diff --git a/rcljava/src/main/java/org/ros2/rcljava/client/Client.java b/rcljava/src/main/java/org/ros2/rcljava/client/Client.java
index 774ecec6..811aa2c5 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/client/Client.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/client/Client.java
@@ -26,9 +26,7 @@
 import org.ros2.rcljava.service.RMWRequestId;
 
 public interface Client<T extends ServiceDefinition> extends Disposable {
-  <U extends MessageDefinition> Class<U> getRequestType();
-
-  <U extends MessageDefinition> Class<U> getResponseType();
+  ServiceDefinition getServiceDefinition();
 
   <U extends MessageDefinition> void handleResponse(RMWRequestId header, U response);
 
diff --git a/rcljava/src/main/java/org/ros2/rcljava/client/ClientImpl.java b/rcljava/src/main/java/org/ros2/rcljava/client/ClientImpl.java
index 3c3187e3..442aa8ec 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/client/ClientImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/client/ClientImpl.java
@@ -55,20 +55,25 @@ public class ClientImpl<T extends ServiceDefinition> implements Client<T> {
   private final String serviceName;
   private Map<Long, Map.Entry<Consumer, RCLFuture>> pendingRequests;
 
-  private final Class<MessageDefinition> requestType;
-  private final Class<MessageDefinition> responseType;
-
-  public ClientImpl(final WeakReference<Node> nodeReference, final long handle,
-      final String serviceName, final Class<MessageDefinition> requestType,
-      final Class<MessageDefinition> responseType) {
+  private final ServiceDefinition serviceDefinition;
+
+  public ClientImpl(
+    final ServiceDefinition serviceDefinition,
+    final WeakReference<Node> nodeReference,
+    final long handle,
+    final String serviceName)
+  {
     this.nodeReference = nodeReference;
     this.handle = handle;
     this.serviceName = serviceName;
-    this.requestType = requestType;
-    this.responseType = responseType;
+    this.serviceDefinition = serviceDefinition;
     this.pendingRequests = new HashMap<Long, Map.Entry<Consumer, RCLFuture>>();
   }
 
+  public ServiceDefinition getServiceDefinition() {
+    return this.serviceDefinition;
+  }
+
   public final <U extends MessageDefinition, V extends MessageDefinition> Future<V>
   asyncSendRequest(final U request) {
     return asyncSendRequest(request, new Consumer<Future<V>>() {
@@ -112,14 +117,6 @@ private static native long nativeSendClientRequest(
       long handle, long requestFromJavaConverterHandle, long requestDestructorHandle,
       MessageDefinition requestMessage);
 
-  public final Class<MessageDefinition> getRequestType() {
-    return this.requestType;
-  }
-
-  public final Class<MessageDefinition> getResponseType() {
-    return this.responseType;
-  }
-
   /**
    * Destroy a ROS2 client (rcl_client_t).
    *
diff --git a/rcljava/src/main/java/org/ros2/rcljava/executors/BaseExecutor.java b/rcljava/src/main/java/org/ros2/rcljava/executors/BaseExecutor.java
index bd86e63a..5c43b6c4 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/executors/BaseExecutor.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/executors/BaseExecutor.java
@@ -118,18 +118,9 @@ protected void executeAnyExecutable(AnyExecutable anyExecutable) {
     }
 
     if (anyExecutable.service != null) {
-      Class<? extends MessageDefinition> requestType = anyExecutable.service.getRequestType();
-      Class<? extends MessageDefinition> responseType = anyExecutable.service.getResponseType();
-
-      MessageDefinition requestMessage = null;
-      MessageDefinition responseMessage = null;
-
-      try {
-        requestMessage = requestType.getDeclaredConstructor().newInstance();
-        responseMessage = responseType.getDeclaredConstructor().newInstance();
-      } catch (ReflectiveOperationException e) {
-        throw new IllegalStateException("Failed to instantiate service request/response");
-      }
+      ServiceDefinition serviceDefinition = anyExecutable.service.getServiceDefinition();
+      MessageDefinition requestMessage = serviceDefinition.newRequestInstance();
+      MessageDefinition responseMessage = serviceDefinition.newResponseInstance();
 
       if (requestMessage != null && responseMessage != null) {
         long requestFromJavaConverterHandle = requestMessage.getFromJavaConverterInstance();
@@ -140,28 +131,21 @@ protected void executeAnyExecutable(AnyExecutable anyExecutable) {
         long responseDestructorHandle = responseMessage.getDestructorInstance();
 
