StaticLoggerBinder.java

/*******************************************************************************
 * ALMA - Atacama Large Millimeter Array
 * Copyright (c) ESO - European Southern Observatory, 2011
 * (in the framework of the ALMA collaboration).
 * All rights reserved.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 *******************************************************************************/

package org.slf4j.impl;

import org.slf4j.ILoggerFactory;
import org.slf4j.LoggerFactory;
import org.slf4j.spi.LoggerFactoryBinder;

/**
 * The binding of {@link LoggerFactory} class with an actual instance of 
 * {@link ILoggerFactory} is performed using information returned by this class. 
 * <p>
 * The code is copied into ACS from the slf4j 1.5.8 sources, 
 * and modified to return {@link ACSLoggerFactory} instead of slf4j's JDK Logger factory.
 * The design of slf4j requires this StaticLoggerBinder class to be implemented in
 * package org.slf4j.impl so that slf4j will simply load it, without looking 
 * at any properties or doing class loader tricks. See http://www.slf4j.org/manual.html.
 * 
 * @author Ceki Gülcü
 */
public class StaticLoggerBinder implements LoggerFactoryBinder {

  /**
   * The unique instance of this class.
   * 
   */
  private static final StaticLoggerBinder SINGLETON = new StaticLoggerBinder();
  
  /**
   * Return the singleton of this class.
   * 
   * @return the StaticLoggerBinder singleton
   */
  public static final StaticLoggerBinder getSingleton() {
    return SINGLETON;
  }

  
  /**
   * Declare the version of the SLF4J API this implementation is compiled against. 
   * The value of this field is usually modified with each release. 
   */
  // to avoid constant folding by the compiler, this field must *not* be final
  public static String REQUESTED_API_VERSION = "1.6.99";  // !final

  
  private static final String loggerFactoryClassStr = org.slf4j.impl.ACSLoggerFactory.class.getName();

  /** The ILoggerFactory instance returned by the {@link #getLoggerFactory} method
   * should always be the same object
   */
  private final ILoggerFactory loggerFactory;
  
  private StaticLoggerBinder() {
//  Note: JCL gets substituted at build time by an appropriate Ant task
    loggerFactory = new org.slf4j.impl.ACSLoggerFactory();
  }
  
  public ILoggerFactory getLoggerFactory() {
    return loggerFactory;
  }
  
  public String getLoggerFactoryClassStr() {
    return loggerFactoryClassStr;
  }   
}