log4j-api/src/main/java/org/apache/logging/log4j/Logger.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.logging.log4j;

import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.MessageFactory;
import org.apache.logging.log4j.spi.LoggerStream;

/**
 * This is the central interface in the log4j package. Most logging operations, except configuration, are done through
 * this interface.
 */
public interface Logger {

    /**
     * Logs an exception or error that has been caught.
     * 
     * @param level The logging Level.
     * @param t The Throwable.
     */
    void catching(Level level, Throwable t);

    /**
     * Logs an exception or error that has been caught.
     * 
     * @param t The Throwable.
     */
    void catching(Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void debug(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void debug(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#DEBUG DEBUG} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void debug(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#DEBUG DEBUG} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void debug(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#DEBUG DEBUG} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void debug(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void debug(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#DEBUG DEBUG} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void debug(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param msg the message string to be logged
     */
    void debug(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void debug(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#DEBUG DEBUG} level.
     * 
     * @param message the message object to log.
     */
    void debug(Object message);

    /**
     * Logs a message at the {@link Level#DEBUG DEBUG} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void debug(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#DEBUG DEBUG} level.
     * 
     * @param message the message object to log.
     */
    void debug(String message);

    /**
     * Logs a message with parameters at the {@link Level#DEBUG DEBUG} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void debug(String message, Object... params);

    /**
     * Logs a message at the {@link Level#DEBUG DEBUG} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void debug(String message, Throwable t);

    /**
     * Logs entry to a method.
     */
    void entry();

    /**
     * Logs entry to a method.
     * 
     * @param params The parameters to the method.
     * @doubt Use of varargs results in array creation which can be a substantial portion of no-op case. LogMF/LogSF
     *        provides several overrides to avoid vararg except in edge cases. (RG) LogMF and LogSF implement these in
     *        LogXF which calls logger.callAppenders. callAppenders is part of the implementation and cannot be used by
     *        the API. Adding more methods here and in AbstractLogger is sufficient.
     */
    void entry(Object... params);

    /**
     * Logs a message with the specific Marker at the {@link Level#ERROR ERROR} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void error(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#ERROR ERROR} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void error(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#ERROR ERROR} level.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message object to log.
     */
    void error(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#ERROR ERROR} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void error(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#ERROR ERROR} level.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message object to log.
     */
    void error(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#ERROR ERROR} level.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) I assume you meant error, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature. Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void error(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#ERROR ERROR} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void error(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#ERROR ERROR} level.
     * 
     * @param msg the message string to be logged
     */
    void error(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#ERROR ERROR} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void error(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#ERROR ERROR} level.
     * 
     * @param message the message object to log.
     */
    void error(Object message);

    /**
     * Logs a message at the {@link Level#ERROR ERROR} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void error(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#ERROR ERROR} level.
     * 
     * @param message the message object to log.
     */
    void error(String message);

    /**
     * Logs a message with parameters at the {@link Level#ERROR ERROR} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) I assume you meant error, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature. Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void error(String message, Object... params);

    /**
     * Logs a message at the {@link Level#ERROR ERROR} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void error(String message, Throwable t);

    /**
     * Logs exit from a method.
     */
    void exit();

    /**
     * Logs exiting from a method with the result. This may be coded as <br />
     * return logger.exit(myResult);
     * 
     * @param <R> The type of the parameter and object being returned.
     * @param result The result being returned from the method call.
     * @return the result.
     */
    <R> R exit(R result);

    /**
     * Logs a message with the specific Marker at the {@link Level#FATAL FATAL} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void fatal(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#FATAL FATAL} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void fatal(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#FATAL FATAL} level.
     * 
     * @param marker The marker data specific to this log statement.
     * @param message the message object to log.
     */
    void fatal(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#FATAL FATAL} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker The marker data specific to this log statement.
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void fatal(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#FATAL FATAL} level.
     * 
     * @param marker The marker data specific to this log statement.
     * @param message the message object to log.
     */
    void fatal(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#FATAL FATAL} level.
     * 
     * @param marker The marker data specific to this log statement.
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call.(RG) I assume you meant fatal, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature. Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void fatal(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#FATAL FATAL} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker The marker data specific to this log statement.
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void fatal(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#FATAL FATAL} level.
     * 
     * @param msg the message string to be logged
     */
    void fatal(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#FATAL FATAL} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void fatal(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#FATAL FATAL} level.
     * 
     * @param message the message object to log.
     */
    void fatal(Object message);