         RMWRequestId rmwRequestId =
-            nativeTakeRequest(anyExecutable.service.getHandle(), requestFromJavaConverterHandle,
-                requestToJavaConverterHandle, requestDestructorHandle, requestMessage);
+          nativeTakeRequest(anyExecutable.service.getHandle(), requestFromJavaConverterHandle,
+            requestToJavaConverterHandle, requestDestructorHandle, requestMessage);
         if (rmwRequestId != null) {
           anyExecutable.service.executeCallback(rmwRequestId, requestMessage, responseMessage);
-          nativeSendServiceResponse(anyExecutable.service.getHandle(), rmwRequestId,
-              responseFromJavaConverterHandle, responseDestructorHandle, responseMessage);
+          nativeSendServiceResponse(
+            anyExecutable.service.getHandle(), rmwRequestId,
+            responseFromJavaConverterHandle, responseDestructorHandle, responseMessage);
         }
       }
       serviceHandles.remove(anyExecutable.service.getHandle());
     }
 
     if (anyExecutable.client != null) {
-      Class<? extends MessageDefinition> requestType = anyExecutable.client.getRequestType();
-      Class<? extends MessageDefinition> responseType = anyExecutable.client.getResponseType();
-
-      MessageDefinition responseMessage = null;
-
-      try {
-        responseMessage = responseType.getDeclaredConstructor().newInstance();
-      } catch (ReflectiveOperationException ie) {
-        throw new IllegalStateException("Failed to instantiate service response");
-      }
+      ServiceDefinition serviceDefinition = anyExecutable.client.getServiceDefinition();
+      MessageDefinition responseMessage = serviceDefinition.newResponseInstance();
 
       if (responseMessage != null) {
         long responseFromJavaConverterHandle = responseMessage.getFromJavaConverterInstance();
diff --git a/rcljava/src/main/java/org/ros2/rcljava/node/Node.java b/rcljava/src/main/java/org/ros2/rcljava/node/Node.java
index 63dc6b24..43d470d6 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/node/Node.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/node/Node.java
@@ -39,6 +39,8 @@
 import org.ros2.rcljava.parameters.ParameterCallback;
 import org.ros2.rcljava.parameters.ParameterType;
 import org.ros2.rcljava.parameters.ParameterVariant;
+import org.ros2.rcljava.parameters.client.AsyncParametersClient;
+import org.ros2.rcljava.parameters.client.SyncParametersClient;
 import org.ros2.rcljava.publisher.Publisher;
 import org.ros2.rcljava.qos.QoSProfile;
 import org.ros2.rcljava.service.RMWRequestId;
@@ -126,23 +128,24 @@ <T extends MessageDefinition> Publisher<T> createPublisher(
   <T extends MessageDefinition> Publisher<T> createPublisher(
       final Class<T> messageType, final String topic);
 
-  <T extends ServiceDefinition> Service<T> createService(final Class<T> serviceType,
+  <T extends ServiceDefinition> Service<T> createService(
+      final Class<T> serviceType,
       final String serviceName,
       final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
           callback,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException;
+      final QoSProfile qosProfile);
 
-  <T extends ServiceDefinition> Service<T> createService(final Class<T> serviceType,
+  <T extends ServiceDefinition> Service<T> createService(
+      final Class<T> serviceType,
       final String serviceName,
       final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
-          callback) throws NoSuchFieldException, IllegalAccessException;
+          callback);
 
   <T extends ServiceDefinition> Client<T> createClient(
-      final Class<T> serviceType, final String serviceName, final QoSProfile qosProfile)
-      throws NoSuchFieldException, IllegalAccessException;
+      final Class<T> serviceType, final String serviceName, final QoSProfile qosProfile);
 
