QPID-1938 - Make the Java Agent more friendly for inclusion by JBoss Deployer

Patch from Bryan Kearney


git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@795198 13f79535-47bb-0310-9956-ffa450edef68

14 files changed, 182 insertions, 70 deletions

diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/Agent.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/Agent.java
index 823bda7dca..40797d51f9 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/Agent.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/Agent.java
@@ -54,33 +54,34 @@ import org.apache.qpid.transport.codec.BBEncoder;
 import org.apache.qpid.transport.codec.Decoder;
 
 /**
- * The main class for interacting with the QMF bus. Objects which are
- * to be managed can be registered with the agent, as can classes
- * to be exposed via the schema.
+ * The main class for interacting with the QMF bus. Objects which are to be
+ * managed can be registered with the agent, as can classes to be exposed via
+ * the schema.
  */
 public class Agent implements MessageListener
 {
     // The following are settings to configure the Agent
-    private AMQConnection connection;
-    private boolean sessionTransacted = false;
-    private int acknowledgeMode = Session.AUTO_ACKNOWLEDGE;
-    private String label;
-    private UUID systemId;
+    protected AMQConnection connection;
+    protected boolean sessionTransacted = false;
+    protected int acknowledgeMode = Session.AUTO_ACKNOWLEDGE;
+    protected String label;
+    protected UUID systemId;
     // this list holds the objects until the agent is started
-    private List managedObjects = new ArrayList();
-    private List registeredClasses = new ArrayList();
+    protected List managedObjects = new ArrayList();
+    protected List registeredClasses = new ArrayList();
     // The following instance variables are not
     // able to be set by the end user.
-    private Session session;
-    private MessageProducer prod;
-    private MessageConsumer cons;
-    private Queue reply;
-    private BindingContext bctx = new BindingContext();
-    private Map<Long, ManagedObject> objects = new Hashtable<Long, ManagedObject>();
-    private long bbank;
-    private long abank;
-    private static Log log = LogFactory.getLog(Agent.class);
-    private volatile boolean inside = false;
+    protected Session session;
+    protected MessageProducer prod;
+    protected MessageConsumer cons;
+    protected Queue reply;
+    protected BindingContext bctx = new BindingContext();
+    protected Map<Long, ManagedObject> objects = new Hashtable<Long, ManagedObject>();
+    protected long bbank;
+    protected long abank;
+    protected static Log log = LogFactory.getLog(Agent.class);
+    protected volatile boolean inside = false;
+    protected ClassLoader classLoader = null;
 
     public Agent()
     {
@@ -97,7 +98,6 @@ public class Agent implements MessageListener
                 systemId.toString()));
     }
 
-
     public void register(ManagedObject managedObject)
     {
         Class managedClass = managedObject.getObjectClass();
@@ -123,8 +123,26 @@ public class Agent implements MessageListener
     }
 
     /**
-     * Starts up the agent. Many bean containers may call this by
-     * default which aids in deployment
+     * Stops the agents connection to the bus
+     */
+    public void stop()
+    {
+        try
+        {
+            cons.close();
+            prod.close();
+            connection.stop();
+            connection.close();
+            session.close();
+        } catch (JMSException e)
+        {
+            log.error("Exception:", e);
+        }
+    }
+
+    /**
+     * Starts up the agent. Many bean containers may call this by default which
+     * aids in deployment
      */
     public void start()
     {
@@ -134,7 +152,14 @@ public class Agent implements MessageListener
         {
             try
             {
-                Class cls = Class.forName(clsName.toString());
+                Class cls = null;
+                if (String.class.isAssignableFrom(clsName.getClass()))
+                {
+                    cls = getClass(clsName.toString());
+                } else
+                {
+                    cls = (Class) clsName;
+                }
                 this.registerClass(cls);
             } catch (Exception e)
             {
@@ -149,7 +174,11 @@ public class Agent implements MessageListener
         {
             session = connection.createSession(sessionTransacted,
                     acknowledgeMode);
-            reply = session.createQueue(String.format("direct://amq.direct//%s-%s?exclusive='True'&autodelete='True'",label,systemId));
+            reply = session
+                    .createQueue(String
+                            .format(
+                                    "direct://amq.direct//%s-%s?exclusive='True'&autodelete='True'",
+                                    label, systemId));
             cons = session.createConsumer(reply);
             cons.setMessageListener(this);
             prod = session.createProducer(null);
@@ -360,10 +389,11 @@ public class Agent implements MessageListener
                 } catch (BindingException ex)
                 {
                     log
-                            .error(String
-                                    .format(
-                                            "An exception occured invoking method %s. Stack trace sent to console.",
-                                            method.getName()));
+                            .error(
+                                    String
+                                            .format(
+                                                    "An exception occured invoking method %s. Stack trace sent to console.",
+                                                    method.getName()), ex);
                     StringWriter str = new StringWriter();
                     PrintWriter writer = new PrintWriter(str);
                     ex.printStackTrace(writer);
@@ -492,7 +522,7 @@ public class Agent implements MessageListener
         }
     }
 
