How to insert java.util.Date values into Cassandra

问题:

I have cassandra table with a date type column as follows:

create table people
(
   id int primary key, 
   name text, 
   email text, 
   dob date
);

I am using SpringBoot 1.5.2 + Spring Data Cassandra Starter.

@Table("people")
public class Person {
    @PrimaryKey
    Integer id;
    private String name;
    private String email;
    private java.util.Date dob;
    //setters and getters
}

public interface PersonRepository extends CrudRepository<Person, Integer>{

}

I am inserting new Person as follows:

personRepository.save(new Person(1, "Siva","[e-mail]", new java.util.Date()));

It is throwing the following error:

Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: Expected 4 byte long for date (8)
    at com.datastax.driver.core.Responses$Error.asException(Responses.java:136) ~[cassandra-driver-core-3.1.4.jar:na]
    at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:179) ~[cassandra-driver-core-3.1.4.jar:na]
    at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:177) ~[cassandra-driver-core-3.1.4.jar:na]
    at com.datastax.driver.core.RequestHandler.access$2500(RequestHandler.java:46) ~[cassandra-driver-core-3.1.4.jar:na]

But if I make dob column type to timestamp then it is working fine. Is it possible to have date type column and use java.util.Date type properties?

P.s: Even if I use java.sql.Date I am getting the same error.

回答1:

Use com.datastax.driver.core.LocalDate

You can use any of these method to get LocalDate from java.util.Date

• LocalDate.fromYearMonthDay(2017, 03, 28)
• LocalDate.fromMillisSinceEpoch(new Date().getTime())

Or you could create your own codec that will allow you to insert java.util.Date into Cassandra date type.

You can start like the below one :

public class DateCodec extends TypeCodec<Date> {

    private final TypeCodec<LocalDate> innerCodec;

    public DateCodec(TypeCodec<LocalDate> codec, Class<Date> javaClass) {
        super(codec.getCqlType(), javaClass);
        innerCodec = codec;
    }

    @Override
    public ByteBuffer serialize(Date value, ProtocolVersion protocolVersion) throws InvalidTypeException {
        return innerCodec.serialize(LocalDate.fromMillisSinceEpoch(value.getTime()), protocolVersion);
    }

    @Override
    public Date deserialize(ByteBuffer bytes, ProtocolVersion protocolVersion) throws InvalidTypeException {
        return new Date(innerCodec.deserialize(bytes, protocolVersion).getMillisSinceEpoch());
    }

    @Override
    public Date parse(String value) throws InvalidTypeException {
        return new Date(innerCodec.parse(value).getMillisSinceEpoch());
    }

    @Override
    public String format(Date value) throws InvalidTypeException {
        return value.toString();
    }

}

When creating connectin you have to register :

CodecRegistry codecRegistry = new CodecRegistry();
codecRegistry.register(new DateCodec(TypeCodec.date(), Date.class));
Cluster.builder().withCodecRegistry(codecRegistry).build();

For more : http://docs.datastax.com/en/developer/java-driver/3.1/manual/custom_codecs/