IHMC ROS 2 Library

ROS2 messaging for Java. Implements a ROS 2 compatible layer with a Java JNI layer on top of Fast-DDS.

Features

• Easy-to-use API for publishing and subscribing to ROS 2 topics
• Allocation free modules for realtime support
• Carries documentation from .msg files into Javadoc
• Gradle task for .msg -> .java generation
• Provided Java library for ROS common_interfaces, rcl_interfaces, and geometry2
• ROS 2 .msg to ROS 1 .msg generation
• Official ROS 2 compatibility when used with Fast-DDS middleware

Usage

This library provides a minimal implementation of a ROS 2 node in Java. Two versions are available:

• ROS2Node: Publishes in the same thread and uses direct callbacks for incoming messages.
• RealtimeROS2Node: Stores outgoing and incoming messages in a queue and uses non-blocking calls to publish messages and allows polling for new messages.

Create ROS2Node and RealtimeROS2Node with ROS2NodeBuilder:

ROS2Node ros2Node = new ROS2NodeBuilder().build("test_node");
RealtimeROS2Node realtimeROS2Node = new ROS2NodeBuilder().buildRealtime("realtime_test_node");

Gradle

dependencies {
  implementation("us.ihmc:ros2-library:1.0.0")
}

Examples

See ROS2TalkerExample.java and ROS2PublishSubscribeExample.java.

Environment Options

Environment Variable	Description
ROS_DOMAIN_ID	Set the ROS 2 domain ID to use (integer, 0-101)
ROS_DEFAULT_QOS	QoS for topics that don't specify it (RELIABLE or BEST_EFFORT)

Note

The intermediate .idl files generated by this library are not valid to be used outside IHMC Pub/Sub.