Log4JLogger.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.logging.impl;
import java.io.Serializable;
import org.apache.commons.logging.Log;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.Priority;
/**
* Implementation of {@link Log} that maps directly to a
* <strong>Logger</strong> for log4J version 1.2.
* <p>
* Initial configuration of the corresponding Logger instances should be done
* in the usual manner, as outlined in the Log4J documentation.
* <p>
* The reason this logger is distinct from the 1.3.0 logger is that in version 1.2
* of Log4J:
* <ul>
* <li>class Logger takes Priority parameters not Level parameters.
* <li>class Level extends Priority
* </ul>
* Log4j 1.3 is expected to change Level so it no longer extends Priority, which is
* a non-binary-compatible change. The class generated by compiling this code against
* Log4j 1.2 will therefore not run against Log4j 1.3.
*
* @deprecated Scheduled for removal since version 1.x of Log4j has reached end-of-life.
*/
@Deprecated
public class Log4JLogger implements Log, Serializable {
/** Serializable version identifier. */
private static final long serialVersionUID = 5160705895411730424L;
/** The fully qualified name of the Log4JLogger class. */
private static final String FQCN = Log4JLogger.class.getName();
private static final Priority traceLevel;
//
// Note that this must come after the static variable declarations
// otherwise initializer expressions associated with those variables
// will override any settings done here.
//
// Verify that Log4j is available, and that it is version 1.2.
// If an ExceptionInInitializerError is generated, then LogFactoryImpl
// will treat that as meaning that the appropriate underlying logging
// library is just not present - if discovery is in progress then
// discovery will continue.
static {
if (!Priority.class.isAssignableFrom(Level.class)) {
// nope, this is Log4j 1.3, so force an ExceptionInInitializerError
throw new InstantiationError("Log4J 1.2 not available");
}
// Releases of Log4j 1.2 >= 1.2.12 have Priority.TRACE available, earlier
// versions do not. If TRACE is not available, then we have to map
// calls to Log.trace(...) onto the DEBUG level.
Priority _traceLevel;
try {
_traceLevel = (Priority) Level.class.getDeclaredField("TRACE").get(null);
} catch (final Exception ex) {
// ok, trace not available
_traceLevel = Level.DEBUG;
}
traceLevel = _traceLevel;
}
/** Log to this logger */
private transient volatile Logger logger;
/** Logger name */
private final String name;
/**
* Constructs a new instance.
*/
public Log4JLogger() {
name = null;
}
/**
* For use with a Log4j factory.
*
* @param logger Logger.
*/
public Log4JLogger(final Logger logger) {
if (logger == null) {
throw new IllegalArgumentException(
"Warning - null logger in constructor; possible Log4j misconfiguration.");
}
this.name = logger.getName();
this.logger = logger;
}
/**
* Base constructor.
*
* @param name name.
*/
public Log4JLogger(final String name) {
this.name = name;
this.logger = getLogger();
}
/**
* Logs a message with {@code org.apache.log4j.Priority.DEBUG}.
*
* @param message to log
* @see org.apache.commons.logging.Log#debug(Object)
*/
@Override
public void debug(final Object message) {
getLogger().log(FQCN, Level.DEBUG, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.DEBUG}.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#debug(Object, Throwable)
*/
@Override
public void debug(final Object message, final Throwable t) {
getLogger().log(FQCN, Level.DEBUG, message, t);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.ERROR}.
*
* @param message to log
* @see org.apache.commons.logging.Log#error(Object)
*/
@Override
public void error(final Object message) {
getLogger().log(FQCN, Level.ERROR, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.ERROR}.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#error(Object, Throwable)
*/
@Override
public void error(final Object message, final Throwable t) {
getLogger().log(FQCN, Level.ERROR, message, t);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.FATAL}.
*
* @param message to log
* @see org.apache.commons.logging.Log#fatal(Object)
*/
@Override
public void fatal(final Object message) {
getLogger().log(FQCN, Level.FATAL, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.FATAL}.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#fatal(Object, Throwable)
*/
@Override
public void fatal(final Object message, final Throwable t) {
getLogger().log(FQCN, Level.FATAL, message, t);
}
/**
* Gets the native Logger instance we are using.
*
* @return the native Logger instance we are using.
*/
public Logger getLogger() {
Logger result = logger;
if (result == null) {
synchronized(this) {
result = logger;
if (result == null) {
logger = result = Logger.getLogger(name);
}
}
}
return result;
}
/**
* Logs a message with {@code org.apache.log4j.Priority.INFO}.
*
* @param message to log
* @see org.apache.commons.logging.Log#info(Object)
*/
@Override
public void info(final Object message) {
getLogger().log(FQCN, Level.INFO, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.INFO}.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#info(Object, Throwable)
*/
@Override
public void info(final Object message, final Throwable t) {
getLogger().log(FQCN, Level.INFO, message, t);
}
/**
* Tests whether the Log4j Logger used is enabled for {@code DEBUG} priority.
*/
@Override
public boolean isDebugEnabled() {
return getLogger().isDebugEnabled();
}
/**
* Tests whether the Log4j Logger used is enabled for {@code ERROR} priority.
*/
@Override
public boolean isErrorEnabled() {
return getLogger().isEnabledFor(Level.ERROR);
}
/**
* Tests whether the Log4j Logger used is enabled for {@code FATAL} priority.
*/
@Override
public boolean isFatalEnabled() {
return getLogger().isEnabledFor(Level.FATAL);
}
/**
* Tests whether the Log4j Logger used is enabled for {@code INFO} priority.
*/
@Override
public boolean isInfoEnabled() {
return getLogger().isInfoEnabled();
}
/**
* Tests whether the Log4j Logger used is enabled for {@code TRACE} priority.
* When using a Log4j version that does not support the TRACE level, this call
* will report whether {@code DEBUG} is enabled or not.
*/
@Override
public boolean isTraceEnabled() {
return getLogger().isEnabledFor(traceLevel);
}
/**
* Tests whether the Log4j Logger used is enabled for {@code WARN} priority.
*/
@Override
public boolean isWarnEnabled() {
return getLogger().isEnabledFor(Level.WARN);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.TRACE}.
* When using a Log4j version that does not support the {@code TRACE}
* level, the message will be logged at the {@code DEBUG} level.
*
* @param message to log
* @see org.apache.commons.logging.Log#trace(Object)
*/
@Override
public void trace(final Object message) {
getLogger().log(FQCN, traceLevel, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.TRACE}.
* When using a Log4j version that does not support the {@code TRACE}
* level, the message will be logged at the {@code DEBUG} level.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#trace(Object, Throwable)
*/
@Override
public void trace(final Object message, final Throwable t) {
getLogger().log(FQCN, traceLevel, message, t);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.WARN}.
*
* @param message to log
* @see org.apache.commons.logging.Log#warn(Object)
*/
@Override
public void warn(final Object message) {
getLogger().log(FQCN, Level.WARN, message, null);
}
/**
* Logs a message with {@code org.apache.log4j.Priority.WARN}.
*
* @param message to log
* @param t log this cause
* @see org.apache.commons.logging.Log#warn(Object, Throwable)
*/
@Override
public void warn(final Object message, final Throwable t) {
getLogger().log(FQCN, Level.WARN, message, t);
}
}