package com.atlassian.logging.log4j;
   
   import org.apache.log4j.helpers.FormattingInfo;
   import org.apache.log4j.helpers.PatternConverter;
   import org.apache.log4j.spi.LoggingEvent;
   
   /**
    * PatternParser that will suffix newline characters with a custom separator (default four spaces ). This is
    * to better highlight that log messages are being injected when logging user entered information.
   *
   * @since v1.2
   */
  public class NewLineLogMessagePatternParser extends CategoryCollapsingPatternParser
  {
      // Line ending combos include UNIX and MAC = \n, WINDOWS = \r\n, MAC pre OSX = \r the next major OS will need to choose \n\r
      private String lineIndent;
  
      public NewLineLogMessagePatternParser(final String pattern, final String lineIndent, final int fqNameCollapsePrecision)
      {
          super(pattern, fqNameCollapsePrecision);
          this.lineIndent = lineIndent;
      }
  
      @Override
      protected void finalizeConverter(final char c)
      {
          switch(c)
          {
              // m is the character the log4j 1.2 uses to represent the log message passed along with
              // with the logging event
              case 'm':
                  addConverter(new LineEndingStrippingPatternConverter(formattingInfo, lineIndent));
                  break;
              default:
                  super.finalizeConverter(c);
                  break;
          }
      }
  
      /**
       * Append an indent to \r, \n, \r\n combination whilst preserving the original character
       */
      protected static class LineEndingStrippingPatternConverter extends PatternConverter
      {
          private final String lineIndent;
  
          LineEndingStrippingPatternConverter(final FormattingInfo info, final String lineIndent)
          {
              super(info);
              this.lineIndent = lineIndent;
          }
  
          @Override
          public String convert(LoggingEvent event)
          {
              return LogMessageUtil.appendLineIndent(event.getRenderedMessage(), lineIndent);
          }
      }
  }