-  <T extends ServiceDefinition> Client<T> createClient(final Class<T> serviceType,
-      final String serviceName) throws NoSuchFieldException, IllegalAccessException;
+  <T extends ServiceDefinition> Client<T> createClient(
+      final Class<T> serviceType, final String serviceName);
 
   /**
    * Create an ActionServer&lt;T&gt;.
@@ -263,6 +266,16 @@ <T extends ActionDefinition> ActionServer<T> createActionServer(final Class<T> a
    */
   String getNamespace();
 
+  /**
+   * Create an asynchronous parameter client.
+   */
+  AsyncParametersClient createAsyncParametersClient(String nodeName);
+
+  /**
+   * Create an synchronous parameter client.
+   */
+  SyncParametersClient createSyncParametersClient(String nodeName);
+
   /**
    * Declare and initialize a parameter, return the effective value.
    *
diff --git a/rcljava/src/main/java/org/ros2/rcljava/node/NodeImpl.java b/rcljava/src/main/java/org/ros2/rcljava/node/NodeImpl.java
index 3bfb0e4b..3ca6cfb6 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/node/NodeImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/node/NodeImpl.java
@@ -44,6 +44,10 @@
 import org.ros2.rcljava.parameters.ParameterNotDeclaredException;
 import org.ros2.rcljava.parameters.ParameterType;
 import org.ros2.rcljava.parameters.ParameterVariant;
+import org.ros2.rcljava.parameters.client.AsyncParametersClient;
+import org.ros2.rcljava.parameters.client.AsyncParametersClientImpl;
+import org.ros2.rcljava.parameters.client.SyncParametersClient;
+import org.ros2.rcljava.parameters.client.SyncParametersClientImpl;
 import org.ros2.rcljava.parameters.service.ParameterService;
 import org.ros2.rcljava.parameters.service.ParameterServiceImpl;
 import org.ros2.rcljava.publisher.Publisher;
@@ -191,18 +195,8 @@ public NodeImpl(final long handle, final NodeOptions nodeOptions) {
     this.wall_clock = new Clock(ClockType.STEADY_TIME);
     this.timeSource = new TimeSource(this);
     this.timeSource.attachClock(this.clock);
-    try {
-      this.parameterService = nodeOptions.getStartParameterServices() ?
-        new ParameterServiceImpl(this) : null;
-    // TODO(ivanpauno): Modify createService, createClient so they don't declare
-    // NoSuchFieldException and IllegalAccessException checked exceptions.
-    // That only happens if the user passed the wrong Class object, and the exception should
-    // be rethrown as an unchecked IllegalArgumentException.
-    } catch (NoSuchFieldException ex) {
-      throw new IllegalArgumentException(ex.getMessage());
-    } catch (IllegalAccessException ex) {
-      throw new IllegalArgumentException(ex.getMessage());
-    }
+    this.parameterService = nodeOptions.getStartParameterServices() ?
+      new ParameterServiceImpl(this) : null;
   }
 
   /**
@@ -340,30 +334,39 @@ private static native <T extends ServiceDefinition> long nativeCreateServiceHand
       long handle, Class<T> cls, String serviceName, long qosProfileHandle);
 
   public final <T extends ServiceDefinition> Service<T> createService(final Class<T> serviceType,
-      final String serviceName,
-      final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
-          callback,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException {
-    Class<MessageDefinition> requestType = (Class) serviceType.getField("RequestType").get(null);
-
-    Class<MessageDefinition> responseType = (Class) serviceType.getField("ResponseType").get(null);
-
+    final String serviceName,
+    final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
+      callback,
+    final QoSProfile qosProfile)
+  {
+    T serviceDefinition;
+    try {
+      serviceDefinition = serviceType.getDeclaredConstructor().newInstance();
+    } catch (ReflectiveOperationException e) {
+      throw new IllegalStateException("Failed to instantiate service definition");
+    }
     long qosProfileHandle = RCLJava.convertQoSProfileToHandle(qosProfile);
     long serviceHandle =
         nativeCreateServiceHandle(this.handle, serviceType, serviceName, qosProfileHandle);
     RCLJava.disposeQoSProfile(qosProfileHandle);
 
