JRE
Android
This is a set of projects (bindings, code generator, examples and more) that enables developers to write ROS2 applications for the JVM and Android.
Besides this repository itself, there's also:
- https://github.com/esteve/ament_java, which adds support for Gradle to Ament
- https://github.com/esteve/ament_gradle_plugin, a Gradle plugin that makes it easier to use ROS2 in Java and Android project, and which can be found published at the Gradle Central at https://plugins.gradle.org/plugin/org.ros2.tools.gradle
- https://github.com/esteve/ros2_java_examples, examples for the Java Runtime Environment
- https://github.com/esteve/ros2_android_examples, examples for Android
No, any language that targets the JVM can be used to write ROS2 applications.
Yep! Make sure to use this fork as your DDS vendor.
The current set of features include:
- Generation of all builtin and complex ROS types, including arrays, strings, nested types, constants, etc.
- Support for publishers and subscriptions
- Tunable Quality of Service (e.g. lossy networks, reliable delivery, etc.)
- Clients and services
- Support for Android
First of all, download the ament repositories in a separate workspace:
mkdir -p ~/ament_ws/src
cd ~/ament_ws
wget https://raw.githubusercontent.com/esteve/ament_java/master/ament_java.repos
vcs import ~/ament_ws/src < ament_java.repos
src/ament/ament_tools/scripts/ament.py build --symlink-install --isolated
You may wonder why this is needed if the ROS2 instructions already fetch Ament on the same workspace as ROS2.
The reason is that this includes an additional build type for Gradle projects, and you'll need Ament to pick it up so it can build the examples, so this has to happen in a separate step.
The following sections deal with building the ros2_java codebase for the desktop Java runtime and for Android.
mkdir -p ~/ros2_java_ws/src
cd ~/ros2_java_ws
wget https://raw.githubusercontent.com/esteve/ros2_java/master/ros2_java_desktop.repos
vcs import ~/ros2_java_ws/src < ros2_java_desktop.repos
cd ~/ros2_java_ws/src/ros2/rosidl_typesupport
patch -p1 < ../../ros2_java/ros2_java/rosidl_typesupport_ros2_java.patch
cd ~/ros2_java_ws
. ~/ament_ws/install_isolated/local_setup.sh
ament build --symlink-install --isolated
Now you can just run a couple of examples.
Talker:
. ~/ament_ws/install_isolated/local_setup.sh
. ~/ros2_java_ws/install_isolated/local_setup.sh
cd ~/ros2_java_ws
java -cp install_isolated/rcljava_common/share/rcljava_common/java/slf4j-jdk14-1.7.21.jar:install_isolated/rcljava_common/share/rcljava_common/java/slf4j-api-1.7.21.jar:install_isolated/std_msgs/share/std_msgs/java/std_msgs.jar:install_isolated/rcljava/share/rcljava/java/rcljava.jar:install_isolated/rcljava_examples/share/rcljava_examples/java/rcljava_examples.jar:install_isolated/example_interfaces/share/example_interfaces/java/example_interfaces.jar:install_isolated/rcljava_common/share/rcljava_common/java/rcljava_common.jar org.ros2.rcljava.examples.Talker
Listener:
. ~/ament_ws/install_isolated/local_setup.sh
. ~/ros2_java_ws/install_isolated/local_setup.sh
cd ~/ros2_java_ws
java -cp install_isolated/rcljava_common/share/rcljava_common/java/slf4j-jdk14-1.7.21.jar:install_isolated/rcljava_common/share/rcljava_common/java/slf4j-api-1.7.21.jar:install_isolated/std_msgs/share/std_msgs/java/std_msgs.jar:install_isolated/rcljava/share/rcljava/java/rcljava.jar:install_isolated/rcljava_examples/share/rcljava_examples/java/rcljava_examples.jar:install_isolated/example_interfaces/share/example_interfaces/java/example_interfaces.jar:install_isolated/rcljava_common/share/rcljava_common/java/rcljava_common.jar org.ros2.rcljava.examples.Listener
Client:
. ~/ament_ws/install_isolated/local_setup.sh
. ~/ros2_java_ws/install_isolated/local_setup.sh
cd ~/ros2_java_ws
java -cp install_isolated/rcljava_common/share/rcljava_common/java/slf4j-jdk14-1.7.21.jar:install_isolated/rcljava_common/share/rcljava_common/java/slf4j-api-1.7.21.jar:install_isolated/std_msgs/share/std_msgs/java/std_msgs.jar:install_isolated/rcljava/share/rcljava/java/rcljava.jar:install_isolated/rcljava_examples/share/rcljava_examples/java/rcljava_examples.jar:install_isolated/example_interfaces/share/example_interfaces/java/example_interfaces.jar:install_isolated/rcljava_common/share/rcljava_common/java/rcljava_common.jar org.ros2.rcljava.examples.AddTwoIntsClient
Service:
. ~/ament_ws/install_isolated/local_setup.sh
. ~/ros2_java_ws/install_isolated/local_setup.sh
cd ~/ros2_java_ws
java -cp install_isolated/rcljava_common/share/rcljava_common/java/slf4j-jdk14-1.7.21.jar:install_isolated/rcljava_common/share/rcljava_common/java/slf4j-api-1.7.21.jar:install_isolated/std_msgs/share/std_msgs/java/std_msgs.jar:install_isolated/rcljava/share/rcljava/java/rcljava.jar:install_isolated/rcljava_examples/share/rcljava_examples/java/rcljava_examples.jar:install_isolated/example_interfaces/share/example_interfaces/java/example_interfaces.jar:install_isolated/rcljava_common/share/rcljava_common/java/rcljava_common.jar org.ros2.rcljava.examples.AddTwoIntsService
You can also combine any scenario where the talker/listener or client/service are written in Java, Python and C++ and they should talk to each other.
