add a resource.manager.instance property

git-svn-id: https://svn.apache.org/repos/asf/velocity/engine/trunk@1760348 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 28 insertions, 4 deletions

diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeConstants.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeConstants.java
index 3c2b1c46..050cb258 100644
--- a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeConstants.java
+++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeConstants.java
@@ -115,7 +115,16 @@ public interface RuntimeConstants
      * ----------------------------------------------------------------------
      */
 
-    /**  */
+    /**
+     * The <code>resource.manager.instance</code> property specifies an existing instance of a
+     * {@link org.apache.velocity.runtime.resource.ResourceManager} implementation to use
+     */
+    String RESOURCE_MANAGER_INSTANCE = "resource.manager.instance";
+
+    /**
+    * The <code>resource.manager.class</code> property specifies the name of the
+    * {@link org.apache.velocity.runtime.resource.ResourceManager} implementation to use.
+    */
     String RESOURCE_MANAGER_CLASS = "resource.manager.class";
 
     /**
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeInstance.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeInstance.java
index 09a986f7..f2c3fb29 100644
--- a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeInstance.java
+++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/RuntimeInstance.java
@@ -752,9 +752,24 @@ public class RuntimeInstance implements RuntimeConstants, RuntimeServices
         /*
          * Which resource manager?
          */
+        Object inst = getProperty(RuntimeConstants.RESOURCE_MANAGER_INSTANCE);
         String rm = getString(RuntimeConstants.RESOURCE_MANAGER_CLASS);
 
-        if (rm != null && rm.length() > 0)
+        if (inst != null)
+        {
+            if (ResourceManager.class.isAssignableFrom(inst.getClass()))
+            {
+                resourceManager = (ResourceManager)inst;
+                resourceManager.initialize(this);
+            }
+            else
+            {
+                String msg = inst.getClass().getName() + " object set as resource.manager.instance is not a valid org.apache.velocity.runtime.resource.ResourceManager.";
+                log.error(msg);
+                throw new VelocityException(msg);
+            }
+        }
+        else if (rm != null && rm.length() > 0)
         {
             /*
              *  if something was specified, then make one.
@@ -795,8 +810,8 @@ public class RuntimeInstance implements RuntimeConstants, RuntimeServices
             }
 
             resourceManager = (ResourceManager) o;
-
             resourceManager.initialize(this);
+            setProperty(RESOURCE_MANAGER_INSTANCE, resourceManager);
          }
          else
          {
@@ -804,7 +819,7 @@ public class RuntimeInstance implements RuntimeConstants, RuntimeServices
              *  someone screwed up.  Lets not fool around...
              */
 
-            String err = "It appears that no class was specified as the"
+            String err = "It appears that no class or instance was specified as the"
             + " ResourceManager.  Please ensure that all configuration"
             + " information is correct.";