001    /*
002     * Copyright 2004 Stephen J. McConnell.
003     *
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.logging;
020    
021    /**
022     * Logger is a interface through which different logging solutions
023     * can be provided.  Typical examples of logging implementations include 
024     * java.util.logging.Logger or Ant's Project.log() function.  
025     *
026     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
027     * @version 1.0.0
028     */
029    public interface Logger
030    {
031       /**
032        * Return TRUE is debug level logging is enabled.
033        * @return the enabled state of debug logging
034        */
035        boolean isDebugEnabled();
036    
037       /**
038        * Return TRUE is trace level logging is enabled.
039        * @return the enabled state of trace logging
040        */
041        boolean isTraceEnabled();
042    
043       /**
044        * Return TRUE is info level logging is enabled.
045        * @return the enabled state of info logging
046        */
047        boolean isInfoEnabled();
048    
049       /**
050        * Return TRUE is error level logging is enabled.
051        * @return the enabled state of error logging
052        */
053        boolean isErrorEnabled();
054    
055       /**
056        * Return TRUE is error warning logging is enabled.
057        * @return the enabled state of warning logging
058        */
059        boolean isWarnEnabled();
060    
061       /**
062        * Record a debug level message.
063        * @param message the debug message to record
064        */
065        void debug( String message );
066    
067       /**
068        * Record a trace level message.
069        * @param message the trace message to record
070        */
071        void trace( String message );
072    
073       /**
074        * Record a informative message.
075        * @param message the info message to record
076        */
077        void info( String message );
078    
079       /**
080        * Record a warning message.
081        * @param message the warning message to record
082        */
083        void warn( String message );
084    
085       /**
086        * Record a warning message.
087        * @param message the warning message to record
088        * @param cause the causal exception
089        */
090        void warn( String message, Throwable cause );
091    
092       /**
093        * Record a error level message.
094        * @param message the error message to record
095        */
096        void error( String message );
097    
098       /**
099        * Record a error level message.
100        * @param message the error message to record
101        * @param cause the causal exception
102        */
103        void error( String message, Throwable cause );
104    
105       /**
106        * Return a child logger relative to the current logger.
107        * @param category the relative category name
108        * @return the child logging channel
109        */
110        Logger getChildLogger( String category );
111    }
112    
113