Log.java

package org.ocpsoft.rewrite.config;

import java.util.Set;

import org.ocpsoft.logging.Logger;
import org.ocpsoft.logging.Logger.Level;
import org.ocpsoft.rewrite.context.EvaluationContext;
import org.ocpsoft.rewrite.event.Rewrite;
import org.ocpsoft.rewrite.param.ParameterStore;
import org.ocpsoft.rewrite.param.Parameterized;
import org.ocpsoft.rewrite.param.ParameterizedPattern;
import org.ocpsoft.rewrite.param.RegexParameterizedPatternBuilder;

/**
 * An {@link Operation} responsible for logging a message.
 * 
 * @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
 */
public class Log extends DefaultOperationBuilder implements Parameterized
{
   private static final Logger log = Logger.getLogger(Log.class);

   private Level level;
   private RegexParameterizedPatternBuilder messageBuilder;

   private Log(Level level, String message)
   {
      this.level = level;
      this.messageBuilder = new RegexParameterizedPatternBuilder(message);
   }

   /**
    * Log a message at the given {@link Level}.
    * <p>
    * The message may be parameterized:
    * <p>
    * For example, assuming a given {@link Condition} has been configured to use a parameter "p"}:
    * <p>
    * <code>
    *    Path.matches("/{p}")
    * </code>
    * <p>
    * The parameter "p" may be referenced in the log message:
    * <p>
    * <code>
    *    Log.message(Level.INFO, "Client requested path: {p}")
    * </code>
    * <p>
    * 
    * @param level the log {@link Level} to which the message be written
    * @param message {@link ParameterizedPattern} to be written to the log.
    * 
    * @see {@link ConfigurationRuleParameterBuilder#where(String)}
    */
   public static Log message(Level level, String message)
   {
      return new Log(level, message);
   }

   @Override
   public void perform(Rewrite event, EvaluationContext context)
   {
      String message = messageBuilder.build(event, context);

      switch (level)
      {
      case TRACE:
         if (log.isTraceEnabled())
            log.trace(message);
         break;

      case DEBUG:
         if (log.isDebugEnabled())
            log.debug(message);
         break;

      case INFO:
         if (log.isInfoEnabled())
            log.info(message);
         break;

      case WARN:
         if (log.isWarnEnabled())
            log.warn(message);
         break;

      case ERROR:
         if (log.isErrorEnabled())
            log.error(message);
         break;

      default:
         break;
      }
   }

   @Override
   public Set<String> getRequiredParameterNames()
   {
      return messageBuilder.getRequiredParameterNames();
   }

   @Override
   public void setParameterStore(ParameterStore store)
   {
      messageBuilder.setParameterStore(store);
   }

   @Override
   public String toString()
   {
      return "Log.message(Level." + level.name() + ", \"" + messageBuilder.getPattern() + "\")";
   }

}