Compile under sbt again, simplify API further

build.sbt

@@ -138,7 +138,7 @@ lazy val samples = project
   .aggregate(
     // FIXME include samples again
 //    `java-eventing-shopping-cart`,
-//    `java-customer-registry`
+    `java-customer-registry`
   )
 
 lazy val `java-eventing-shopping-cart` = project

samples/java-customer-registry/src/main/java/customer/CustomerValueEntity.java

@@ -16,20 +16,16 @@
 
 package customer;
 
-import com.akkaserverless.javasdk.Effect;
 import com.akkaserverless.javasdk.valueentity.CommandContext;
 import com.google.protobuf.Empty;
 import customer.api.CustomerApi;
 import customer.domain.CustomerDomain;
 
-import java.util.Optional;
-
 /**
  * This is where the user will implement his business logic.
  *
- * We might generate an initial version, but after that
- * re-generation should update just the interface and the users'
- * build tooling should indicate what needs changing.
+ * <p>We might generate an initial version, but after that re-generation should update just the
+ * interface and the users' build tooling should indicate what needs changing.
  */
 public class CustomerValueEntity extends CustomerValueEntityInterface {
 

samples/java-customer-registry/src/main/java/customer/CustomerValueEntityHandler.java

@@ -16,13 +16,14 @@
 
 package customer;
 
-import com.akkaserverless.javasdk.Effect;
 import com.akkaserverless.javasdk.Reply;
 import com.akkaserverless.javasdk.impl.*;
 import com.akkaserverless.javasdk.impl.valueentity.AdaptedCommandContext;
 import com.akkaserverless.javasdk.lowlevel.ValueEntityHandler;
 import com.akkaserverless.javasdk.valueentity.CommandContext;
+import com.akkaserverless.javasdk.valueentity.ValueEntityBase;
 import com.google.protobuf.Any;
+import com.google.protobuf.Descriptors;
 import com.google.protobuf.GeneratedMessageV3;
 import customer.api.CustomerApi;
 import customer.domain.CustomerDomain;
@@ -33,29 +34,39 @@
 import java.lang.reflect.InvocationTargetException;
 
 /**
- * This class would be generated by codegen and should be
- * treated mostly as an implementation detail by the user.
+ * This class would be generated by codegen and should be treated mostly as an implementation detail
+ * by the user.
  */
 public class CustomerValueEntityHandler implements ValueEntityHandler {
   final CustomerValueEntity entity;
   final AnySupport anySupport;
 
-  CustomerValueEntityHandler(CustomerValueEntity entity, AnySupport anySupport) {
+  public static final Descriptors.ServiceDescriptor serviceDescriptor =
+      CustomerApi.getDescriptor().findServiceByName("CustomerService");
+  public static final String entityType = "customers";
+
+  CustomerValueEntityHandler(CustomerValueEntity entity) {
     this.entity = entity;
-    this.anySupport = anySupport;
+    this.anySupport =
+        new AnySupport(
+            new Descriptors.FileDescriptor[] {CustomerDomain.getDescriptor()},
+            CustomerValueEntityHandler.class.getClassLoader(),
+            AnySupport.DefaultTypeUrlPrefix(),
+            AnySupport.PREFER_JAVA());
   }
 
   @Override
-  public Reply<Any> handleCommand(Any command, Any state, CommandContext<Any> context)
-      throws Throwable {
+  public ValueEntityBase.Effect<Any> handleCommand(
+      Any command, Any state, CommandContext<Any> context) throws Throwable {
     AdaptedCommandContext<CustomerDomain.CustomerState> adaptedContext =
         new AdaptedCommandContext(context, anySupport);
     try {
       CustomerDomain.CustomerState parsedState =
           CustomerDomain.CustomerState.parseFrom(state.getValue());
       // TODO we used to support passing in the command as Jackson-parsed model object
       // or as ScalaPB class as well. With this change we tie ourselves to Java protobuf.
-      Effect<? extends GeneratedMessageV3> effect = invoke(command, parsedState, adaptedContext);
+      ValueEntityBase.Effect<? extends GeneratedMessageV3> effect =
+          invoke(command, parsedState, adaptedContext);
       // TODO we used to support accepting ScalaPB and Jackson objects as responses as well.
       //  Are we OK with losing that? I guess we could have separate methods for that on the
       //  builder, though it's not obvious how to achieve type-safety for those then.
@@ -88,7 +99,7 @@ public com.google.protobuf.any.Any emptyState() {
         UnknownFieldSet.empty());
   }
 