-    Service<T> service = new ServiceImpl<T>(new WeakReference<Node>(this), serviceHandle,
-        serviceName, callback, requestType, responseType);
+    Service<T> service = new ServiceImpl<T>(
+      serviceDefinition,
+      new WeakReference<Node>(this),
+      serviceHandle,
+      serviceName,
+      callback);
     this.services.add(service);
 
     return service;
   }
 
-  public <T extends ServiceDefinition> Service<T> createService(final Class<T> serviceType,
-      final String serviceName,
-      final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
-          callback) throws NoSuchFieldException, IllegalAccessException {
+  public <T extends ServiceDefinition> Service<T> createService(
+    final Class<T> serviceType,
+    final String serviceName,
+    final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
+      callback)
+  {
     return this.<T>createService(serviceType, serviceName, callback, QoSProfile.SERVICES_DEFAULT);
   }
 
@@ -375,26 +378,29 @@ public final Collection<Service> getServices() {
   }
 
   public final <T extends ServiceDefinition> Client<T> createClient(
-      final Class<T> serviceType, final String serviceName, final QoSProfile qosProfile)
-      throws NoSuchFieldException, IllegalAccessException {
-    Class<MessageDefinition> requestType = (Class) serviceType.getField("RequestType").get(null);
-
-    Class<MessageDefinition> responseType = (Class) serviceType.getField("ResponseType").get(null);
-
+    final Class<T> serviceType, final String serviceName, final QoSProfile qosProfile)
+  {
     long qosProfileHandle = RCLJava.convertQoSProfileToHandle(qosProfile);
     long clientHandle =
         nativeCreateClientHandle(this.handle, serviceType, serviceName, qosProfileHandle);
     RCLJava.disposeQoSProfile(qosProfileHandle);
 
+    T serviceDefinition;
+    try {
+      serviceDefinition = serviceType.getDeclaredConstructor().newInstance();
+    } catch (ReflectiveOperationException e) {
+      throw new IllegalStateException("Failed to instantiate service definition");
+    }
+
     Client<T> client = new ClientImpl<T>(
-        new WeakReference<Node>(this), clientHandle, serviceName, requestType, responseType);
+        serviceDefinition, new WeakReference<Node>(this), clientHandle, serviceName);
     this.clients.add(client);
 
     return client;
   }
 
   public <T extends ServiceDefinition> Client<T> createClient(final Class<T> serviceType,
-      final String serviceName) throws NoSuchFieldException, IllegalAccessException {
+      final String serviceName) {
     return this.<T>createClient(serviceType, serviceName, QoSProfile.SERVICES_DEFAULT);
   }
 
@@ -531,6 +537,14 @@ public final String getNamespace() {
     return nativeGetNamespace(this.handle);
   }
 
+  public AsyncParametersClient createAsyncParametersClient(String nodeName) {
+    return new AsyncParametersClientImpl(this, nodeName);
+  }
+
+  public SyncParametersClient createSyncParametersClient(String nodeName) {
+    return new SyncParametersClientImpl(this, nodeName);
+  }
+
   public ParameterVariant declareParameter(ParameterVariant parameter) {
     return declareParameter(parameter, new rcl_interfaces.msg.ParameterDescriptor().setName(parameter.getName()));
   }
diff --git a/rcljava/src/main/java/org/ros2/rcljava/parameters/client/AsyncParametersClientImpl.java b/rcljava/src/main/java/org/ros2/rcljava/parameters/client/AsyncParametersClientImpl.java
index bfd01708..5de84b4f 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/parameters/client/AsyncParametersClientImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/parameters/client/AsyncParametersClientImpl.java
@@ -49,7 +49,7 @@ public class AsyncParametersClientImpl implements AsyncParametersClient {
   private final Client<rcl_interfaces.srv.DescribeParameters> describeParametersClient;
 
   public AsyncParametersClientImpl(final Node node, final String remoteName,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException {
+      final QoSProfile qosProfile) {
     this.node = node;
     if (remoteName != "") {
       this.remoteName = remoteName;
@@ -84,17 +84,17 @@ public AsyncParametersClientImpl(final Node node, final String remoteName,
   }
 
