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