) {
        this.color = color;
    }

    public Color getColor() {
        return color;
    }
}

Color.java

package sample;

import me.prettyprint.hom.PropertyMappingDefinition;
import me.prettyprint.hom.converters.Converter;

public class Color {

    private String color;

    public Color(String color) {
        this.color = color;
    }

    public String getColor() {
        return color;
    }

    public static class ColorConverter implements Converter<Color> {

        @Override
        public Color convertCassTypeToObjType(PropertyMappingDefinition def, byte[] value) {
            return new Color(new String(value));
        }

        @Override
        public byte[] convertObjTypeToCassType(Color color) {
            return color.getColor().getBytes();
        }
    }
}

me.prettyprint.hom.converters.Converterを使ってCassandraに突っ込む際や取ってくる際にシリアライズしたりできるので、これを使ってクラスの状態を突っ込むことができる模様。公式ドキュメントではcom.real.hom.converters.Converterってなってますけど

HectorClient.java

import sample.Color;
import sample.Sample;
import me.prettyprint.hector.api.Cluster;
import me.prettyprint.hector.api.Keyspace;
import me.prettyprint.hector.api.factory.HFactory;
import me.prettyprint.hom.EntityManagerImpl;

public class HectorClient2 {

    private static long time;

    public static void main(String[] args) {
        Cluster cluster = HFactory.getOrCreateCluster("Test Cluster", "127.0.0.1");
        Keyspace keyspace = HFactory.createKeyspace("sample", cluster);

        EntityManagerImpl em = new EntityManagerImpl(keyspace, "sample");

        putSample(em);

        Sample sample = em.find(Sample.class, String.valueOf(time));

        System.out.println(sample.getName());
        System.out.println(sample.getColor().getColor());

        cluster.getConnectionManager().shutdown();
    }

    public static void putSample(EntityManagerImpl em) {
        time = System.currentTimeMillis();

        Sample sample = new Sample();
        sample.setKey(String.valueOf(time));
        sample.setName("hoge");
        sample.setColor(new Color("red"));

        em.persist(sample);
    }
}

実行後にcassandra-cliからlistしてみると

RowKey: 1348241491638
=> (column=color, value=red, timestamp=1348241491656000)
=> (column=name, value=hoge, timestamp=1348241491647000)

setColorしたオブジェクトでもConverterを介してconvertObjTypeToCassTypeで介したデータがぶち込まれる