std_srvs/Empty型のサービス・クライアント作成 (Python/C++)

std_service/Empty型のサービス・クライアントのサンプルプログラムを記載します。

• サーバー(Python)

empty_service_server.py

# !/usr/bin/env python

from std_srvs.srv import Empty
from std_srvs.srv import EmptyResponse
import rospy

def handle(req):
    print("service call")
    return EmptyResponse()

def empty_server():
    rospy.init_node('empty_service_server')
    s = rospy.Service('empty_service', Empty, handle)
    rospy.spin()

if __name__ == "__main__":
    empty_server()

• クライアント(Python)

empty_service_client.py

# !/usr/bin/env python

from std_srvs.srv import Empty
import rospy

rospy.init_node('empty_service_client')

service_name = 'empty_service'
rospy.wait_for_service(service_name)
empty_service = rospy.ServiceProxy(service_name, Empty)

r = rospy.Rate(20)

while not rospy.is_shutdown() :
  print("call")
  empty_service()
  r.sleep()

• サーバー(C++)

empty_service_server.cpp

# include "ros/ros.h"
# include "std_srvs/Empty.h"
# include "std_srvs/EmptyResponse.h"

bool handle(std_srvs::Empty::Request &req, std_srvs::Empty::Response &res)
{
  std::cout << "service call" << std::endl;
  return true;
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "empty_service_server");
  ros::NodeHandle n;

  ros::ServiceServer service = n.advertiseService("empty_service", handle);

  ros::spin();
}

• クライアント(C++)

empty_service_client.cpp

# include "ros/ros.h"
# include "std_srvs/Empty.h"

int main(int argc, char **argv)
{
  ros::init(argc, argv, "empty_service_client");

  ros::NodeHandle n;

  ros::ServiceClient client = n.serviceClient<std_srvs::Empty>("empty_service");

  ros::Rate r(10);

  std_srvs::Empty srv;
  
  while (ros::ok())
  {
    client.call(srv);   
    r.sleep();
  }

  return 0;
}

• 上記c++プログラムの2つのcmakeファイル

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.2)
project(empty_service)

find_package(catkin REQUIRED roscpp std_srvs)

catkin_package(
)

include_directories(
  ${catkin_INCLUDE_DIRS}
)

add_executable(empty_service_server src/empty_service_server.cpp)
target_link_libraries(empty_service_server
  ${catkin_LIBRARIES}
)

add_executable(empty_service_client src/empty_service_client.cpp)
target_link_libraries(empty_service_client
  ${catkin_LIBRARIES}
)