CentralSlf4jProvider.java

/*
** Module   : CentralSlf4jProvider.java
** Abstract : Implementation of slf4j provider.
**
** Copyright (c) 2024, Golden Code Development Corporation.
**
** -#- -I- --Date-- ----------------------------Description-----------------------------
** 001 GBB 20240422 Initial setup
** 002 TJD 20240423 Allow blocking of CentralSlf4jProvider with disableCentralSlf4jProvider 
**                  system property
** 003 GBB 20240709 Fixing the javadoc of the constructor.
** 004 GBB 20240729 Disable FWD slf4j impl with -DenableSlf4jApi=true jvm arg.
*/
/*
 ** This program is free software: you can redistribute it and/or modify
 ** it under the terms of the GNU Affero General Public License as
 ** published by the Free Software Foundation, either version 3 of the
 ** License, or (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU Affero General Public License for more details.
 **
 ** You may find a copy of the GNU Affero GPL version 3 at the following
 ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
 **
 ** Additional terms under GNU Affero GPL version 3 section 7:
 **
 **   Under Section 7 of the GNU Affero GPL version 3, the following additional
 **   terms apply to the works covered under the License.  These additional terms
 **   are non-permissive additional terms allowed under Section 7 of the GNU
 **   Affero GPL version 3 and may not be removed by you.
 **
 **   0. Attribution Requirement.
 **
 **     You must preserve all legal notices or author attributions in the covered
 **     work or Appropriate Legal Notices displayed by works containing the covered
 **     work.  You may not remove from the covered work any author or developer
 **     credit already included within the covered work.
 **
 **   1. No License To Use Trademarks.
 **
 **     This license does not grant any license or rights to use the trademarks
 **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
 **     of Golden Code Development Corporation. You are not authorized to use the
 **     name Golden Code, FWD, or the names of any author or contributor, for
 **     publicity purposes without written authorization.
 **
 **   2. No Misrepresentation of Affiliation.
 **
 **     You may not represent yourself as Golden Code Development Corporation or FWD.
 **
 **     You may not represent yourself for publicity purposes as associated with
 **     Golden Code Development Corporation, FWD, or any author or contributor to
 **     the covered work, without written authorization.
 **
 **   3. No Misrepresentation of Source or Origin.
 **
 **     You may not represent the covered work as solely your work.  All modified
 **     versions of the covered work must be marked in a reasonable way to make it
 **     clear that the modified work is not originating from Golden Code Development
 **     Corporation or FWD.  All modified versions must contain the notices of
 **     attribution required in this license.
 */
package com.goldencode.p2j.util.logging;

import org.slf4j.*;
import org.slf4j.helpers.*;
import org.slf4j.spi.*;

/** Implementation of slf4j provider. */
public class CentralSlf4jProvider
implements SLF4JServiceProvider
{
   /** The custom logger factory. */
   private static final CentralSlf4jLoggerFactory loggerFactory = new CentralSlf4jLoggerFactory();

   /** The default base marker factory. */
   private static IMarkerFactory markerFactory = new BasicMarkerFactory();

   /** The default base mdc adapter. */
   private static MDCAdapter mdcAdapter = new BasicMDCAdapter();
   
   /** 
    * The lowest compatible api version.
    * <p>
    * To avoid constant folding by the compiler, this field must *not* be final
    */
   public static String REQUESTED_API_VERSION = "2.0.0"; // !final
   
   /**
    * Public constructor, allows preventing instantiation of the provider.
    */
   public CentralSlf4jProvider()
   {
      if (Boolean.parseBoolean(System.getProperty("disableCentralSlf4jProvider", "false")) ||
         Boolean.parseBoolean(System.getProperty(CentralLogger.JVM_ARG_ENABLE_SLF4j_API, "false")))
      {
         // prevent this provider from being instantiated
         throw new RuntimeException("JVM arg `disableCentralSlf4jProvider` or `" + 
                                       CentralLogger.JVM_ARG_ENABLE_SLF4j_API + 
                                       "` prevents FWD's slf4j implementation to get started.");
      }
   }

   /**
    * Returns the logger factory instance.
    *
    * @return   See above.
    */
   @Override
   public ILoggerFactory getLoggerFactory()
   {
      return loggerFactory;
   }

   /**
    * Return the marker factory instance.
    *
    * @return   See above.
    */
   @Override
   public IMarkerFactory getMarkerFactory()
   {
      return markerFactory;
   }

   /**
    * Returns the mdc adapter instance.
    *
    * @return   See above.
    */
   @Override
   public MDCAdapter getMDCAdapter()
   {
      return mdcAdapter;
   }

   /**
    * Returns the lowest compatible api version.
    *
    * @return   See above.
    */
   @Override
   public String getRequestedApiVersion()
   {
      return REQUESTED_API_VERSION;
   }

   /**
    * Initialization of all factories and adapters needed.
    */
   @Override
   public void initialize()
   {
      // all fields are static final
   }
}