package org.lsst.ccs.utilities.logging;
   
   import java.util.Iterator;
   import java.util.Properties;
   import org.apache.log4j.PropertyConfigurator;
   import org.lsst.ccs.bootstrap.resources.BootstrapResourceUtils;
   
   /**
    * Utility class to provide Log4j configuration.
   * All log messages coming from underlying libraries will be redirected
   * to the org.lsst.ccs.utilities.logging.JULAppender
   * so that they are logged in CCS framework.
   *
   * @author turri
   */
  public abstract class Log4JConfiguration {
  
      private static boolean isInitialized = false;
  
      public static void initialize() {
          if (!isInitialized) {
              try {
                  Properties defaultLog4JProperties = new Properties();
                  defaultLog4JProperties.setProperty("log4j.rootLogger", "info, stdout");
                  defaultLog4JProperties.setProperty("log4j.appender.julAppender", "org.lsst.ccs.utilities.logging.JULAppender");
                  defaultLog4JProperties.setProperty("log4j.appender.stdout", "org.lsst.ccs.utilities.logging.JULAppender");
                  defaultLog4JProperties.setProperty("log4j.appender.stdout.layout", "org.apache.log4j.PatternLayout");
                  defaultLog4JProperties.setProperty("log4j.appender.julAppender.layout", "org.apache.log4j.PatternLayout");
                  defaultLog4JProperties.setProperty("log4j.appender.stdout.layout.ConversionPattern", "%d{ISO8601} - %m%n");
                  defaultLog4JProperties.setProperty("log4j.logger.org.springframework.aop", "error");
                  defaultLog4JProperties.setProperty("log4j.logger.org.springframework", "error");
  
                  Properties externalProps = BootstrapResourceUtils.getBootstrapProperties("log4j");
                  Iterator iter = BootstrapResourceUtils.getAllKeysInProperties(externalProps).iterator();
                  while (iter.hasNext()) {
                      String key = (String) iter.next();
                      defaultLog4JProperties.put(key, externalProps.getProperty(key));
                  }
  
                  PropertyConfigurator.configure(defaultLog4JProperties);
                  isInitialized = true;
              } catch (Exception e) {
                  System.out.println("#### Cannot load Log4J properties file");
              }
          }
      }
  
  }