org.slf4j.helpers.BasicMDCAdapter Maven / Gradle / Ivy
/**
* Copyright (c) 2004-2011 QOS.ch
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
package org.slf4j.helpers;
import org.slf4j.spi.MDCAdapter;
import java.util.*;
import java.util.Map;
/**
* Basic MDC implementation, which can be used with logging systems that lack
* out-of-the-box MDC support.
*
* This code was initially inspired by logback's LogbackMDCAdapter. However,
* LogbackMDCAdapter has evolved and is now considerably more sophisticated.
*
* @author Ceki Gulcu
* @author Maarten Bosteels
*
* @since 1.5.0
*/
public class BasicMDCAdapter implements MDCAdapter {
private InheritableThreadLocal inheritableThreadLocal = new InheritableThreadLocal();
static boolean isJDK14() {
try {
String javaVersion = System.getProperty("java.version");
return javaVersion.startsWith("1.4");
} catch(SecurityException se) {
// punt and assume JDK 1.5 or later
return false;
}
}
static boolean IS_JDK14 = isJDK14();
/**
* Put a context value (the val parameter) as identified with
* the key parameter into the current thread's context map.
* Note that contrary to log4j, the val parameter can be null.
*
*
* If the current thread does not have a context map it is created as a side
* effect of this call.
*
* @throws IllegalArgumentException
* in case the "key" parameter is null
*/
public void put(String key, String val) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null");
}
Map map = (Map) inheritableThreadLocal.get();
if (map == null) {
map = Collections.synchronizedMap(new HashMap());
inheritableThreadLocal.set(map);
}
map.put(key, val);
}
/**
* Get the context identified by the key parameter.
*/
public String get(String key) {
Map Map = (Map) inheritableThreadLocal.get();
if ((Map != null) && (key != null)) {
return (String) Map.get(key);
} else {
return null;
}
}
/**
* Remove the the context identified by the key parameter.
*/
public void remove(String key) {
Map map = (Map) inheritableThreadLocal.get();
if (map != null) {
map.remove(key);
}
}
/**
* Clear all entries in the MDC.
*/
public void clear() {
Map map = (Map) inheritableThreadLocal.get();
if (map != null) {
map.clear();
// the InheritableThreadLocal.remove method was introduced in JDK 1.5
// Thus, invoking clear() on previous JDK 1.4 will fail
if(isJDK14()) {
inheritableThreadLocal.set(null);
} else {
inheritableThreadLocal.remove();
}
}
}
/**
* Returns the keys in the MDC as a {@link Set} of {@link String}s The
* returned value can be null.
*
* @return the keys in the MDC
*/
public Set getKeys() {
Map map = (Map) inheritableThreadLocal.get();
if (map != null) {
return map.keySet();
} else {
return null;
}
}
/**
* Return a copy of the current thread's context map.
* Returned value may be null.
*
*/
public Map getCopyOfContextMap() {
Map oldMap = (Map) inheritableThreadLocal.get();
if (oldMap != null) {
Map newMap = Collections.synchronizedMap(new HashMap());
synchronized (oldMap) {
newMap.putAll(oldMap);
}
return newMap;
} else {
return null;
}
}
public void setContextMap(Map contextMap) {
Map map = Collections.synchronizedMap(new HashMap(contextMap));
inheritableThreadLocal.set(map);
}
}