Chat filtering

[ahmed yehia]

I am writing a method that can do some filtering and manipulations on a String intended for chat client.

The method main purpose is to recognize commands and returns the appropriate output and do some string replacements.

Here what I have come up with so far:

private static String filter(String in) {
    String op = "";
 if(in.trim().charAt(0) == '/') {
 if(in.substring(1).equalsIgnoreCase("time"))
op = "Its currently: " + new Date();
 else if(in.substring(1).equalsIgnoreCase("info"))
op = "My Info";
 else
op = "Unknown Command";
 
return op;
}
 
        op = in.replace("shit", "barnacle").replace("evil", "book");
        return op;
}

This seems to work a bit but it has limitations and performance hit in String replace methods.

I want to do it using better and efficient approach, I have looked at Pattern and Matcher replacement methods but don't seems to figure it out with this context.

Further I would like to pass for example: "/me grins" and get "Ahmed grins"

Any ideas would be appreciated.
Thanks in advance.

[Bill Shirley]

Originally posted by Ahmed Yehia:
I want to do it using better and efficient approach, I have looked at Pattern and Matcher replacement methods but don't seems to figure it out with this context.

Further I would like to pass for example: "/me grins" and get "Ahmed grins"

You're on the right track.
Read the docs over again and give it a try - you should be able to reimplement what you have with them. Once you have that it should scale better.

java.util.regex.Pattern
java.util.regex.Matcher
java.util.Scanner

I found myself recently using

java.lang.String.replaceAll() - which is shorthand for the above.

private String cleanPhoneNumber(String number)
{
// removed non-numeric items from a phone number string
// note: likely a better way to do this
String cleanNumber = number.replaceAll(":|-|(|)|.|+| ","");
return cleanNumber;
}

[ahmed yehia]

This one seems more logical:

    
private static String filter(String in) {
    String op = "";
    String cmd = "";
    String param = "";
 if(in.trim().charAt(0) == '/') {
 Pattern p = Pattern.compile("[^/]\\w+");
 Matcher m = p.matcher(in);
 if(m.find())
 cmd = m.group();
 
 Pattern p1 = Pattern.compile("[\\s].+");
 Matcher m1 = p1.matcher(in);
 if(m1.find())
 param = m1.group();
 
 if(cmd.equalsIgnoreCase("time"))
op = "Its currently: " + new Date();
 else if(cmd.equalsIgnoreCase("info"))
op = "My Information";
 else if(cmd.equalsIgnoreCase("me"))
 op = "Ahmed " + param.trim();
 else
op = "Unknown Command";
 
return op;
}
 
op = in.replace("shit", "barnacle").replace("evil", "book");
        return op;
}