Replace token in an File

Question

Hi,
I'm searching for an easy way to change specific tokens in a file. For instance an HTML file specify <img src="http://www.site1.com/images/img.gif"> I would like to replace all occurences by
<img src="http://www.site2.com/imgs/old/img.gif"> for instance.
Is there an easy way to do this ? (streamtokenizer or something)
Examples are welcome,
Stephane

Answer 1

Hi Steve! One quick observation, if I may. Consider the following lines of code.
pos += o.length();
oldpos = pos;
pos does not need to be updated as above. Rather, you just need
oldpos = pos + o.length();That's because pos is being updated at the top of the loop. Also, you can move the declaration of pos out of the loop. The same applies for the creation of the StringBuffer object.
Here's a slightly different version of the code. If you can optimize it further, please let me know.
   public static String replace( String s, String oldToken, String newToken, boolean fAll )
      if ( ( s == null ) || ( oldToken == null ) || ( newToken == null ) )
         throw new IllegalArgumentException( "Null argument(s) seen" );
      int oldTokenLen = oldToken.length();
      StringBuffer sb = null;
      int oldPos = 0;
      int pos = s.indexOf( oldToken, oldPos );
      if ( oldPos > -1 )
         sb = new StringBuffer( s.length() );
      for(
          ; pos > -1
          ; pos = s.indexOf( oldToken, oldPos )
         sb.append( s.substring( oldPos, pos ) );
         sb.append( newToken );
         oldPos = pos + oldTokenLen;
         if ( !fAll )
            break;
      return ( ( oldPos > 0 ) ? sb.append( s.substring( oldPos ) ).toString() : s );
   }  // replaceCheers!