-  public Effect<? extends GeneratedMessageV3> invoke(
+  public ValueEntityBase.Effect<? extends GeneratedMessageV3> invoke(
       Any command,
       CustomerDomain.CustomerState state,
       CommandContext<CustomerDomain.CustomerState> context)

samples/java-customer-registry/src/main/java/customer/CustomerValueEntityInterface.java

@@ -16,19 +16,13 @@
 
 package customer;
 
-import com.akkaserverless.javasdk.Effect;
 import com.akkaserverless.javasdk.valueentity.CommandContext;
 import com.akkaserverless.javasdk.valueentity.ValueEntityBase;
 import com.google.protobuf.Empty;
 import customer.api.CustomerApi;
 import customer.domain.CustomerDomain;
 
-import java.util.Optional;
-
-/**
- * This file would be managed by the codegen and provide
- * the interface the user implements.
- */
+/** This file would be managed by the codegen and provide the interface the user implements. */
 public abstract class CustomerValueEntityInterface
     extends ValueEntityBase<CustomerDomain.CustomerState> {
 

samples/java-customer-registry/src/main/java/customer/Main.java

@@ -40,9 +40,6 @@ public final class Main {
 
   public static void main(String[] args) throws Exception {
     LOG.info("started");
-    ClassLoader classLoader = Main.class.getClassLoader();
-    String typeUrlPrefix = AnySupport.DefaultTypeUrlPrefix();
-    AnySupport.Prefer prefer = AnySupport.PREFER_JAVA();
 
     if (args.length == 0) {
       // This is for value entity
@@ -55,26 +52,10 @@ public static void main(String[] args) throws Exception {
           // end::register[]
           .lowLevel()
           .registerValueEntity(
-              // TODO this factory probably can disappear, we can pass in the handler directly?
-              context ->
-                  new CustomerValueEntityHandler(
-                      // TODO I guess construction the Entity should somehow remain part of the
-                      // customer API, so they can pass
-                      // in  anything they like in the constructor, including the context?
-                      new CustomerValueEntity(),
-                      new AnySupport(
-                          new Descriptors.FileDescriptor[] {CustomerDomain.getDescriptor()},
-                          classLoader,
-                          typeUrlPrefix,
-                          prefer)),
-              CustomerApi.getDescriptor().findServiceByName("CustomerService"),
-              "customers",
-              ValueEntityOptions.defaults(),
-              CustomerDomain.getDescriptor())
-          .registerValueEntity(
-              CustomerValueEntity.class,
-              CustomerApi.getDescriptor().findServiceByName("CustomerService"),
-              CustomerDomain.getDescriptor())
+              context -> new CustomerValueEntityHandler(new CustomerValueEntity()),
+              CustomerValueEntityHandler.serviceDescriptor,
+              CustomerValueEntityHandler.entityType,
+              ValueEntityOptions.defaults())
           .start()
           .toCompletableFuture()
           .get();

sdk/src/main/java/com/akkaserverless/javasdk/AkkaServerless.java

@@ -169,16 +169,13 @@ public AkkaServerless registerAction(
      * @param descriptor The descriptor for the service that this entity implements.
      * @param entityType The entity type name
      * @param entityOptions The options for this entity.
-     * @param additionalDescriptors Any additional descriptors that should be used to look up
-     *     protobuf types when needed.
      * @return This stateful service builder.
      */
     public AkkaServerless registerValueEntity(
         ValueEntityFactory factory,
         Descriptors.ServiceDescriptor descriptor,
         String entityType,
-        ValueEntityOptions entityOptions,
-        Descriptors.FileDescriptor... additionalDescriptors) {
+        ValueEntityOptions entityOptions) {
 
       services.put(
           descriptor.getFullName(),