    /**
     * Logs a message at the {@link Level#FATAL FATAL} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void fatal(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#FATAL FATAL} level.
     * 
     * @param message the message object to log.
     */
    void fatal(String message);

    /**
     * Logs a message with parameters at the {@link Level#FATAL FATAL} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call.(RG) I assume you meant fatal, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature. Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void fatal(String message, Object... params);

    /**
     * Logs a message at the {@link Level#FATAL FATAL} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void fatal(String message, Throwable t);

    /**
     * Gets the message factory used to convert message Objects and Strings into actual log Messages.
     * 
     * @return the message factory.
     */
    MessageFactory getMessageFactory();

    /**
     * Gets the logger name.
     * 
     * @return the logger name.
     */
    String getName();

    /**
     * Gets a print stream that logs lines to this logger.
     * 
     * @param level the logging level
     * @return print stream that logs printed lines to this logger.
     */
    LoggerStream getStream(Level level);

    /**
     * Gets a marked print stream that logs lines to this logger.
     * 
     * @param marker the marker data specific to this log statement
     * @param level the logging level
     * @return print stream that logs printed lines to this logger.
     */
    LoggerStream getStream(Marker marker, Level level);

    /**
     * Logs a message with the specific Marker at the {@link Level#INFO INFO} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void info(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#INFO INFO} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void info(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#INFO INFO} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void info(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#INFO INFO} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void info(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#INFO INFO} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void info(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#INFO INFO} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) It isn't possible to be misinterpreted as the previous method
     *        is for that signature. Methods should be added to avoid varargs for 1, 2 or 3 parameters.
     */
    void info(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#INFO INFO} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void info(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#INFO INFO} level.
     * 
     * @param msg the message string to be logged
     */
    void info(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#INFO INFO} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void info(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#INFO INFO} level.
     * 
     * @param message the message object to log.
     */
    void info(Object message);

    /**
     * Logs a message at the {@link Level#INFO INFO} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void info(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#INFO INFO} level.
     * 
     * @param message the message object to log.
     */
    void info(String message);

    /**
     * Logs a message with parameters at the {@link Level#INFO INFO} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) It isn't possible to be misinterpreted as the previous method
     *        is for that signature. Methods should be added to avoid varargs for 1, 2 or 3 parameters.
     */
    void info(String message, Object... params);

    /**
     * Logs a message at the {@link Level#INFO INFO} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void info(String message, Throwable t);

    /**
     * Checks whether this Logger is enabled for the {@link Level#DEBUG DEBUG} Level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level DEBUG, {@code false} otherwise.
     */
    boolean isDebugEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#DEBUG DEBUG} Level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level DEBUG, {@code false} otherwise.
     */
    boolean isDebugEnabled(Marker marker);

    /**
     * Checks whether this Logger is enabled for the the given Level.
     * <p>
     * Note that passing in {@link Level#OFF OFF} always returns {@code true}.
     * </p>
     * 
     * @param level the level to check
     * @return boolean - {@code true} if this Logger is enabled for level, {@code false} otherwise.
     */
    boolean isEnabled(Level level);

    /**
     * Checks whether this logger is enabled at the specified level and an optional Marker.
     * 
     * @param level The Level to check.
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#WARN WARN}, {@code false}
     *         otherwise.
     */
    boolean isEnabled(Level level, Marker marker);

    /**
     * Checks whether this Logger is enabled for the {@link Level#ERROR ERROR} Level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#ERROR ERROR}, {@code false}
     *         otherwise.
     */
    boolean isErrorEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#ERROR ERROR} Level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#ERROR ERROR}, {@code false}
     *         otherwise.
     */
    boolean isErrorEnabled(Marker marker);

