/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.pattern;
  
  import java.util.List;
  import java.util.regex.Pattern;
  
  public class ReplacingCompositeConverter<E> extends CompositeConverter<E> {
  
      Pattern pattern;
      String regex;
      String replacement;
  
      public void start() {
          final List<String> optionList = getOptionList();
          if (optionList == null) {
              addError("at least two options are expected whereas you have declared none");
              return;
          }
  
          int numOpts = optionList.size();
  
          if (numOpts < 2) {
              addError("at least two options are expected whereas you have declared only " + numOpts + "as [" + optionList
                      + "]");
              return;
          }
          regex = optionList.get(0);
          pattern = Pattern.compile(regex);
          replacement = optionList.get(1);
          super.start();
      }
  
      @Override
      protected String transform(E event, String in) {
          if (!started)
              return in;
          return pattern.matcher(in).replaceAll(replacement);
      }
  }