-    private void attachRequest(String label, UUID systemId)
+    protected void attachRequest(String label, UUID systemId)
     {
         BBEncoder enc = init('A');
         enc.writeStr8(label);
@@ -502,14 +532,14 @@ public class Agent implements MessageListener
         send(enc);
     }
 
-    private void packageIndication(String pkg)
+    protected void packageIndication(String pkg)
     {
         BBEncoder enc = init('p');
         enc.writeStr8(pkg);
         send(enc);
     }
 
-    private void classIndication(ClassBinding cb)
+    protected void classIndication(ClassBinding cb)
     {
         BBEncoder enc = init('q');
         enc.writeUint8(cb.getKind());
@@ -519,14 +549,14 @@ public class Agent implements MessageListener
         send(enc);
     }
 
-    private void schemaResponse(long seq, ClassBinding cb)
+    protected void schemaResponse(long seq, ClassBinding cb)
     {
         BBEncoder enc = init('s', seq);
         cb.encode(enc);
         send(enc);
     }
 
-    private void content(char c, long seq, Destination dest, ManagedObject mo)
+    protected void content(char c, long seq, Destination dest, ManagedObject mo)
     {
         BBEncoder enc = init(c, seq);
         ClassBinding cb = getClassBinding(mo);
@@ -555,7 +585,7 @@ public class Agent implements MessageListener
         }
     }
 
-    private void complete(long seq, Destination dest)
+    protected void complete(long seq, Destination dest)
     {
         BBEncoder enc = init('z', seq);
         enc.writeUint32(0);
@@ -563,13 +593,13 @@ public class Agent implements MessageListener
         send(dest, enc);
     }
 
-    private void methodResponse(long seq, Destination dest, int status,
+    protected void methodResponse(long seq, Destination dest, int status,
             String text)
     {
         methodResponse(seq, dest, status, text, null, null);
     }
 
-    private void methodResponse(long seq, Destination dest, int status,
+    protected void methodResponse(long seq, Destination dest, int status,
             String text, MethodBinding method, Object[] result)
     {
         BBEncoder enc = init('m', seq);
@@ -586,6 +616,24 @@ public class Agent implements MessageListener
         send(dest, enc);
     }
 
+    protected Class getClass(String className)
+    {
+        try
+        {
+            if (classLoader != null)
+            {
+                return classLoader.loadClass(className);
+            } else
+            {
+                return Class.forName(className);
+            }
+        } catch (ClassNotFoundException e)
+        {
+            throw new AgentException(String.format(
+                    "No class named %s was found", className), e);
+        }
+    }
+
     public String getLabel()
     {
         return label;
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/AgentException.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/AgentException.java
index ed189d2bc0..410cad2d8c 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/AgentException.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/AgentException.java
@@ -22,10 +22,12 @@ package org.apache.qpid.agent;
 
 /**
  * AgentException
- * 
+ *
  */
 public class AgentException extends RuntimeException
 {
+    private static final long serialVersionUID = 1L;
+
     public AgentException(String msg)
     {
         super(msg);
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedEJB.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedEJB.java
index 4c5bc594d3..60efb1e284 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedEJB.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedEJB.java
@@ -23,30 +23,42 @@ package org.apache.qpid.agent;
 import javax.naming.InitialContext;
 import javax.naming.NamingException;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.qpid.agent.binding.BindingUtils;
 import org.apache.qpid.agent.binding.MethodBinding;
 import org.apache.qpid.agent.binding.PropertyBinding;
 
