Author: mattsicker
Date: Mon May 26 03:59:52 2014
New Revision: 1597509
URL: http://svn.apache.org/r1597509
Log:
Add PluginVisitors registry class.
- Registers the PluginAttribute visitor by default.
- Will be adding other visitor implementations over time.
Added:
logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java
(with props)
Added:
logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java
URL:
http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java?rev=1597509&view=auto
==============================================================================
---
logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java
(added)
+++
logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java
Mon May 26 03:59:52 2014
@@ -0,0 +1,81 @@
+/*
+ * 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.logging.log4j.core.config.plugins.visitors;
+
+import java.lang.annotation.Annotation;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
+import org.apache.logging.log4j.status.StatusLogger;
+
+/**
+ * Registry for associating Plugin annotations with PluginVisitor
implementations.
+ */
+public final class PluginVisitors {
+
+ private static final Logger LOGGER = StatusLogger.getLogger();
+
+ // map of annotation classes to their corresponding PluginVisitor classes
+ // generics are fun!
+ private static final Map<Class<? extends Annotation>, Class<? extends
PluginVisitor<? extends Annotation>>> REGISTRY;
+
+ static {
+ // register the default PluginVisitor classes
+ REGISTRY = new ConcurrentHashMap<Class<? extends Annotation>, Class<?
extends PluginVisitor<? extends Annotation>>>();
+ registerVisitor(PluginAttribute.class, PluginAttributeVisitor.class);
+ }
+
+ private PluginVisitors() {
+ }
+
+ /**
+ * Registers a PluginVisitor class associated to a specific annotation.
+ *
+ * @param annotation the Plugin annotation to associate with.
+ * @param helper the PluginVisitor class to use for the annotation.
+ * @param <A> the Plugin annotation type.
+ */
+ public static <A extends Annotation> void registerVisitor(final Class<A>
annotation,
+ final Class<?
extends PluginVisitor<A>> helper) {
+ REGISTRY.put(annotation, helper);
+ }
+
+ /**
+ * Creates a PluginVisitor instance for the given annotation class. This
instance must be further populated with
+ * data to be useful. Such data is passed through both the setters and the
visit method.
+ *
+ * @param annotation the Plugin annotation class to find a PluginVisitor
for.
+ * @param <A> the Plugin annotation type.
+ * @return a PluginVisitor instance if one could be created, or {@code
null} otherwise.
+ */
+ @SuppressWarnings("unchecked") // we're keeping track of types, thanks
+ public static <A extends Annotation> PluginVisitor<A> findVisitor(final
Class<A> annotation) {
+ try {
+ final Class<PluginVisitor<A>> clazz = (Class<PluginVisitor<A>>)
REGISTRY.get(annotation);
+ if (clazz == null) {
+ return null;
+ }
+ return clazz.newInstance();
+ } catch (final Exception e) {
+ LOGGER.debug("No PluginVisitor found for annotation: {}.",
annotation);
+ return null;
+ }
+ }
+}
Propchange:
logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginVisitors.java
------------------------------------------------------------------------------
svn:eol-style = native