   public AsyncParametersClientImpl(final Node node, final QoSProfile qosProfile)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, "", qosProfile);
   }
 
   public AsyncParametersClientImpl(final Node node, final String remoteName)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, remoteName, QoSProfile.PARAMETERS);
   }
 
   public AsyncParametersClientImpl(final Node node)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, "", QoSProfile.PARAMETERS);
   }
 
diff --git a/rcljava/src/main/java/org/ros2/rcljava/parameters/client/SyncParametersClientImpl.java b/rcljava/src/main/java/org/ros2/rcljava/parameters/client/SyncParametersClientImpl.java
index d2b4a78f..b8a0a323 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/parameters/client/SyncParametersClientImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/parameters/client/SyncParametersClientImpl.java
@@ -55,44 +55,55 @@ public ConsumerHelper(RCLFuture<T> resultFuture) {
 
   public AsyncParametersClient asyncParametersClient;
 
-  public SyncParametersClientImpl(final Node node, final String remoteName,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException {
+  public SyncParametersClientImpl(
+    final Node node,
+    final String remoteName,
+    final QoSProfile qosProfile)
+  {
     this.asyncParametersClient = new AsyncParametersClientImpl(node, remoteName, qosProfile);
   }
 
   public SyncParametersClientImpl(final Node node, final QoSProfile qosProfile)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, "", qosProfile);
   }
 
   public SyncParametersClientImpl(final Node node, final String remoteName)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, remoteName, QoSProfile.PARAMETERS);
   }
 
   public SyncParametersClientImpl(final Node node)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(node, "", QoSProfile.PARAMETERS);
   }
 
-  public SyncParametersClientImpl(final Executor executor, final Node node, final String remoteName,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException {
+  public SyncParametersClientImpl(
+    final Executor executor,
+    final Node node,
+    final String remoteName,
+    final QoSProfile qosProfile)
+  {
     this.executor = executor;
     this.asyncParametersClient = new AsyncParametersClientImpl(node, remoteName, qosProfile);
   }
 
-  public SyncParametersClientImpl(final Executor executor, final Node node,
-      final QoSProfile qosProfile) throws NoSuchFieldException, IllegalAccessException {
+  public SyncParametersClientImpl(
+    final Executor executor,
+    final Node node,
+    final QoSProfile qosProfile)
+  {
     this(executor, node, "", qosProfile);
   }
 
-  public SyncParametersClientImpl(final Executor executor, final Node node, final String remoteName)
-      throws NoSuchFieldException, IllegalAccessException {
+  public SyncParametersClientImpl(
+    final Executor executor, final Node node, final String remoteName)
+  {
     this(executor, node, remoteName, QoSProfile.PARAMETERS);
   }
 
   public SyncParametersClientImpl(final Executor executor, final Node node)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this(executor, node, "", QoSProfile.PARAMETERS);
   }
 
diff --git a/rcljava/src/main/java/org/ros2/rcljava/parameters/service/ParameterServiceImpl.java b/rcljava/src/main/java/org/ros2/rcljava/parameters/service/ParameterServiceImpl.java
index 9d65ddd7..bc03b121 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/parameters/service/ParameterServiceImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/parameters/service/ParameterServiceImpl.java
@@ -38,7 +38,7 @@ public class ParameterServiceImpl implements ParameterService {
   Service<rcl_interfaces.srv.ListParameters> listParametersService;
 
   public ParameterServiceImpl(final Node node, final QoSProfile qosProfile)
-      throws NoSuchFieldException, IllegalAccessException {
+  {
     this.node = node;
     this.getParametersService = node.<rcl_interfaces.srv.GetParameters>createService(
         rcl_interfaces.srv.GetParameters.class,
@@ -146,7 +146,7 @@ public void accept(RMWRequestId rmwRequestId,
         qosProfile);
   }
 
