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