CAMEL-13243: Main class should be more easier to use, so lets drop th…

…e confusing multiple CamelContext stuff that was not really intended/working.

MIGRATION.md

@@ -126,6 +126,10 @@ In Camel 2.x we have deprecated `getProperties` on `CamelContext` in favour of `
     </globalOptions>
 
 
+### Main class
+
+The `Main` class from `camel-core`, `camel-spring` and `camel-cdi` has been modified to only support a single `CamelContext` which was really its intention, but there was some old crufy code for multiple Camels. The method `getCamelContextMap` has been removed, and there is just a `getCamelContext` method now.
+
 ### Moved APIs
 
 The following API changes may affect your existing Camel applications, which needs to be migrated.

components/camel-cdi/src/main/java/org/apache/camel/cdi/Main.java

@@ -18,11 +18,6 @@
 
 import java.util.Map;
 import java.util.Set;
-
-import static java.util.function.Function.identity;
-import static java.util.stream.Collectors.toMap;
-
-import javax.enterprise.inject.UnsatisfiedResolutionException;
 import javax.enterprise.inject.spi.Bean;
 import javax.enterprise.inject.spi.BeanManager;
 
@@ -33,9 +28,10 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static java.util.function.Function.identity;
+import static java.util.stream.Collectors.toMap;
 import static org.apache.camel.cdi.AnyLiteral.ANY;
 import static org.apache.camel.cdi.BeanManagerHelper.getReference;
-import static org.apache.camel.cdi.BeanManagerHelper.getReferenceByType;
 import static org.apache.deltaspike.cdise.api.CdiContainerLoader.getCdiContainer;
 
 /**
@@ -75,19 +71,24 @@ public static Main getInstance() {
 
     @Override
     protected ProducerTemplate findOrCreateCamelTemplate() {
-        return getReferenceByType(cdiContainer.getBeanManager(), CamelContext.class)
-            .orElseThrow(
-                () -> new UnsatisfiedResolutionException("No default Camel context is deployed, "
-                    + "cannot create default ProducerTemplate!"))
-            .createProducerTemplate();
+        if (getCamelContext() == null) {
+            throw new IllegalArgumentException("No CamelContext are available so cannot create a ProducerTemplate!");
+        }
+        return getCamelContext().createProducerTemplate();
     }
 
     @Override
-    protected Map<String, CamelContext> getCamelContextMap() {
+    protected CamelContext createCamelContext() {
         BeanManager manager = cdiContainer.getBeanManager();
-        return manager.getBeans(CamelContext.class, ANY).stream()
+        Map<String, CamelContext> camels = manager.getBeans(CamelContext.class, ANY).stream()
             .map(bean -> getReference(manager, CamelContext.class, bean))
             .collect(toMap(CamelContext::getName, identity()));
+        if (camels.size() > 1) {
+            throw new IllegalArgumentException("Multiple CamelContext detected. This Main class only supports single CamelContext");
+        } else if (camels.size() == 1) {
+            return camels.values().iterator().next();
+        }
+        return null;
     }
 
     @Override
@@ -98,7 +99,7 @@ protected void doStart() throws Exception {
         container.getContextControl().startContexts();
         cdiContainer = container;
         super.doStart();
-        postProcessContext();
+        initCamelContext();
         warnIfNoCamelFound();
     }
 

components/camel-spring-boot/src/main/java/org/apache/camel/spring/boot/CamelSpringBootApplicationController.java

@@ -16,8 +16,6 @@
  */
 package org.apache.camel.spring.boot;
 
-import java.util.Collections;
-import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import javax.annotation.PreDestroy;
@@ -45,8 +43,8 @@ protected ProducerTemplate findOrCreateCamelTemplate() {
             }
 
             @Override
-            protected Map<String, CamelContext> getCamelContextMap() {
-                return Collections.singletonMap("camelContext", camelContext);
+            protected CamelContext createCamelContext() {
+                return camelContext;
             }
 
             @Override

components/camel-spring/src/main/java/org/apache/camel/spring/Main.java

@@ -22,7 +22,6 @@
 import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.Enumeration;
-import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.Map;
@@ -144,6 +143,17 @@ public void setParentApplicationContextUri(String parentApplicationContextUri) {
     // Implementation methods
     // -------------------------------------------------------------------------
 
+    @Override
+    protected CamelContext createCamelContext() {
+        Map<String, SpringCamelContext> camels = applicationContext.getBeansOfType(SpringCamelContext.class);
+        if (camels.size() > 1) {
+            throw new IllegalArgumentException("Multiple CamelContext detected. This Main class only supports single CamelContext");
+        } else if (camels.size() == 1) {
+            return camels.values().iterator().next();
+        }
+        return null;
+    }
+
     @Override
     protected void doStart() throws Exception {
         try {
@@ -164,13 +174,11 @@ protected void doStart() throws Exception {
             LOG.debug("Starting Spring ApplicationContext: {}", applicationContext.getId());
             applicationContext.start();
 
-            postProcessContext();
+            initCamelContext();
         } finally {
-            if (camelContexts != null && !camelContexts.isEmpty()) {
-                // if we were veto started then mark as completed
-                if (getCamelContexts().get(0).isVetoStarted()) {
-                    completed();
-                }
+            // if we were veto started then mark as completed
+            if (getCamelContext() != null && getCamelContext().isVetoStarted()) {
+                completed();
             }
         }
     }
@@ -192,10 +200,10 @@ protected ProducerTemplate findOrCreateCamelTemplate() {
         if (names != null && names.length > 0) {
             return getApplicationContext().getBean(names[0], ProducerTemplate.class);
         }
-        if (getCamelContexts().isEmpty()) {
-            throw new IllegalArgumentException("No CamelContexts are available so cannot create a ProducerTemplate!");
+        if (getCamelContext() == null) {
+            throw new IllegalArgumentException("No CamelContext are available so cannot create a ProducerTemplate!");
         }
-        return getCamelContexts().get(0).createProducerTemplate();
+        return getCamelContext().createProducerTemplate();
     }
 
     protected AbstractApplicationContext createDefaultApplicationContext() throws IOException {
@@ -221,18 +229,6 @@ protected AbstractApplicationContext createDefaultApplicationContext() throws IO
         }
     }
 
-    protected Map<String, CamelContext> getCamelContextMap() {
-        Map<String, SpringCamelContext> map = applicationContext.getBeansOfType(SpringCamelContext.class);
-        Set<Map.Entry<String, SpringCamelContext>> entries = map.entrySet();
-        Map<String, CamelContext> answer = new HashMap<>();
-        for (Map.Entry<String, SpringCamelContext> entry : entries) {
-            String name = entry.getKey();
-            CamelContext camelContext = entry.getValue();
-            answer.put(name, camelContext);
-        }
-        return answer;
-    }
-
     protected AbstractApplicationContext createAdditionalLocationsFromClasspath() throws IOException {
         Set<String> locations = new LinkedHashSet<>();
         findLocations(locations, Main.class.getClassLoader());

components/camel-spring/src/test/java/org/apache/camel/spring/MainTest.java

@@ -43,10 +43,7 @@ public void configure() throws Exception {
         });
         main.start();
 
-        List<CamelContext> contextList = main.getCamelContexts();
-        assertNotNull(contextList);
-        assertEquals("size", 1, contextList.size());
-        CamelContext camelContext = contextList.get(0);
+        CamelContext camelContext = main.getCamelContext();
 
         MockEndpoint endpoint = camelContext.getEndpoint("mock:results", MockEndpoint.class);
         // in case we add more files in src/test/data