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    package org.apache.logging.log4j.web;
018    // Please note that if you move this class, make sure to update the Interpolator class (if still applicable) or remove
019    // this comment if no longer relevant
020    
021    import javax.servlet.ServletContext;
022    
023    import org.apache.logging.log4j.core.LogEvent;
024    import org.apache.logging.log4j.core.config.plugins.Plugin;
025    import org.apache.logging.log4j.core.lookup.AbstractLookup;
026    import org.apache.logging.log4j.util.Strings;
027    
028    @Plugin(name = "web", category = "Lookup")
029    public class WebLookup extends AbstractLookup {
030        private static final String ATTR_PREFIX = "attr.";
031        private static final String INIT_PARAM_PREFIX = "initParam.";
032    
033        /**
034         * @deprecated Use {@link WebLoggerContextUtils#getServletContext()}.
035         */
036        @Deprecated
037        protected ServletContext getServletContext() {
038            return WebLoggerContextUtils.getServletContext();
039        }
040    
041        @Override
042        public String lookup(final LogEvent event, final String key) {
043            final ServletContext ctx = WebLoggerContextUtils.getServletContext();
044            if (ctx == null) {
045                return null;
046            }
047    
048            if (key.startsWith(ATTR_PREFIX)) {
049                final String attrName = key.substring(ATTR_PREFIX.length());
050                final Object attrValue = ctx.getAttribute(attrName);
051                return attrValue == null ? null : attrValue.toString();
052            }
053    
054            if (key.startsWith(INIT_PARAM_PREFIX)) {
055                final String paramName = key.substring(INIT_PARAM_PREFIX.length());
056                return ctx.getInitParameter(paramName);
057            }
058    
059            if ("rootDir".equals(key)) {
060                final String root = ctx.getRealPath("/");
061                if (root == null) {
062                    final String msg = "Failed to resolve web:rootDir -- " +
063                            "servlet container unable to translate virtual path " +
064                            " to real path (probably not deployed as exploded";
065                    throw new IllegalStateException(msg);
066                }
067                return root;
068            }
069    
070            if ("contextPath".equals(key)) {
071                return ctx.getContextPath();
072            }
073    
074            if ("servletContextName".equals(key)) {
075                return ctx.getServletContextName();
076            }
077    
078            if ("serverInfo".equals(key)) {
079                return ctx.getServerInfo();
080            }
081    
082            if ("effectiveMajorVersion".equals(key)) {
083                return String.valueOf(ctx.getEffectiveMajorVersion());
084            }
085    
086            if ("effectiveMinorVersion".equals(key)) {
087                return String.valueOf(ctx.getEffectiveMinorVersion());
088            }
089    
090            if ("majorVersion".equals(key)) {
091                return String.valueOf(ctx.getMajorVersion());
092            }
093    
094            if ("minorVersion".equals(key)) {
095                return String.valueOf(ctx.getMinorVersion());
096            }
097    
098            if (ctx.getAttribute(key) != null) {
099                return ctx.getAttribute(key).toString();
100            }
101    
102            if (ctx.getInitParameter(key) != null) {
103                return ctx.getInitParameter(key);
104            }
105    
106            ctx.log(getClass().getName() + " unable to resolve key " + Strings.quote(key));
107            return null;
108        }
109    }