    /**
     * Checks whether this Logger is enabled for the {@link Level#FATAL FATAL} Level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#FATAL FATAL}, {@code false}
     *         otherwise.
     */
    boolean isFatalEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#FATAL FATAL} Level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#FATAL FATAL}, {@code false}
     *         otherwise.
     */
    boolean isFatalEnabled(Marker marker);

    /**
     * Checks whether this Logger is enabled for the {@link Level#INFO INFO} Level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level INFO, {@code false} otherwise.
     */
    boolean isInfoEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#INFO INFO} Level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level INFO, {@code false} otherwise.
     */
    boolean isInfoEnabled(Marker marker);

    /**
     * Checks whether this Logger is enabled for the {@link Level#TRACE TRACE} level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level TRACE, {@code false} otherwise.
     */
    boolean isTraceEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#TRACE TRACE} level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level TRACE, {@code false} otherwise.
     */
    boolean isTraceEnabled(Marker marker);

    /**
     * Checks whether this Logger is enabled for the {@link Level#WARN WARN} Level.
     * 
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#WARN WARN}, {@code false}
     *         otherwise.
     */
    boolean isWarnEnabled();

    /**
     * Checks whether this Logger is enabled for the {@link Level#WARN WARN} Level.
     * 
     * @param marker The marker data specific to this log statement.
     * @return boolean - {@code true} if this Logger is enabled for level {@link Level#WARN WARN}, {@code false}
     *         otherwise.
     */
    boolean isWarnEnabled(Marker marker);

    /**
     * Logs a message with the specific Marker at the given level.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void log(Level level, Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the given level.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void log(Level level, Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the given level.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void log(Level level, Marker marker, Object message);

    /**
     * Logs a message at the given level including the stack trace of the {@link Throwable} <code>t</code> passed as
     * parameter.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void log(Level level, Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the given level.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void log(Level level, Marker marker, String message);

    /**
     * Logs a message with parameters at the given level.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void log(Level level, Marker marker, String message, Object... params);

    /**
     * Logs a message at the given level including the stack trace of the {@link Throwable} <code>t</code> passed as
     * parameter.
     * 
     * @param level the logging level
     * @param marker the marker data specific to this log statement
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void log(Level level, Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the given level.
     * 
     * @param level the logging level
     * @param msg the message string to be logged
     */
    void log(Level level, Message msg);

    /**
     * Logs a message with the specific Marker at the given level.
     * 
     * @param level the logging level
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void log(Level level, Message msg, Throwable t);

    /**
     * Logs a message object with the given level.
     * 
     * @param level the logging level
     * @param message the message object to log.
     */
    void log(Level level, Object message);

    /**
     * Logs a message at the given level including the stack trace of the {@link Throwable} <code>t</code> passed as
     * parameter.
     * 
     * @param level the logging level
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void log(Level level, Object message, Throwable t);

    /**
     * Logs a message object with the given level.
     * 
     * @param level the logging level
     * @param message the message object to log.
     */
    void log(Level level, String message);

    /**
     * Logs a message with parameters at the given level.
     * 
     * @param level the logging level
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void log(Level level, String message, Object... params);

    /**
     * Logs a message at the given level including the stack trace of the {@link Throwable} <code>t</code> passed as
     * parameter.
     * 
     * @param level the logging level
     * @param message the message to log.
     * @param t the exception to log, including its stack trace.
     */
    void log(Level level, String message, Throwable t);

    /**
     * Logs a formatted message using the specified format string and arguments.
     * 
     * @param level The logging Level.
     * @param marker the marker data specific to this log statement.
     * @param format The format String.
     * @param params Arguments specified by the format.
     */
    void printf(Level level, Marker marker, String format, Object... params);

    /**
     * Logs a formatted message using the specified format string and arguments.
     * 
     * @param level The logging Level.
     * @param format The format String.
     * @param params Arguments specified by the format.
     */
    void printf(Level level, String format, Object... params);

    /**
     * Logs an exception or error to be thrown. This may be coded as <br />
     * throw logger.throwing(debug, myException);
     * 
     * @param <T> the Throwable type.
     * @param level The logging Level.
     * @param t The Throwable.
     * @return the Throwable.
     */
    <T extends Throwable> T throwing(Level level, T t);

