/**
    * 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 chapters.appenders;
  
  import ch.qos.logback.classic.spi.ILoggingEvent;
  import ch.qos.logback.core.AppenderBase;
  import ch.qos.logback.core.Layout;
  
  public class CountingConsoleAppender extends AppenderBase<ILoggingEvent> {
      static int DEFAULT_LIMIT = 10;
      int counter = 0;
      int limit = DEFAULT_LIMIT;
  
      Layout<ILoggingEvent> layout;
  
      public void setLimit(int limit) {
          this.limit = limit;
      }
  
      public int getLimit() {
          return limit;
      }
  
      @Override
      public void start() {
          if (this.layout == null) {
              addError("No layout set for the appender named [" + name + "].");
              return;
          }
  
          String header = layout.getFileHeader();
          System.out.print(header);
          super.start();
      }
  
      public void append(ILoggingEvent event) {
          if (counter >= limit) {
              return;
          }
          // output the events as formatted by patternLayout
          String eventStr = this.layout.doLayout(event);
  
          System.out.print(eventStr);
  
          // prepare for next event
          counter++;
      }
  
      public Layout<ILoggingEvent> getLayout() {
          return layout;
      }
  
      public void setLayout(Layout<ILoggingEvent> layout) {
          this.layout = layout;
      }
  }