Supported Types

The IC4J Candid Library allows Java developers to serialize and deserialize Java native types to IC Candid IDL types.

"Candid is an interface description language. Its primary purpose is to describe the public interface of a service, usually in the form of a program deployed as a canister smart contract that runs on the Internet Computer. One of the key benefits of Candid is that it is language-agnostic, and allows inter-operation between services and front-ends written in different programming languages, including Motoko, Rust, and JavaScript."

Internet Computer | DocumentationDFINITYDev

What is Candid?

Internet Computer | DocumentationDFINITYDev

Candid Types

This table shows implicit mapping between Candid types and default Java type assignment.

Candid	Java
bool	Boolean
int	BigInteger
int8	Byte
int16	Short
int32	Integer
int64	Long
nat	BigInteger
nat8	Byte
nat16	Short
nat32	Integer
nat64	Long
float32	Float
float64	Double
text	String
opt	Optional
principal	Principal
vec	array, List
record	Map, Class
variant	Map, Enum
func	Func
service	Service
null	Null