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 */
017package org.apache.logging.log4j.core.lookup;
018
019
020import org.apache.logging.log4j.LogManager;
021import org.apache.logging.log4j.core.LogEvent;
022import org.apache.logging.log4j.core.LoggerContext;
023import org.apache.logging.log4j.core.config.plugins.Plugin;
024import org.apache.logging.log4j.core.impl.ContextAnchor;
025
026import javax.servlet.ServletContext;
027
028
029@Plugin(name = "web", category = "Lookup")
030public class WebLookup implements StrLookup {
031    private static final String ATTR_PREFIX = "attr.";
032    private static final String INIT_PARAM_PREFIX = "initParam.";
033
034    protected ServletContext getServletContext() {
035        LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get();
036        if (lc == null) {
037            lc = (LoggerContext) LogManager.getContext(false);
038        }
039        if (lc != null) {
040            Object obj = lc.getExternalContext();
041            return obj != null && obj instanceof ServletContext ? (ServletContext) obj : null;
042        }
043        return null;
044    }
045
046    @Override
047    public String lookup(String key) {
048        ServletContext ctx = getServletContext();
049        if (ctx == null) {
050            return null;
051        }
052
053        if (key.startsWith(ATTR_PREFIX)) {
054            String attrName = key.substring(ATTR_PREFIX.length());
055            Object attrValue = ctx.getAttribute(attrName);
056            return attrValue == null ? null : attrValue.toString();
057        }
058
059        if (key.startsWith(INIT_PARAM_PREFIX)) {
060            String paramName = key.substring(INIT_PARAM_PREFIX.length());
061            return ctx.getInitParameter(paramName);
062        }
063
064        if ("rootDir".equals(key)) {
065            String root = ctx.getRealPath("/");
066            if (root == null) {
067                String msg = "failed to resolve web:rootDir -- " +
068                        "servlet container unable to translate virtual path " +
069                        " to real path (probably not deployed as exploded";
070                throw new RuntimeException(msg);
071
072            }
073            return root;
074        }
075
076        if ("contextPath".equals(key)) {
077            return ctx.getContextPath();
078        }
079
080        if ("servletContextName".equals(key)) {
081            return ctx.getServletContextName();
082        }
083
084        if ("serverInfo".equals(key)) {
085            return ctx.getServerInfo();
086        }
087
088        if ("effectiveMajorVersion".equals(key)) {
089            return String.valueOf(ctx.getEffectiveMajorVersion());
090        }
091
092        if ("effectiveMinorVersion".equals(key)) {
093            return String.valueOf(ctx.getEffectiveMinorVersion());
094        }
095
096        if ("majorVersion".equals(key)) {
097            return String.valueOf(ctx.getMajorVersion());
098        }
099
100        if ("minorVersion".equals(key)) {
101            return String.valueOf(ctx.getMinorVersion());
102        }
103
104        if (ctx.getAttribute(key) != null) {
105            return ctx.getAttribute(key).toString();
106        }
107
108        if (ctx.getInitParameter(key) != null) {
109            return ctx.getInitParameter(key);
110        }
111
112        ctx.log(getClass().getName() + " unable to resolve key '" + key + "'");
113        return null;
114    }
115
116    @Override
117    public String lookup(LogEvent event, String key) {
118        return lookup(key);
119    }
120}