summaryrefslogtreecommitdiff
path: root/qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java
diff options
context:
space:
mode:
Diffstat (limited to 'qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java')
-rw-r--r--qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java70
1 files changed, 70 insertions, 0 deletions
diff --git a/qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java b/qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java
new file mode 100644
index 0000000000..5a7679a972
--- /dev/null
+++ b/qpid/java/common/src/main/java/org/apache/qpid/protocol/AMQMethodListener.java
@@ -0,0 +1,70 @@
+/*
+ *
+ * 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.protocol;
+
+import org.apache.qpid.framing.AMQMethodBody;
+import org.apache.qpid.AMQException;
+
+/**
+ * AMQMethodListener is a listener that receives notifications of AMQP methods. The methods are packaged as events in
+ * {@link AMQMethodEvent}.
+ *
+ * <p/>An event listener may be associated with a particular context, usually an AMQP channel, and in addition to
+ * receiving method events will be notified of errors on that context. This enables listeners to perform any clean
+ * up that they need to do before the context is closed or retried.
+ *
+ * <p/><table id="crc"><caption>CRC Card</caption>
+ * <tr><th> Responsibilities
+ * <tr><td> Accept notification of AMQP method events. <td> {@link AMQMethodEvent}
+ * <tr><td> Accept notification of errors on the event context.
+ * </table>
+ *
+ * @todo Document why the exception is passed to the error method. Is it so that the exception can be passed
+ * from the event handling thread to another thread and rethown from there? It is unusual to pass exceptions as
+ * method arguments, because they have their own mechanism for propagating through the call stack, so some
+ * explanation ought to be provided.
+ */
+public interface AMQMethodListener
+{
+ /**
+ * Notifies the listener that an AMQP method event has occurred.
+ *
+ * @param evt The AMQP method event (contains the method and channel).
+ *
+ * @return <tt>true</tt> if the handler processes the method frame, <tt>false<tt> otherwise. Note that this does
+ * not prohibit the method event being delivered to subsequent listeners but can be used to determine if
+ * nobody has dealt with an incoming method frame.
+ *
+ * @throws Exception if an error has occurred. This exception may be delivered to all registered listeners using
+ * the error() method (see below) allowing them to perform cleanup if necessary.
+ *
+ * @todo Consider narrowing the exception.
+ */
+ <B extends AMQMethodBody> boolean methodReceived(AMQMethodEvent<B> evt) throws AMQException;
+
+ /**
+ * Notifies the listener of an error on the event context to which it is listening. The listener should perform
+ * any necessary clean-up for the context.
+ *
+ * @param e The underlying exception that is the source of the error.
+ */
+ void error(Exception e);
+}