 /**
- * Wrapper classe for adding EJBS which are to be 
- * managed by the QMF Agent. The jndi location and the
- * public interface to exposed are used to generate the schema.
+ * Wrapper classe for adding EJBS which are to be managed by the QMF Agent. The
+ * jndi location and the public interface to exposed are used to generate the
+ * schema.
  */
 public class ManagedEJB extends ManagedObjectBase
 {
+    private Log log = LogFactory.getLog(ManagedEJB.class);
     protected String className;
     protected String jndiLocation;
+    protected ClassLoader classLoader;
 
     protected Object getEJB()
     {
+        ClassLoader previousCL = Thread.currentThread().getContextClassLoader();
         try
         {
+            if (classLoader != null)
+            {
+                Thread.currentThread().setContextClassLoader(classLoader);
+            }
             InitialContext ctx = new InitialContext();
             return ctx.lookup(jndiLocation);
         } catch (NamingException e)
         {
             throw new AgentException("Error looking up EJB at " + jndiLocation,
                     e);
+        } finally
+        {
+            Thread.currentThread().setContextClassLoader(previousCL);
         }
     }
 
@@ -67,7 +79,14 @@ public class ManagedEJB extends ManagedObjectBase
     {
         try
         {
-            return Class.forName(className);
+            if (classLoader != null)
+            {
+                log.debug("Using the classloader");
+                return classLoader.loadClass(className);
+            } else
+            {
+                return Class.forName(className);
+            }
         } catch (ClassNotFoundException e)
         {
             throw new AgentException(String.format(
@@ -106,4 +125,14 @@ public class ManagedEJB extends ManagedObjectBase
     {
         this.jndiLocation = jndiLocation;
     }
+
+    public ClassLoader getClassLoader()
+    {
+        return classLoader;
+    }
+
+    public void setClassLoader(ClassLoader cloader)
+    {
+        this.classLoader = cloader;
+    }
 }
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedPOJO.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedPOJO.java
index 061334b252..94d9b9d0a8 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedPOJO.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/ManagedPOJO.java
@@ -27,8 +27,7 @@ import org.apache.qpid.agent.binding.MethodBinding;
 import org.apache.qpid.agent.binding.PropertyBinding;
 
 /**
- * Wrapper classe for adding POJOS which are to be 
- * managed by the QMF Agent. 
+ * Wrapper classe for adding POJOS which are to be managed by the QMF Agent.
  */
 public class ManagedPOJO extends ManagedObjectBase implements ManagedObject
 {
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFAgent.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFAgent.java
new file mode 100644
index 0000000000..b9fcf40fc1
--- /dev/null
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFAgent.java
@@ -0,0 +1,34 @@
+/*
+ *
+ * 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.qpid.agent.annotations;
+
+import java.lang.annotation.Target;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Target(ElementType.FIELD)
+@Retention(RUNTIME)
+@Documented
+public @interface QMFAgent
+{
+}
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFEvent.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFEvent.java
index 319c471445..314f2a7e68 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFEvent.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFEvent.java
@@ -28,9 +28,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
 /**
- * Tells the QMF Agent that this object will be passed as a
- * QMF event. This will cause only properties to be sent across
- * the wire.
+ * Tells the QMF Agent that this object will be passed as a QMF event. This will
+ * cause only properties to be sent across the wire.
  */
 @Target(TYPE)
 @Retention(RUNTIME)
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFHide.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFHide.java
index f3824ff228..db6cb0412f 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFHide.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFHide.java
@@ -28,8 +28,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
 /**
- * Causes the property which is annotated to not be added to the
- * QMF schema when it is built.
+ * Causes the property which is annotated to not be added to the QMF schema when
+ * it is built.
  */
 @Target(ElementType.METHOD)
 @Retention(RUNTIME)
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFObject.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFObject.java
index d737dbb852..7d1713cdbe 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFObject.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFObject.java
@@ -28,9 +28,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
 /**
- * Tells the QMF Agent that this object will be a managed 
- * object. This will allow users to query for it, as well as
- * invoke methods on it.
+ * Tells the QMF Agent that this object will be a managed object. This will
+ * allow users to query for it, as well as invoke methods on it.
  */
 @Target(TYPE)
 @Retention(RUNTIME)
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFSeeAlso.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFSeeAlso.java
index c14ea11ca4..bb9b87805d 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFSeeAlso.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFSeeAlso.java
@@ -28,8 +28,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
 /**
- * Augements the schema generation process to look for known
- * subclasses of a type. Modeled after the JAXB @XMLSeeAlso.
+ * Augements the schema generation process to look for known subclasses of a
+ * type. Modeled after the JAXB @XMLSeeAlso.
  */
 @Target(TYPE)
 @Retention(RUNTIME)
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFType.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFType.java
index 5d43276a55..8da1e15124 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFType.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/annotations/QMFType.java
@@ -28,9 +28,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
 /**
- * Tells the QMF Agent that this object will be a type only
- * This will cause only properties to be sent across
- * the wire.
+ * Tells the QMF Agent that this object will be a type only This will cause only
+ * properties to be sent across the wire.
  */
 @Target(TYPE)
 @Retention(RUNTIME)
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/BindingContext.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/BindingContext.java
index aa84b9dd54..835fed0ce1 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/BindingContext.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/BindingContext.java
@@ -33,8 +33,8 @@ import org.apache.qpid.agent.annotations.QMFSeeAlso;
 import org.apache.qpid.agent.annotations.QMFType;
 
