https://issues.apache.org/jira/browse/AMQ-3100 - refactoring to use ServiceLoader

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1052501 13f79535-47bb-0310-9956-ffa450edef68

activemq-core/src/main/java/org/apache/activemq/broker/jmx/AnnotatedMBean.java

@@ -17,6 +17,7 @@
 package org.apache.activemq.broker.jmx;
 
 import org.apache.activemq.broker.util.AuditLog;
+import org.apache.activemq.broker.util.AuditLogService;
 import org.apache.activemq.broker.util.DefaultAuditLog;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -42,7 +43,7 @@ public class AnnotatedMBean extends StandardMBean {
   private static final Log LOG = LogFactory.getLog("org.apache.activemq.audit");
 
   private static boolean audit;
-  private static AuditLog auditLog;
+  private static AuditLogService auditLog;
 
   static {
     Class<?>[] p = { byte.class, short.class, int.class, long.class, float.class, double.class, char.class, boolean.class, };
@@ -50,7 +51,9 @@ public class AnnotatedMBean extends StandardMBean {
       primitives.put(c.getName(), c);
     }
     audit = "true".equalsIgnoreCase(System.getProperty("org.apache.activemq.audit"));
-    auditLog = DefaultAuditLog.getAuditLog();
+    if (audit) {
+        auditLog = new AuditLogService();
+    }
   }
   
   @SuppressWarnings("unchecked")

activemq-core/src/main/java/org/apache/activemq/broker/util/AuditLogService.java

@@ -0,0 +1,42 @@
+/**
+ * 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.activemq.broker.util;
+
+import java.util.ArrayList;
+import java.util.ServiceLoader;
+
+public class AuditLogService {
+
+    private ArrayList<AuditLog> auditLogs = new ArrayList<AuditLog>();
+
+    public AuditLogService() {
+        ServiceLoader<AuditLog> logs = ServiceLoader.load(AuditLog.class);
+        for (AuditLog log : logs) {
+            auditLogs.add(log);
+        }
+        // add default audit log if non was found
+        if (auditLogs.size() == 0) {
+            auditLogs.add(new DefaultAuditLog());
+        }
+    }
+
+    public void log(String message) {
+        for (AuditLog log : auditLogs) {
+            log.log(message);
+        }
+    }
+}

activemq-core/src/main/java/org/apache/activemq/broker/util/DefaultAuditLog.java

@@ -23,18 +23,6 @@ public class DefaultAuditLog implements AuditLog {
 
     private static final Log LOG = LogFactory.getLog("org.apache.activemq.audit");
 
-    public static AuditLog getAuditLog() {
-        String auditLogClass = System.getProperty("org.apache.activemq.audit.class", "org.apache.activemq.broker.util.DefaultAuditLog");
-        AuditLog log;
-        try {
-            log = (AuditLog) Class.forName(auditLogClass).newInstance();
-        } catch (Exception e) {
-            LOG.warn("Cannot instantiate audit log class '" + auditLogClass + "', using default audit log", e);
-            log = new DefaultAuditLog();
-        }
-        return log;
-    }
-
     public void log(String message) {
          LOG.info(message);
     }

activemq-web/src/main/java/org/apache/activemq/web/AuditFilter.java

@@ -17,6 +17,7 @@
 package org.apache.activemq.web;
 
 import org.apache.activemq.broker.util.AuditLog;
+import org.apache.activemq.broker.util.AuditLogService;
 import org.apache.activemq.broker.util.DefaultAuditLog;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -31,11 +32,11 @@ public class AuditFilter implements Filter {
     private static final Log LOG = LogFactory.getLog("org.apache.activemq.audit");
 
     private boolean audit;
-    private AuditLog auditLog;
+    private AuditLogService auditLog;
 
     public void init(FilterConfig filterConfig) throws ServletException {
         audit = "true".equalsIgnoreCase(System.getProperty("org.apache.activemq.audit"));
-        auditLog = DefaultAuditLog.getAuditLog();
+        auditLog = new AuditLogService();
     }
 
     public void destroy() {