replacing email address with email link

[limpan luring]

I want to do some filtering of raw text from text files or database entries to publish on a web site.
The problems include filtering out existing html tags, replacing email addresses with html email links, and creating html links from web addresses (starting with http )
The idea is to do it in a general enough way to make it easy to add and replace filters later on.

To start with I'd like input for howto make the replacements.
Has anyone done this in a good/not so good way?

[ October 24, 2004: Message edited by: limpan luring ]
[ October 24, 2004: Message edited by: limpan luring ]

[Tony Morris]

http://htmlparser.sf.net

[limpan luring]

Thanx. Had a quick look at htmlparser, but it seems to be a bit overkill for my purposes.

Here's what I did (quick and dirty):

  
public class HTMLFilter{
 
    Pattern email;
    Pattern html;
    Pattern brtag;
    Pattern bold;
 
    public HTMLFilter(){
email = Pattern.compile("\\b[a-z]+\\S[@]\\S[a-z.]+\\S[a-z]");
html = Pattern.compile("<.+?>");
bold = Pattern.compile("\\*.+\\*");
brtag = Pattern.compile("$", Pattern.MULTILINE);
    }
 
    public String removeHTML(String in){
Matcher matcher = html.matcher(in); 
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
    matcher.appendReplacement(sb,"");
} 
matcher.appendTail(sb);
return sb.toString ();
    }
 
    public String makeBR(String in){
Matcher matcher = brtag.matcher(in); 
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
    matcher.appendReplacement(sb,"<br>");
} 
matcher.appendTail(sb);
return sb.toString ();
    }
 
    public String makeEmailLinks(String in){
 
Matcher matcher = email.matcher(in); 
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
    matcher.appendReplacement(sb,"<a href = 'mailto:" + matcher.group() + "'>" + matcher.group() + "</a>");
} 
matcher.appendTail(sb);
return sb.toString ();
    }

... and so on.
Applying these methods one after another (as is the idea behind the stuff) seems to be a bit inefficient, with all the String stuff going on. Any ideas on how to improve this? Not too sure about the regexps either ...
[ October 24, 2004: Message edited by: limpan luring ]

[Jeroen Wenting]

why reinvent the wheel?
You may think using an existing toolkit is overkill now but before you know you've rewritten over half the functionality...

As to email addresses: that's highly unreliable (unless your data is tabulated to tell you exactly where they are).
There's too many possible things that can go wrong.
is x@y.z an email address or not?
And what about a.b@c.e.f.g ?