IRC Message Parser Class

package irc;

import java.util.ArrayList;

public class IRCMessage{
    public boolean valid;

    public String message;

    public String prefix;
    public String command;
    public String parameter;

    public String servername;
    public String identification;

    public String nick;
    public String user;
    public String host;

    public String[] parameters;
    public String trailing;

    public IRCMessage(String message){
        message = message.trim();
        this.message = message;

        valid = false;

        prefix = null;
        command = null;
        parameter = null;

        servername = null;
        identification = null;

        nick = null;
        user = null;
        host = null;

        parameters = null;
        trailing = null;

        try{
            if(message.length() > 0){
                String[] parts;
                if(message.charAt(0) == ':'){
                    parts = message.split(" ", 2);
                    prefix = parts[0].substring(1);
                    message = parts[1].trim();

                    if(prefix.indexOf("!") != -1){
                        identification = prefix;
                        nick = identification;
                        if(identification.indexOf("@") != -1){
                            parts = nick.split("@", 2);
                            nick = parts[0];
                            host = parts[1];
                        }
                        if(nick.indexOf("!") != -1){
                            parts = nick.split("!", 2);
                            nick = parts[0];
                            user = parts[1];
                        }
                    }else{
                        servername = prefix;
                    }
                }
                command = message.substring(0, message.indexOf(" "));
                parameter = message.substring(command.length());
                if(parameter.indexOf(":") != -1){
                    parts = parameter.split(":", 2);
                    parameter = parts[0];
                    trailing = parts[1];
                }
                parameter = parameter.trim();
                parameters = parameter.split(" ");
                ArrayList<String> pars = new ArrayList<String>();
                int i;
                for(i = 0 ; i < parameters.length; i++){
                    if(parameters[i].length() > 0){
                        pars.add(parameters[i]);
                    }
                }
                parameters = new String[pars.size()];
                for(i = 0 ; i < pars.size(); i++){
                    parameters[i] = pars.get(i);
                }
                valid = true;
            }
        }catch(Exception exception){}
    }

    public String format(){
        if(valid){
            String formatted = "";
            if(prefix != null){
                formatted += ":";
                if(servername != null){
                    formatted += servername;
                }else{
                    formatted += nick;
                    if(user != null){
                        formatted += "!" + user;
                    }
                    if(host != null){
                        formatted += "!" + host;
                    }
                }
                formatted += " ";
            }
            formatted += command;
            int i;
            for(i = 0; i < parameters.length; i++){
                formatted += " " + parameters[i];
            }
            if(trailing != null){
                formatted += " :" + trailing;
            }
            return formatted;
        }else{
            return null;
        }
    }
}