package com.atlassian.vcache.internal.core;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import static java.util.Objects.requireNonNull;
   
   /**
    * Implementation of {@link ExternalCacheKeyGenerator} that logs at <tt>debug</tt> level the key before and after.
   *
   * @since 1.0.0
   */
  public class LoggingExternalCacheKeyGenerator extends ExternalCacheKeyGenerator {
      private static final Logger log = LoggerFactory.getLogger(LoggingExternalCacheKeyGenerator.class);
  
      private final ExternalCacheKeyGenerator delegate;
  
      public LoggingExternalCacheKeyGenerator(String productIdentifier, ExternalCacheKeyGenerator delegate) {
          super(productIdentifier);
          this.delegate = requireNonNull(delegate);
      }
  
      @Override
      protected String encode(String plain) {
          final String result = delegate.encode(plain);
          log.debug("Generated key {} from {}", result, plain);
          return result;
      }
  }