/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, 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.access.pattern;
  
  import java.util.Arrays;
  
  import ch.qos.logback.access.spi.IAccessEvent;
  import ch.qos.logback.core.util.OptionHelper;
  
  public class RequestParameterConverter extends AccessConverter {
  
    String key;
  
    public void start() {
      key = getFirstOption();
      if (OptionHelper.isEmpty(key)) {
        addWarn("Missing key for the request parameter");
      } else {
        super.start();
      }
    }
  
    public String convert(IAccessEvent accessEvent) {
      if (!isStarted()) {
        return "INACTIVE_REQUEST_PARAM_CONV";
      }
  
      String[] paramArray = accessEvent.getRequestParameter(key);
      if (paramArray.length == 1) {
        return paramArray[0];
      } else {
        // for an array string {"a", "b"} named 'sa', Array.toString(sa) returns the string 
        // "[a, b]".
        return Arrays.toString(paramArray);
      }
    }
  
  }