 /**
- * Contains the mappings from java classes to QMF schema and back.
- * There is one context per agent, and it contains all the metadata.
+ * Contains the mappings from java classes to QMF schema and back. There is one
+ * context per agent, and it contains all the metadata.
  */
 public class BindingContext
 {
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/EnumBinding.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/EnumBinding.java
index d2010dfed1..dcb619b736 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/EnumBinding.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/EnumBinding.java
@@ -65,17 +65,20 @@ public class EnumBinding extends ClassBinding
     {
         // FIXME This only works with POJOs
         Object instance = null;
-        String value = null ;        
+        String value = null;
         try
         {
             value = dec.readStr16();
-            if ((value != null ) && (!value.isEmpty())) {
-                instance = Enum.valueOf((Class<Enum>) this.getJavaClass(), value);
-            } 
+            if ((value != null) && (!value.isEmpty()))
+            {
+                instance = Enum.valueOf((Class<Enum>) this.getJavaClass(),
+                        value);
+            }
         } catch (Exception e)
         {
-            log.error(String.format("Could not create an enum of type %s with value %s",
-                    this.javaClass.getName(),value ));
+            log.error(String.format(
+                    "Could not create an enum of type %s with value %s",
+                    this.javaClass.getName(), value));
             throw new BindingException(e);
         }
         return instance;
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/ListBinding.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/ListBinding.java
index 0de8a07107..a3658a812c 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/ListBinding.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/ListBinding.java
@@ -49,7 +49,8 @@ public class ListBinding implements TypeBinding
     {
         List list = (List) value;
         BBEncoder newEncoder = new BBEncoder(10);
-        if (list != null) {
+        if (list != null)
+        {
             newEncoder.writeUint32(list.size());
             for (Object obj : list)
             {
@@ -57,9 +58,9 @@ public class ListBinding implements TypeBinding
                 newEncoder.writeUint8(type.getCode());
                 type.encode(newEncoder, obj);
             }
-        }
-        else {
-            newEncoder.writeUint32(0) ;
+        } else
+        {
+            newEncoder.writeUint32(0);
         }
         enc.writeVbin32(newEncoder.buffer().array());
     }
diff --git a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/PropertyBinding.java b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/PropertyBinding.java
index 22ad8cd8e4..604d66c818 100644
--- a/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/PropertyBinding.java
+++ b/qpid/java/management/agent/src/main/java/org/apache/qpid/agent/binding/PropertyBinding.java
@@ -27,7 +27,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.qpid.transport.codec.Encoder;
 
-
 /**
  * Metadata for mapping a java property (getter/setter) to a QMF schema
  */