Awesome

dfinity-agent

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 <a href="https://docs.ic4j.com"> here</a>

The code is implementation of the Internet Computer Interface protocol

and it's using Dfinity Rust agent as an inspiration, using similar package structures and naming conventions.

License

IC4J Candid is available under Apache License 2.0.

Documentation

Supported type mapping between Java and Candid

POJO Java class with Candid annotations

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); 
				

JSON (Jackson) serialization and deserialization

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);

XML (DOM) serialization and deserialization

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);

JDBC (ResultSet) serialization

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();

Downloads / Accessing Binaries

To add Java IC4J Candid library to your Java project use Maven or Gradle import from Maven Central.

<dependency>
  <groupId>org.ic4j</groupId>
  <artifactId>ic4j-candid</artifactId>
  <version>0.7.4</version>
</dependency>

implementation 'org.ic4j:ic4j-candid:0.7.4'

Dependencies

This this is using these open source libraries

Jackson JSON Serializer and Deserializer

To manage Jackson objects.

Java CC

To parse IC IDL Candid files

Build

You need JDK 8+ to build IC4J Candid.