WELD-633 Added Weld-Extension BeanManagerProvider SPI impl for Weld-S…

…ervlet

environments/servlet/core/src/main/java/org/jboss/weld/environment/servlet/provider/WeldServletBeanManagerProvider.java

@@ -0,0 +1,133 @@
+package org.jboss.weld.environment.servlet.provider;
+
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.enterprise.inject.spi.BeanManager;
+import javax.enterprise.inject.spi.Extension;
+
+import org.jboss.weld.environment.servlet.util.Reflections;
+import org.jboss.weld.extensions.beanManager.BeanManagerAccessor;
+import org.jboss.weld.extensions.beanManager.BeanManagerProvider;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Implements the Weld Extensions {@link BeanManagerProvider} SPI. Used to get {@link BeanManager}
+ * from outside a Servlet context.
+ * 
+ * @author <a href="mailto:aslak@redhat.com">Aslak Knutsen</a>
+ * @version $Revision: $
+ * @see BeanManagerAccessor
+ * @see BeanManagerProvider
+ */
+public class WeldServletBeanManagerProvider implements BeanManagerProvider, Extension
+{
+   private static String CONTAINER_CLASS_NAME = "org.jboss.weld.Container";
+   private static String CONTAINER_INSTANCE_METHOD = "instance";
+   private static String CONTAINER_AVAILABLE_METHOD = "available";
+   private static String CONTAINER_BEAN_DEPLOYMENT_METHOD = "beanDeploymentArchives";
+   private static String BEAN_DEPLOYMENT_ARCHIVE_ID_METHOD = "getId";
+   private static String BEAN_DEPLOYMENT_ARCHIVE_ID = "flat";
+
+   private static String ERROR_GETTING_BEAN_DEPLOYMENT_ARCHIVES = "Could not get BeanDeploymentArchives from Container";
+   private static String ERROR_CONTAINER_NOT_AVAILABLE = "Container has not been initialized";
+
+   private static final Logger log = LoggerFactory.getLogger(WeldServletBeanManagerProvider.class);
+
+   public int getPrecedence()
+   {
+      return 50;
+   }
+
+   public BeanManager getBeanManager()
+   {
+      Class<?> containerClass = null;
+      try
+      {
+         containerClass = Reflections.classForName(CONTAINER_CLASS_NAME);
+      }
+      catch (IllegalArgumentException e) 
+      {
+         // ClassNotFound, Weld not on ClassPath, move on
+         return null;
+      }
+      try
+      {
+         if(isContainerAvailable(containerClass))
+         {
+            Object container = getAvailableContainer(containerClass);
+            Map<?, ?> beanDeploymentArchives = getBeanDeploymentArchives(containerClass, container);
+            return findBeanDeploymentArchiveById(beanDeploymentArchives, BEAN_DEPLOYMENT_ARCHIVE_ID);
+         }
+         else
+         {
+            log.warn(ERROR_CONTAINER_NOT_AVAILABLE);
+         }
+      }
+      catch (Exception e) 
+      {
+         log.warn(ERROR_GETTING_BEAN_DEPLOYMENT_ARCHIVES, e);
+      }
+      return null;
+   }
+
+   // Container.available()   
+   private boolean isContainerAvailable(Class<?> containerClass) 
+   {
+      Method available = Reflections.findDeclaredMethod(containerClass, CONTAINER_AVAILABLE_METHOD);
+      if(available == null)
+      {
+         throw new IllegalArgumentException("Method " + CONTAINER_AVAILABLE_METHOD + " could not be found on " + containerClass);
+      }
+      return Reflections.invokeMethod(available, Boolean.class, null);
+   }
+
+   // Container.instance()
+   private Object getAvailableContainer(Class<?> containerClass)
+   {
+      Method instance = Reflections.findDeclaredMethod(containerClass, CONTAINER_INSTANCE_METHOD);
+      if(instance == null)
+      {
+         throw new IllegalArgumentException("Method " + CONTAINER_INSTANCE_METHOD + " could not be found on " + containerClass);
+      }
+
+      return Reflections.invokeMethod(instance, Object.class, null);
+   }
+
+   // Container.deploymentManager()
+   private Map<?, ?> getBeanDeploymentArchives(Class<?> containerClass, Object container)
+   {
+      Method deploymentManager = Reflections.findDeclaredMethod(containerClass, CONTAINER_BEAN_DEPLOYMENT_METHOD);
+      if(deploymentManager == null)
+      {
+         throw new IllegalArgumentException("Method " + CONTAINER_BEAN_DEPLOYMENT_METHOD + " could not be found on " + containerClass);
+      }
+
+      return Reflections.invokeMethod(deploymentManager, Map.class, container);
+   }
+
+   // BeanDeploymentArchive.getId()
+   private BeanManager findBeanDeploymentArchiveById(Map<?, ?> beanDeploymentArchives, String id)
+   {
+      for(Entry<?, ?> beanDeploymentEntry : beanDeploymentArchives.entrySet())
+      {
+         Object beanManagerDeployment = beanDeploymentEntry.getKey();
+         Class<?> beanManagerDeploymentClass = beanManagerDeployment.getClass();
+
+         Method getId = Reflections.findDeclaredMethod(beanManagerDeploymentClass, BEAN_DEPLOYMENT_ARCHIVE_ID_METHOD);
+         if(getId == null)
+         {
+            throw new IllegalArgumentException("Method " + BEAN_DEPLOYMENT_ARCHIVE_ID_METHOD + " could not be found on " + beanManagerDeploymentClass);
+         }
+
+         String beanArchiveId = Reflections.invokeMethod(getId, String.class, beanManagerDeployment);
+         if(id.equals(beanArchiveId))
+         {
+            return BeanManager.class.cast(beanDeploymentEntry.getValue());
+         }
+      }
+      return null;
+   }
+}

environments/servlet/core/src/main/resources/META-INF/services/org.jboss.weld.extensions.beanManager.BeanManagerProvider

@@ -0,0 +1 @@
+org.jboss.weld.environment.servlet.provider.WeldServletBeanManagerProvider