The Android setup is slightly more complex, you'll need the SDK and NDK installed, and an Android device where you can run the examples.
Make sure to download at least the SDK for Android Lollipop (or greater), the examples require the API level 21 at least.
You may download the Android NDK from the official website, let's assume you unpack it to ~/android_ndk
mkdir -p ~/ros2_android_ws/src
cd ~/ros2_android_ws
wget https://raw.githubusercontent.com/esteve/ros2_java/master/ros2_java_android.repos
vcs import ~/ros2_android_ws/src < ros2_java_android.repos
cd ~/ros2_android_ws/src/ros2/rosidl
touch python_cmake_module/AMENT_IGNORE
touch rosidl_generator_py/AMENT_IGNORE
cd ~/ros2_android_ws/src/ros2/rosidl_typesupport
patch -p1 < ../../ros2_java/ros2_java/rosidl_typesupport_ros2_android.patch
cd ~/ros2_android_ws/src/eProsima/Fast-RTPS
git submodule init
git submodule update
cd ~/ros2_android_ws
. ~/ament_ws/install_isolated/local_setup.sh
ament build --isolated --cmake-args \
-DPYTHON_EXECUTABLE=/usr/bin/python3 -DCMAKE_TOOLCHAIN_FILE=$HOME/android_ndk/android-ndk-r13b/build/cmake/android.toolchain.cmake \
-DANDROID_FUNCTION_LEVEL_LINKING=OFF -DANDROID_NATIVE_API_LEVEL=android-21 \
-DANDROID_TOOLCHAIN_NAME=arm-linux-androideabi-clang -DANDROID_STL=gnustl_shared \
-DANDROID_ABI=armeabi-v7a -DANDROID_NDK=$HOME/android_ndk/android-ndk-r13b -DTHIRDPARTY=ON -DCOMPILE_EXAMPLES=OFF -DCMAKE_FIND_ROOT_PATH="$HOME/ament_ws/install_isolated;$HOME/ros2_android_ws/install_isolated" \
-DANDROID_CPP_FEATURES="exceptions rtti" -- \
--ament-cmake-args \
-DPYTHON_EXECUTABLE=/usr/bin/python3 -DCMAKE_TOOLCHAIN_FILE=$HOME/android_ndk/android-ndk-r13b/build/cmake/android.toolchain.cmake \
-DANDROID_FUNCTION_LEVEL_LINKING=OFF -DANDROID_NATIVE_API_LEVEL=android-21 \
-DANDROID_TOOLCHAIN_NAME=arm-linux-androideabi-clang -DANDROID_STL=gnustl_shared \
-DANDROID_ABI=armeabi-v7a -DANDROID_NDK=$HOME/android_ndk/android-ndk-r13b -DTHIRDPARTY=ON -DCOMPILE_EXAMPLES=OFF -DCMAKE_FIND_ROOT_PATH="$HOME/ament_ws/install_isolated;$HOME/ros2_android_ws/install_isolated" \
-DANDROID_CPP_FEATURES="exceptions rtti" -- \
--ament-gradle-args \
-Pament.android_stl=gnustl_shared -Pament.android_abi=armeabi-v7a -Pament.android_ndk=$HOME/android_ndk/android-ndk-r13b --
The talker and listener example Android apps can be installed via adb, plug your Android device to your computer with a USB cable and type the following:
Talker:
adb install ~/ros2_android_ws/install_isolated/ros2_talker_android/ros2_talker_android-debug.apk
Listener:
adb install ~/ros2_android_ws/install_isolated/ros2_listener_android/ros2_listener_android-debug.apk
You can try out running the talker on the desktop and the listener on your Android device or viceversa.
Enjoy!
Thanks all those who have contributed:
Mickael Gaillard (https://github.com/Theosakamg)
There's a bunch of features missing, including efficient intraprocess communication and DDS domain separation.
Large messages would benefit from Java's NIO.
And of course, this wouldn't be a proper opensource project if it didn't lack tests and documentation, so there's that too.