PostgreSQL Types

Supported Java types and their destination types on PostgreSQL

All types also support their array versions, but they are returned as IndexedSeq of the type and not pure Array types.

PostgreSQL type	Java type
boolean	Boolean
smallint	Short
integer (or serial)	Int
bigint (or bigserial)	Long
numeric	BigDecimal
real	Float
double	Double
text	String
varchar	String
bpchar	String
timestamp	LocalDateTime
timestamp_with_timezone	DateTime
date	LocalDate
time	LocalTime
bytea	Array[Byte] (PostgreSQL 9.0 and above only)

All other types are returned as String.

Now from Scala/Java types to PostgreSQL types (when using prepared statements):

Java type	PostgreSQL type
Boolean	boolean
Short	smallint
Int	integer
Long	bigint
Float	float
Double	double
BigInteger	numeric
BigDecimal	numeric
String	varchar
Array[Byte]	bytea (PostgreSQL 9.0 and above only)
java.nio.ByteBuffer	bytea (PostgreSQL 9.0 and above only)
io.netty.buffer.ByteBuf	bytea (PostgreSQL 9.0 and above only)
java.util.Date	timestamp_with_timezone
java.sql.Timestamp	timestamp_with_timezone
java.sql.Date	date
java.sql.Time	time
LocalDate	date
LocalDateTime	timestamp
DateTime	timestamp_with_timezone
LocalTime	time

Array types are encoded with the kind of object they hold and not the array type itself. Java Collection and Scala Traversable objects are also assumed to be arrays of the types they hold and will be sent to PostgreSQL like that.
null values are supported, In prepared statement pass null.
Spatial / Geometry data types (postgis<->jts) are supported via module jasync-postgis-jts. In order to use geometry types import the module and init with the following code:

JasyncPostgisRegister.init(connection)