[camel] 04/18: CAMEL-13636: camel3 - SPI for ReactiveHelper so we can plugin different reactive engines

[da...@apache.org]

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davsclaus pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/camel.git

commit f96f3ab5c66adfd6cfc94b1c8dc22b5c85aab671
Author: Claus Ibsen <cl...@gmail.com>
AuthorDate: Wed Jun 12 13:57:26 2019 +0200

    CAMEL-13636: camel3 - SPI for ReactiveHelper so we can plugin different reactive engines
---
 .../camel/impl/engine/AbstractCamelContext.java    |  5 +-
 .../camel/impl/engine/DefaultReactiveExecutor.java |  3 +
 .../impl/engine/ReactiveExecutorResolver.java      | 73 ++++++++++++++++++++++
 .../org/apache/camel/impl/DefaultCamelContext.java |  3 +-
 4 files changed, 81 insertions(+), 3 deletions(-)

diff --git a/core/camel-base/src/main/java/org/apache/camel/impl/engine/AbstractCamelContext.java b/core/camel-base/src/main/java/org/apache/camel/impl/engine/AbstractCamelContext.java
index 4606bc3..01f5d6e 100644
--- a/core/camel-base/src/main/java/org/apache/camel/impl/engine/AbstractCamelContext.java
+++ b/core/camel-base/src/main/java/org/apache/camel/impl/engine/AbstractCamelContext.java
@@ -3256,6 +3256,8 @@ public abstract class AbstractCamelContext extends ServiceSupport implements Ext
     }
 
     protected void doStartEagerServices() {
+        getFactoryFinderResolver();
+        getDefaultFactoryFinder();
         getComponentResolver();
         getDataFormatResolver();
         getManagementStrategy();
@@ -3264,8 +3266,6 @@ public abstract class AbstractCamelContext extends ServiceSupport implements Ext
         getNodeIdFactory();
         getProcessorFactory();
         getMessageHistoryFactory();
-        getFactoryFinderResolver();
-        getDefaultFactoryFinder();
         getStreamCachingStrategy();
         getModelJAXBContextFactory();
         getUuidGenerator();
@@ -3274,6 +3274,7 @@ public abstract class AbstractCamelContext extends ServiceSupport implements Ext
         getBeanProxyFactory();
         getBeanProcessorFactory();
         getBeanPostProcessor();
+        getReactiveExecutor();
     }
 
     /**
diff --git a/core/camel-base/src/main/java/org/apache/camel/impl/engine/DefaultReactiveExecutor.java b/core/camel-base/src/main/java/org/apache/camel/impl/engine/DefaultReactiveExecutor.java
index d700e3c..0448037 100644
--- a/core/camel-base/src/main/java/org/apache/camel/impl/engine/DefaultReactiveExecutor.java
+++ b/core/camel-base/src/main/java/org/apache/camel/impl/engine/DefaultReactiveExecutor.java
@@ -25,6 +25,9 @@ import org.apache.camel.support.ReactiveHelper;
  */
 public class DefaultReactiveExecutor implements ReactiveExecutor {
 
+    // TODO: ReactiveHelper code should be moved here and not static
+    // ppl should use the SPI interface
+
     @Override
     public void scheduleMain(Runnable runnable) {
         ReactiveHelper.scheduleMain(runnable);
diff --git a/core/camel-base/src/main/java/org/apache/camel/impl/engine/ReactiveExecutorResolver.java b/core/camel-base/src/main/java/org/apache/camel/impl/engine/ReactiveExecutorResolver.java
new file mode 100644
index 0000000..3a78412
--- /dev/null
+++ b/core/camel-base/src/main/java/org/apache/camel/impl/engine/ReactiveExecutorResolver.java
@@ -0,0 +1,73 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.camel.impl.engine;
+
+import java.io.IOException;
+
+import org.apache.camel.CamelContext;
+import org.apache.camel.ExtendedCamelContext;
+import org.apache.camel.spi.FactoryFinder;
+import org.apache.camel.spi.ReactiveExecutor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Factory resolver to create the {@link org.apache.camel.spi.ReactiveExecutor} to be used.
+ */
+public class ReactiveExecutorResolver {
+
+    public static final String RESOURCE_PATH = "META-INF/services/org/apache/camel/";
+
+    private static final Logger LOG = LoggerFactory.getLogger(ReactiveExecutorResolver.class);
+
+    private FactoryFinder factoryFinder;
+
+    public ReactiveExecutor resolve(CamelContext context) {
+        // use factory finder to find a custom implementations
+        Class<?> type = null;
+        try {
+            type = findFactory("reactive-executor-factory", context);
+        } catch (Exception e) {
+            // ignore
+        }
+
+        if (type != null) {
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Found ReactiveExecutor: {} via: {}{}", type.getName(), factoryFinder.getResourcePath(), "reactive-executor-factory");
+            }
+            if (ReactiveExecutor.class.isAssignableFrom(type)) {
+                ReactiveExecutor answer = (ReactiveExecutor) context.getInjector().newInstance(type, false);
+                LOG.debug("Detected and using ReactiveExecutor: {}", answer);
+                return answer;
+            } else {
+                throw new IllegalArgumentException("Type is not a ReactiveExecutor implementation. Found: " + type.getName());
+            }
+        }
+
+        // fallback to default
+        LOG.debug("Creating default ReactiveExecutor");
+        return new DefaultReactiveExecutor();
+    }
+
+    private Class<?> findFactory(String name, CamelContext context) throws ClassNotFoundException, IOException {
+        if (factoryFinder == null) {
+            factoryFinder = context.adapt(ExtendedCamelContext.class).getFactoryFinder(RESOURCE_PATH);
+        }
+        return factoryFinder.findClass(name);
+    }
+
+}
diff --git a/core/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java b/core/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
index 1cce2b8..ee0a939 100644
--- a/core/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
+++ b/core/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
@@ -53,6 +53,7 @@ import org.apache.camel.impl.engine.DefaultUnitOfWorkFactory;
 import org.apache.camel.impl.engine.DefaultUuidGenerator;
 import org.apache.camel.impl.engine.EndpointKey;
 import org.apache.camel.impl.engine.HeadersMapFactoryResolver;
+import org.apache.camel.impl.engine.ReactiveExecutorResolver;
 import org.apache.camel.impl.engine.RestRegistryFactoryResolver;
 import org.apache.camel.impl.engine.ServicePool;
 import org.apache.camel.impl.engine.WebSpherePackageScanClassResolver;
@@ -308,6 +309,6 @@ public class DefaultCamelContext extends AbstractModelCamelContext {
     }
 
     protected ReactiveExecutor createReactiveExecutor() {
-        return new DefaultReactiveExecutor();
+        return new ReactiveExecutorResolver().resolve(this);
     }
 }