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.core.selector; 018 019 import java.net.URI; 020 import java.util.ArrayList; 021 import java.util.Collections; 022 import java.util.List; 023 import java.util.Map; 024 import java.util.concurrent.ConcurrentHashMap; 025 import java.util.concurrent.ConcurrentMap; 026 027 import javax.naming.Context; 028 import javax.naming.InitialContext; 029 import javax.naming.NameNotFoundException; 030 import javax.naming.NamingException; 031 032 import org.apache.logging.log4j.core.LoggerContext; 033 import org.apache.logging.log4j.core.impl.ContextAnchor; 034 import org.apache.logging.log4j.core.util.Constants; 035 import org.apache.logging.log4j.core.util.JndiCloser; 036 import org.apache.logging.log4j.status.StatusLogger; 037 038 /** 039 * This class can be used to define a 040 * custom logger repository. It makes use of the fact that in J2EE 041 * environments, each web-application is guaranteed to have its own JNDI 042 * context relative to the <code>java:comp/env</code> context. In EJBs, each 043 * enterprise bean (albeit not each application) has its own context relative 044 * to the <code>java:comp/env</code> context. An <code>env-entry</code> in a 045 * deployment descriptor provides the information to the JNDI context. Once the 046 * <code>env-entry</code> is set, a repository selector can query the JNDI 047 * application context to look up the value of the entry. The logging context of 048 * the web-application will depend on the value the env-entry. The JNDI context 049 * which is looked up by this class is 050 * <code>java:comp/env/log4j/context-name</code>. 051 * 052 * <p>Here is an example of an <code>env-entry<code>: 053 * <blockquote> 054 * <pre> 055 * <env-entry> 056 * <description>JNDI logging context name for this app</description> 057 * <env-entry-name>log4j/context-name</env-entry-name> 058 * <env-entry-value>aDistinctiveLoggingContextName</env-entry-value> 059 * <env-entry-type>java.lang.String</env-entry-type> 060 * </env-entry> 061 * </pre> 062 * </blockquote> 063 * </p> 064 * 065 * <p><em>If multiple applications use the same logging context name, then they 066 * will share the same logging context.</em> 067 * </p> 068 * 069 *<p>You can also specify the URL for this context's configuration resource. 070 * This repository selector (ContextJNDISelector) will use this resource 071 * to automatically configure the log4j repository. 072 *</p> 073 ** <blockquote> 074 * <pre> 075 * <env-entry> 076 * <description>URL for configuring log4j context</description> 077 * <env-entry-name>log4j/configuration-resource</env-entry-name> 078 * <env-entry-value>urlOfConfigrationResource</env-entry-value> 079 * <env-entry-type>java.lang.String</env-entry-type> 080 * </env-entry> 081 * </pre> 082 * </blockquote> 083 * 084 * <p>It usually good practice for configuration resources of distinct 085 * applications to have distinct names. However, if this is not possible 086 * Naming 087 * </p> 088 * 089 */ 090 public class JndiContextSelector implements NamedContextSelector { 091 092 private static final LoggerContext CONTEXT = new LoggerContext("Default"); 093 094 private static final ConcurrentMap<String, LoggerContext> CONTEXT_MAP = 095 new ConcurrentHashMap<String, LoggerContext>(); 096 097 private static final StatusLogger LOGGER = StatusLogger.getLogger(); 098 099 @Override 100 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final boolean currentContext) { 101 return getContext(fqcn, loader, currentContext, null); 102 } 103 104 @Override 105 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final boolean currentContext, 106 final URI configLocation) { 107 108 final LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get(); 109 if (lc != null) { 110 return lc; 111 } 112 113 String loggingContextName = null; 114 115 Context ctx = null; 116 try { 117 ctx = new InitialContext(); 118 loggingContextName = (String) lookup(ctx, Constants.JNDI_CONTEXT_NAME); 119 } catch (final NamingException ne) { 120 LOGGER.error("Unable to lookup " + Constants.JNDI_CONTEXT_NAME, ne); 121 } finally { 122 JndiCloser.closeSilently(ctx); 123 } 124 125 return loggingContextName == null ? CONTEXT : locateContext(loggingContextName, null, configLocation); 126 } 127 128 @Override 129 public LoggerContext locateContext(final String name, final Object externalContext, final URI configLocation) { 130 if (name == null) { 131 LOGGER.error("A context name is required to locate a LoggerContext"); 132 return null; 133 } 134 if (!CONTEXT_MAP.containsKey(name)) { 135 final LoggerContext ctx = new LoggerContext(name, externalContext, configLocation); 136 CONTEXT_MAP.putIfAbsent(name, ctx); 137 } 138 return CONTEXT_MAP.get(name); 139 } 140 141 @Override 142 public void removeContext(final LoggerContext context) { 143 144 for (final Map.Entry<String, LoggerContext> entry : CONTEXT_MAP.entrySet()) { 145 if (entry.getValue().equals(context)) { 146 CONTEXT_MAP.remove(entry.getKey()); 147 } 148 } 149 } 150 151 @Override 152 public LoggerContext removeContext(final String name) { 153 return CONTEXT_MAP.remove(name); 154 } 155 156 @Override 157 public List<LoggerContext> getLoggerContexts() { 158 final List<LoggerContext> list = new ArrayList<LoggerContext>(CONTEXT_MAP.values()); 159 return Collections.unmodifiableList(list); 160 } 161 162 163 protected static Object lookup(final Context ctx, final String name) throws NamingException { 164 if (ctx == null) { 165 return null; 166 } 167 try { 168 return ctx.lookup(name); 169 } catch (final NameNotFoundException e) { 170 LOGGER.error("Could not find name [" + name + "]."); 171 throw e; 172 } 173 } 174 }