Java Candid for The Internet Computer (IC4J) is a collection of open-source native Java libraries designed to handle Candid types on the Internet Computer. Full documentation here
https://dfinity.org/The code is implementation of the Internet Computer Interface protocol
https://sdk.dfinity.org/docs/interface-spec/index.htmland it's using Dfinity Rust agent as an inspiration, using similar package structures and naming conventions.
https://github.com/dfinity/agent-rsIC4J Candid is available under Apache License 2.0.
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, Double |
float64 | Double |
text | String |
opt | Optional |
principal | Principal |
vec | array, List |
record | Map, Class |
variant | Map, Enum |
func | Func |
service | Service |
null | Null |
import java.math.BigInteger;
import org.ic4j.candid.annotations.Field;
import org.ic4j.candid.annotations.Name;
import org.ic4j.candid.types.Type;
public class Pojo {
@Field(Type.BOOL)
@Name("bar")
public Boolean bar;
@Field(Type.INT)
@Name("foo")
public BigInteger foo;
}
Pojo pojoValue = new Pojo();
pojoValue.bar = new Boolean(false);
pojoValue.foo = BigInteger.valueOf(43);
Use JacksonSerializer to serialize Jackson JsonNode or Jackson compatible Pojo class to Candid
JsonNode jsonValue;
IDLType idlType;
IDLValue idlValue = IDLValue.create(jsonValue, JacksonSerializer.create(idlType));
List<IDLValue> args = new ArrayList<IDLValue>();
args.add(idlValue);
IDLArgs idlArgs = IDLArgs.create(args);
byte[] buf = idlArgs.toBytes();
Use JacksonDeserializer to deserialize Candid to Jackson JsonNode or Jackson compatible Pojo class
JsonNode jsonResult = IDLArgs.fromBytes(buf).getArgs().get(0)
.getValue(JacksonDeserializer.create(idlValue.getIDLType()), JsonNode.class);
Use DOMSerializer to serialize DOM Node to Candid
Node domValue;
IDLValue idlValue = IDLValue.create(domValue,DOMSerializer.create());
List<IDLValue> args = new ArrayList<IDLValue>();
args.add(idlValue);
IDLArgs idlArgs = IDLArgs.create(args);
byte[] buf = idlArgs.toBytes();
Use DOMDeserializer to deserialize Candid to DOM Node
DOMDeserializer domDeserializer = DOMDeserializer.create(idlValue.getIDLType()).rootElement("http://scaleton.com/dfinity/candid","data");
Node domResult = IDLArgs.fromBytes(buf).getArgs().get(0).getValue(domDeserializer, Node.class);
Use JDBCSerializer to serialize JDBC ResultSet to Candid
ResultSet result = statement.executeQuery(sql);
IDLValue idlValue = IDLValue.create(result, JDBCSerializer.create());
List<IDLValue> args = new ArrayList<IDLValue>();
args.add(idlValue);
IDLArgs idlArgs = IDLArgs.create(args);
byte[] buf = idlArgs.toBytes();
To add Java IC4J Candid library to your Java project use Maven or Gradle import from Maven Central.
https://search.maven.org/artifact/ic4j/ic4j-candid/0.7.1/jar<dependency>
<groupId>org.ic4j</groupId>
<artifactId>ic4j-candid</artifactId>
<version>0.7.1</version>
</dependency>
implementation 'org.ic4j:ic4j-candid:0.7.1'
This this is using these open source libraries
To manage Jackson objects.
To parse IC IDL Candid files
You need JDK 8+ to build IC4J Candid.