    /**
     * Logs an exception or error to be thrown. This may be coded as <br />
     * throw logger.throwing(myException);
     * 
     * @param <T> the Throwable type.
     * @param t The Throwable.
     * @return the Throwable.
     */
    <T extends Throwable> T throwing(T t);

    /**
     * Logs a message with the specific Marker at the {@link Level#TRACE TRACE} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void trace(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#TRACE TRACE} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void trace(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#TRACE TRACE} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void trace(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#TRACE TRACE} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * <p/>
     * <p>
     * See {@link #debug(String)} form for more detailed information.
     * </p>
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void trace(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#TRACE TRACE} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void trace(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#TRACE TRACE} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void trace(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#TRACE TRACE} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * <p/>
     * <p>
     * See {@link #debug(String)} form for more detailed information.
     * </p>
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void trace(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#TRACE TRACE} level.
     * 
     * @param msg the message string to be logged
     */
    void trace(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#TRACE TRACE} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void trace(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#TRACE TRACE} level.
     * 
     * @param message the message object to log.
     */
    void trace(Object message);

    /**
     * Logs a message at the {@link Level#TRACE TRACE} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * <p/>
     * <p>
     * See {@link #debug(String)} form for more detailed information.
     * </p>
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void trace(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#TRACE TRACE} level.
     * 
     * @param message the message object to log.
     */
    void trace(String message);

    /**
     * Logs a message with parameters at the {@link Level#TRACE TRACE} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     */
    void trace(String message, Object... params);

    /**
     * Logs a message at the {@link Level#TRACE TRACE} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * <p/>
     * <p>
     * See {@link #debug(String)} form for more detailed information.
     * </p>
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void trace(String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#WARN WARN} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     */
    void warn(Marker marker, Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#WARN WARN} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void warn(Marker marker, Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#WARN WARN} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void warn(Marker marker, Object message);

    /**
     * Logs a message at the {@link Level#WARN WARN} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void warn(Marker marker, Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#WARN WARN} level.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     */
    void warn(Marker marker, String message);

    /**
     * Logs a message with parameters at the {@link Level#WARN WARN} level.
     * 
     * @param marker the marker data specific to this log statement.
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) I assume you meant warn, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature.Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void warn(Marker marker, String message, Object... params);

    /**
     * Logs a message at the {@link Level#WARN WARN} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param marker the marker data specific to this log statement
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void warn(Marker marker, String message, Throwable t);

    /**
     * Logs a message with the specific Marker at the {@link Level#WARN WARN} level.
     * 
     * @param msg the message string to be logged
     */
    void warn(Message msg);

    /**
     * Logs a message with the specific Marker at the {@link Level#WARN WARN} level.
     * 
     * @param msg the message string to be logged
     * @param t A Throwable or null.
     */
    void warn(Message msg, Throwable t);

    /**
     * Logs a message object with the {@link Level#WARN WARN} level.
     * 
     * @param message the message object to log.
     */
    void warn(Object message);

    /**
     * Logs a message at the {@link Level#WARN WARN} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void warn(Object message, Throwable t);

    /**
     * Logs a message object with the {@link Level#WARN WARN} level.
     * 
     * @param message the message object to log.
     */
    void warn(String message);

    /**
     * Logs a message with parameters at the {@link Level#WARN WARN} level.
     * 
     * @param message the message to log; the format depends on the message factory.
     * @param params parameters to the message.
     * @see #getMessageFactory()
     * 
     * @doubt Likely to misinterpret existing log4j client code that intended to call info(Object,Throwable). Incurs
     *        array creation expense on every call. (RG) I assume you meant warn, not info. It isn't possible to be
     *        misinterpreted as the previous method is for that signature.Methods should be added to avoid varargs for
     *        1, 2 or 3 parameters.
     */
    void warn(String message, Object... params);

    /**
     * Logs a message at the {@link Level#WARN WARN} level including the stack trace of the {@link Throwable}
     * <code>t</code> passed as parameter.
     * 
     * @param message the message object to log.
     * @param t the exception to log, including its stack trace.
     */
    void warn(String message, Throwable t);
}