1 files changed, 119 insertions, 0 deletions
diff --git a/qpid/java/management/example/src/main/java/org/apache/qpid/example/jmxexample/DeleteMessagesFromTopOfTmp.java b/qpid/java/management/example/src/main/java/org/apache/qpid/example/jmxexample/DeleteMessagesFromTopOfTmp.java
new file mode 100644
index 0000000000..5d529a8ff6
--- /dev/null
+++ b/qpid/java/management/example/src/main/java/org/apache/qpid/example/jmxexample/DeleteMessagesFromTopOfTmp.java
@@ -0,0 +1,119 @@
+/*
+ *
+ * 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.example.jmxexample;
+
+import java.util.Set;
+
+import javax.management.MBeanServerConnection;
+import javax.management.ObjectName;
+import javax.management.remote.JMXConnector;
+import javax.management.remote.JMXConnectorFactory;
+import javax.management.remote.JMXServiceURL;
+
+/**
+ * Connects to a server and queries all info for tmp_* named queues, determines 
+ * their message count, and if this is above a given threshold deletes the 
+ * specified number of messages from the front of the queue
+ */
+public class DeleteMessagesFromTopOfTmp
+{
+    /**
+     * Params:
+     * 0: host, e.g. myserver.mydomain.com
+     * 1: port, e.g. 8999
+     * 2: Number of messages to delete, e.g. 1000
+     * 3: Threshold MessageCount on queue required before deletion will be undertaken e.g. 5000
+     */
+    public static void main(String[] args) throws Exception
+    {
+        if (args.length < 4)
+        {
+            System.out.println("Usage: ");
+            System.out.println("<host> <port> <numMsgsToDel> <minRequiredQueueMsgCount>");
+            return;
+        }
+
+        String host = args[0];
+        int port = Integer.parseInt(args[1]);
+        int numToDel = Integer.parseInt(args[2]);
+        int numRequired = Integer.parseInt(args[3]);
+
+        deleteFromTop(host, port, numToDel, numRequired);
+    }
+
+    private static void deleteFromTop(String host, int port, 
+                                      int numMsgsToDel, int minRequiredQueueMsgCount) throws Exception
+    {
+        JMXConnector con = getJMXConnection(host, port);
+        MBeanServerConnection mbsc = con.getMBeanServerConnection();
+
+        // Gets all tmp_* queue MBean ObjectNames
+        Set<ObjectName> names = mbsc.queryNames(
+                                new ObjectName("org.apache.qpid:type=VirtualHost.Queue,name=tmp_*,*"), null);
+
+        // Traverse objects and delete specified number of message if the min msg count is breached
+        for (ObjectName queueObjectName : names)
+        {
+            String queueName = queueObjectName.getKeyProperty("name");
+            System.out.println("Checking message count on queue: " + queueName);
+
+            long mc = (Integer) mbsc.getAttribute(queueObjectName, "MessageCount");
+
+            if(mc >= minRequiredQueueMsgCount)
+            {
+                System.out.println("MessageCount (" + mc + ") is above the specified threshold ("
+                                   + minRequiredQueueMsgCount + ")");
+                System.out.println("Deleting first " + numMsgsToDel + " messages on queue: " + queueName);
+
+                int i;
+                for(i=0; i<numMsgsToDel; i++)
+                {
+                    try
+                    {
+                        mbsc.invoke(queueObjectName,"deleteMessageFromTop",null,null);
+                    }
+                    catch(Exception e)
+                    {
+                        System.out.println("Exception whilst deleting message" + i +" from queue: " +e);
+                        break;
+                    }
+                }
+            }
+            else
+            {
+                System.out.println("MessageCount (" + mc + ") is below the specified threshold ("
+                                   + minRequiredQueueMsgCount + ")");
+                System.out.println("Not deleting any messages on queue: " + queueName);
+            }
+        }
+    }
+
+    private static JMXConnector getJMXConnection(String host, int port) throws Exception
+    {
+        //Open JMX connection
+        JMXServiceURL jmxUrl = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://" + host + ":" + port + "/jmxrmi");
+        JMXConnector con = JMXConnectorFactory.connect(jmxUrl);
+        return con;
+    }
+}
+
+
+