[Fix #925] Allow association of additional objects to application

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java

@@ -19,6 +19,7 @@
 
 import io.serverlessworkflow.api.types.SchemaInline;
 import io.serverlessworkflow.api.types.Workflow;
+import io.serverlessworkflow.impl.additional.WorkflowAdditionalObject;
 import io.serverlessworkflow.impl.events.EventConsumer;
 import io.serverlessworkflow.impl.events.EventPublisher;
 import io.serverlessworkflow.impl.events.InMemoryEvents;
@@ -38,6 +39,7 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Optional;
 import java.util.ServiceLoader;
 import java.util.ServiceLoader.Provider;
 import java.util.concurrent.ConcurrentHashMap;
@@ -61,6 +63,7 @@ public class WorkflowApplication implements AutoCloseable {
   private final boolean lifeCycleCEPublishingEnabled;
   private final WorkflowModelFactory modelFactory;
   private final WorkflowScheduler scheduler;
+  private final Map<String, WorkflowAdditionalObject<?>> additionalObjects;
 
   private WorkflowApplication(Builder builder) {
     this.taskFactory = builder.taskFactory;
@@ -78,6 +81,7 @@ private WorkflowApplication(Builder builder) {
     this.lifeCycleCEPublishingEnabled = builder.lifeCycleCEPublishingEnabled;
     this.modelFactory = builder.modelFactory;
     this.scheduler = builder.scheduler;
+    this.additionalObjects = builder.additionalObjects;
   }
 
   public TaskExecutorFactory taskFactory() {
@@ -153,6 +157,7 @@ public SchemaValidator getValidator(SchemaInline inline) {
         () -> new RuntimeDescriptor("reference impl", "1.0.0_alpha", Collections.emptyMap());
     private boolean lifeCycleCEPublishingEnabled = true;
     private WorkflowModelFactory modelFactory;
+    private Map<String, WorkflowAdditionalObject<?>> additionalObjects;
 
     private Builder() {}
 
@@ -221,6 +226,15 @@ public Builder withEventPublisher(EventPublisher eventPublisher) {
       return this;
     }
 
+    public <T> Builder withAdditionalObject(
+        String name, WorkflowAdditionalObject<T> additionalObject) {
+      if (additionalObjects == null) {
+        additionalObjects = new ConcurrentHashMap<>();
+      }
+      additionalObjects.put(name, additionalObject);
+      return this;
+    }
+
     public Builder withModelFactory(WorkflowModelFactory modelFactory) {
       this.modelFactory = modelFactory;
       return this;
@@ -269,6 +283,10 @@ public WorkflowApplication build() {
       if (scheduler == null) {
         scheduler = new DefaultWorkflowScheduler();
       }
+      if (additionalObjects == null) {
+        additionalObjects = Collections.emptyMap();
+      }
+
       return new WorkflowApplication(this);
     }
   }
@@ -329,4 +347,10 @@ public boolean isLifeCycleCEPublishingEnabled() {
   public WorkflowScheduler scheduler() {
     return scheduler;
   }
+
+  public <T> Optional<T> additionalObject(
+      String name, WorkflowContext workflowContext, TaskContext taskContext) {
+    return Optional.ofNullable(additionalObjects.get(name))
+        .map(v -> (T) v.apply(workflowContext, taskContext));
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/additional/ConstantAdditionalObject.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.impl.additional;
+
+import io.serverlessworkflow.impl.TaskContext;
+import io.serverlessworkflow.impl.WorkflowContext;
+
+public class ConstantAdditionalObject<T> implements WorkflowAdditionalObject<T> {
+
+  private final T object;
+
+  public ConstantAdditionalObject(T object) {
+    this.object = object;
+  }
+
+  @Override
+  public T apply(WorkflowContext t, TaskContext u) {
+    return object;
+  }
+}

impl/core/src/main/java/io/serverlessworkflow/impl/additional/SuppliedAdditionalObject.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.impl.additional;
+
+import io.serverlessworkflow.impl.TaskContext;
+import io.serverlessworkflow.impl.WorkflowContext;
+import java.util.function.Supplier;
+
+public class SuppliedAdditionalObject<T> implements WorkflowAdditionalObject<T> {
+
+  private final Supplier<T> supplier;
+
+  public SuppliedAdditionalObject(Supplier<T> supplier) {
+    this.supplier = supplier;
+  }
+
+  @Override
+  public T apply(WorkflowContext t, TaskContext u) {
+    return supplier.get();
+  }
+}

impl/core/src/main/java/io/serverlessworkflow/impl/additional/WorkflowAdditionalObject.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.impl.additional;
+
+import io.serverlessworkflow.impl.TaskContext;
+import io.serverlessworkflow.impl.WorkflowContext;
+import java.util.function.BiFunction;
+
+public interface WorkflowAdditionalObject<T> extends BiFunction<WorkflowContext, TaskContext, T> {}

impl/http/src/main/java/io/serverlessworkflow/impl/executors/http/HttpClientResolver.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.impl.executors.http;
+
+import io.serverlessworkflow.impl.TaskContext;
+import io.serverlessworkflow.impl.WorkflowContext;
+import jakarta.ws.rs.client.Client;
+import jakarta.ws.rs.client.ClientBuilder;
+
+public class HttpClientResolver {
+
+  public static final String HTTP_CLIENT_PROVIDER = "httpClientProvider";
+
+  private static class DefaultHolder {
+    private static final Client client = ClientBuilder.newClient();
+  }
+
+  public static Client client(WorkflowContext workflowContext, TaskContext taskContext) {
+    return workflowContext
+        .definition()
+        .application()
+        .<Client>additionalObject(HTTP_CLIENT_PROVIDER, workflowContext, taskContext)
+        .orElseGet(() -> DefaultHolder.client);
+  }
+
+  private HttpClientResolver() {}
+}

impl/http/src/main/java/io/serverlessworkflow/impl/executors/http/HttpExecutor.java

@@ -34,8 +34,6 @@
 import io.serverlessworkflow.impl.expressions.ExpressionDescriptor;
 import jakarta.ws.rs.HttpMethod;
 import jakarta.ws.rs.WebApplicationException;
-import jakarta.ws.rs.client.Client;
-import jakarta.ws.rs.client.ClientBuilder;
 import jakarta.ws.rs.client.Invocation.Builder;
 import jakarta.ws.rs.client.WebTarget;
 import java.net.URI;
@@ -46,7 +44,6 @@
 
 public class HttpExecutor implements CallableTask<CallHTTP> {
 
-  private static final Client client = ClientBuilder.newClient();
   // TODO allow changing default converter
   private static final HttpModelConverter defaultConverter = new HttpModelConverter() {};
 
@@ -262,13 +259,14 @@ public boolean accept(Class<? extends TaskBase> clazz) {
   }
 
   private static TargetSupplier getTargetSupplier(WorkflowValueResolver<URI> uriSupplier) {
-    return (w, t, n) -> client.target(uriSupplier.apply(w, t, n));
+    return (w, t, n) -> HttpClientResolver.client(w, t).target(uriSupplier.apply(w, t, n));
   }
 
   private static TargetSupplier getTargetSupplier(
       WorkflowValueResolver<URI> uriSupplier, WorkflowValueResolver<URI> pathSupplier) {
     return (w, t, n) ->
-        client.target(uriSupplier.apply(w, t, n).resolve(pathSupplier.apply(w, t, n)));
+        HttpClientResolver.client(w, t)
+            .target(uriSupplier.apply(w, t, n).resolve(pathSupplier.apply(w, t, n)));
   }
 
   private static interface TargetSupplier {