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
018package org.apache.logging.log4j.core.config.plugins.visitors;
019
020import org.apache.logging.log4j.core.LogEvent;
021import org.apache.logging.log4j.core.config.Configuration;
022import org.apache.logging.log4j.core.config.Node;
023import org.apache.logging.log4j.core.config.plugins.PluginValue;
024import org.apache.logging.log4j.util.StringBuilders;
025import org.apache.logging.log4j.util.Strings;
026
027/**
028 * PluginVisitor implementation for {@link PluginValue}.
029 */
030public class PluginValueVisitor extends AbstractPluginVisitor<PluginValue> {
031    public PluginValueVisitor() {
032        super(PluginValue.class);
033    }
034
035    @Override
036    public Object visit(final Configuration configuration, final Node node, final LogEvent event,
037            final StringBuilder log) {
038        final String name = this.annotation.value();
039        final String elementValue = node.getValue();
040        final String attributeValue = node.getAttributes().get("value");
041        String rawValue = null; // if neither is specified, return null (LOG4J2-1313)
042        if (Strings.isNotEmpty(elementValue)) {
043            if (Strings.isNotEmpty(attributeValue)) {
044                LOGGER.error("Configuration contains {} with both attribute value ({}) AND element" +
045                                " value ({}). Please specify only one value. Using the element value.",
046                        node.getName(), attributeValue, elementValue);
047            }
048            rawValue = elementValue;
049        } else {
050            rawValue = removeAttributeValue(node.getAttributes(), "value");
051        }
052        final String value = this.substitutor.replace(event, rawValue);
053        StringBuilders.appendKeyDqValue(log, name, value);
054        return value;
055    }
056}