001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements. See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License. You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.logging.log4j.core.config.plugins.visitors;
019    
020    import org.apache.logging.log4j.core.LogEvent;
021    import org.apache.logging.log4j.core.config.Configuration;
022    import org.apache.logging.log4j.core.config.Node;
023    import org.apache.logging.log4j.core.config.plugins.PluginNode;
024    
025    /**
026     * PluginVisitor implementation for {@link PluginNode}
027     */
028    public class PluginNodeVisitor extends AbstractPluginVisitor<PluginNode> {
029        public PluginNodeVisitor() {
030            super(PluginNode.class);
031        }
032    
033        @Override
034        public Object visit(final Configuration configuration, final Node node, final LogEvent event,
035                            final StringBuilder log) {
036            if (this.conversionType.isInstance(node)) {
037                log.append("Node=").append(node.getName());
038                return node;
039            }
040            LOGGER.warn("Variable annotated with @PluginNode is not compatible with the type {}.", node.getClass());
041            return null;
042        }
043    }