-  public ParameterServiceImpl(final Node node) throws NoSuchFieldException, IllegalAccessException {
+  public ParameterServiceImpl(final Node node) {
     this(node, QoSProfile.PARAMETERS);
   }
 }
diff --git a/rcljava/src/main/java/org/ros2/rcljava/service/Service.java b/rcljava/src/main/java/org/ros2/rcljava/service/Service.java
index dfde9a09..289bad2b 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/service/Service.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/service/Service.java
@@ -21,9 +21,7 @@
 import org.ros2.rcljava.interfaces.ServiceDefinition;
 
 public interface Service<T extends ServiceDefinition> extends Disposable {
-  <U extends MessageDefinition> Class<U> getRequestType();
-
-  <U extends MessageDefinition> Class<U> getResponseType();
+  ServiceDefinition getServiceDefinition();
 
   void executeCallback(RMWRequestId rmwRequestId, MessageDefinition request, MessageDefinition response);
 
diff --git a/rcljava/src/main/java/org/ros2/rcljava/service/ServiceImpl.java b/rcljava/src/main/java/org/ros2/rcljava/service/ServiceImpl.java
index 0257813a..960a8424 100644
--- a/rcljava/src/main/java/org/ros2/rcljava/service/ServiceImpl.java
+++ b/rcljava/src/main/java/org/ros2/rcljava/service/ServiceImpl.java
@@ -45,28 +45,25 @@ public class ServiceImpl<T extends ServiceDefinition> implements Service<T> {
   private final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
       callback;
 
-  private final Class<MessageDefinition> requestType;
-  private final Class<MessageDefinition> responseType;
-
-  public ServiceImpl(final WeakReference<Node> nodeReference, final long handle,
-      final String serviceName,
-      final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
-          callback,
-      final Class<MessageDefinition> requestType, final Class<MessageDefinition> responseType) {
+  private final ServiceDefinition serviceDefinition;
+
+  public ServiceImpl(
+    final ServiceDefinition serviceDefinition,
+    final WeakReference<Node> nodeReference,
+    final long handle,
+    final String serviceName,
+    final TriConsumer<RMWRequestId, ? extends MessageDefinition, ? extends MessageDefinition>
+      callback)
+  {
     this.nodeReference = nodeReference;
     this.handle = handle;
     this.serviceName = serviceName;
     this.callback = callback;
-    this.requestType = requestType;
-    this.responseType = responseType;
+    this.serviceDefinition = serviceDefinition;
   }
 
-  public final Class<MessageDefinition> getRequestType() {
-    return this.requestType;
-  }
-
-  public final Class<MessageDefinition> getResponseType() {
-    return this.responseType;
+  public final ServiceDefinition getServiceDefinition() {
+    return this.serviceDefinition;
   }
 
   /**
diff --git a/rcljava_common/src/main/java/org/ros2/rcljava/interfaces/ServiceDefinition.java b/rcljava_common/src/main/java/org/ros2/rcljava/interfaces/ServiceDefinition.java
index 8e3bf79e..cade9a22 100644
--- a/rcljava_common/src/main/java/org/ros2/rcljava/interfaces/ServiceDefinition.java
+++ b/rcljava_common/src/main/java/org/ros2/rcljava/interfaces/ServiceDefinition.java
@@ -15,4 +15,7 @@
 
 package org.ros2.rcljava.interfaces;
 
-public interface ServiceDefinition {}
+public interface ServiceDefinition {
+  MessageDefinition newRequestInstance();
+  MessageDefinition newResponseInstance();
+}
diff --git a/rosidl_generator_java/resource/srv.java.em b/rosidl_generator_java/resource/srv.java.em
index 8bfb887c..a238ecfd 100644
--- a/rosidl_generator_java/resource/srv.java.em
+++ b/rosidl_generator_java/resource/srv.java.em
@@ -61,6 +61,14 @@ public class @(type_name) implements ServiceDefinition {
     }
   }
 
+  public @(type_name)_Request newRequestInstance() {
+    return new @(type_name)_Request();
+  }
+
+  public @(type_name)_Response newResponseInstance() {
+    return new @(type_name)_Response();
+  }
+
   public static native long getServiceTypeSupport();
 
   public static final Class<@(type_name)_Request> RequestType = @(type_name)_Request.class;