我想在spark job中使用kryo序列化。

public class SerializeTest {

    public static class Toto implements Serializable {
        private static final long serialVersionUID = 6369241181075151871L;
        private String a;

        public String getA() {
            return a;
        }

        public void setA(String a) {
            this.a = a;
        }
    }

    private static final PairFunction<Toto, Toto, Integer> WRITABLE_CONVERTOR = new PairFunction<Toto, Toto, Integer>() {
        private static final long serialVersionUID = -7119334882912691587L;

        @Override
        public Tuple2<Toto, Integer> call(Toto input) throws Exception {
            return new Tuple2<Toto, Integer>(input, 1);
        }
    };

    public static void main(String[] args) {
        SparkConf conf = new SparkConf().setAppName("SerializeTest");
        conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
        conf.registerKryoClasses(new Class<?>[]{Toto[].class});
        JavaSparkContext context = new JavaSparkContext(conf);

        List<Toto> list = new ArrayList<Toto>();
        list.add(new Toto());
        JavaRDD<Toto> cursor = context.parallelize(list, list.size());

        JavaPairRDD<Toto, Integer> writable = cursor.mapToPair(WRITABLE_CONVERTOR);
        writable.saveAsHadoopFile(args[0], Toto.class, Integer.class, SequenceFileOutputFormat.class);

        context.close();
    }

}

但我有个错误：
java.io.ioexception:找不到键类的序列化程序：“com.test.serializetest.toto”。如果使用自定义序列化，请确保配置“io.serializations”配置正确。在org.apache.hadoop.io.sequencefile$writer.init（sequencefile。java:1179)在org.apache.hadoop.io.sequencefile$writer。java:1094)在org.apache.hadoop.io.sequencefile.createwriter（sequencefile。java:273)在org.apache.hadoop.io.sequencefile.createwriter（sequencefile。java:530)在org.apache.hadoop.mapred.sequencefileoutputformat.getrecordwriter（sequencefileoutputformat）。java:63)在org.apache.spark.sparkhadoopwriter.open（sparkhadoopwriter。scala:90)在org.apache.spark.rdd.pairddfunctions$$anonfun$13.apply（pairddfunctions。scala:1068)在org.apache.spark.rdd.pairddfunctions$$anonfun$13.apply（pairddfunctions。scala:1059)在org.apache.spark.scheduler.resulttask.runtask（resulttask。scala:61)在org.apache.spark.scheduler.task.run（task。scala:64)在org.apache.spark.executor.executor$taskrunner.run（executor。scala:203)位于java.util.concurrent.threadpoolexecutor.runworker（threadpoolexecutor。java:1142)在java.util.concurrent.threadpoolexecutor$worker.run（threadpoolexecutor。java:617)在java.lang.thread.run（线程。java:745)15/09/21 17:49:14警告tasksetmanager:阶段0.0（tid 0，localhost）中的任务0.0丢失：java.io.ioexception:找不到密钥类的序列化程序：“com.test.serializetest.toto”。如果使用自定义序列化，请确保配置“io.serializations”配置正确。在org.apache.hadoop.io.sequencefile$writer.init（sequencefile。java:1179)在org.apache.hadoop.io.sequencefile$writer。java:1094)在org.apache.hadoop.io.sequencefile.createwriter（sequencefile。java:273)在org.apache.hadoop.io.sequencefile.createwriter（sequencefile。java:530)在org.apache.hadoop.mapred.sequencefileoutputformat.getrecordwriter（sequencefileoutputformat）。java:63)在org.apache.spark.sparkhadoopwriter.open（sparkhadoopwriter。scala:90)在org.apache.spark.rdd.pairddfunctions$$anonfun$13.apply（pairddfunctions。scala:1068)在org.apache.spark.rdd.pairddfunctions$$anonfun$13.apply（pairddfunctions。scala:1059)在org.apache.spark.scheduler.resulttask.runtask（resulttask。scala:61)在org.apache.spark.scheduler.task.run（task。scala:64)在org.apache.spark.executor.executor$taskrunner.run（executor。scala:203)位于java.util.concurrent.threadpoolexecutor.runworker（threadpoolexecutor。java:1142)在java.util.concurrent.threadpoolexecutor$worker.run（threadpoolexecutor。java:617)在java.lang.thread.run（线程。java:745)
谢谢。