Dec2Hex.java

//Edit to push file to github for presentation


import java.util.logging.*;

class Dec2Hex
{
    //Declaring the class logger
    private static final Logger D2HLog = Logger.getLogger(Logger.GLOBAL_LOGGER_NAME);
    
    //Class static initialization block to format console handler for Logger and only output message removing other metadata
    static {
        ConsoleHandler handler = new ConsoleHandler();
        handler.setFormatter(new SimpleFormatter() {
            @Override public String format(LogRecord myRecord) {
            	return "\n" + formatMessage(myRecord) + "\n";
            }
        });
        D2HLog.setUseParentHandlers(false);
        D2HLog.addHandler(handler);
      }
    
    //main function calls sub routines to convert int to hex
    public static void main(String[] args)
    {
        if(nullInputCheck(args))
        {
            if(possitiveIntCheck(intParse(args)))
            {
            	D2HLog.log(Level.INFO, "Converting the Decimal Value {0} to Hex...", Integer.toString(intParse(args)));
            	D2HLog.log(Level.INFO, "Hexadecimal representation is: {0}", hexConverter(intParse(args)));                       
            }else{
                D2HLog.warning("Error - Only positive integer to be entered");
            }
        }else{
            D2HLog.warning("Error - Nothing input");
        }
    }
    
    //function checks that there has been an input supplied
    private static boolean nullInputCheck (String[] args)
    {
        return args.length>0;
    }
    
    //function attempts to parse the input to an int and returns a negative int if process fails. 
    public static int intParse(String[] args)
    {
        try
        {
            return Integer.parseInt(args[0]);
        }catch (NumberFormatException e){
            return -1;
        }       
    }
    
    //function checks if the parsed input is a positive int
    public static boolean possitiveIntCheck(int i)
    {       
        return i>0;
    }
    
    
    //function converts the validated input to hex if all validation gates passed
    private static String hexConverter(int i)
    {
        char[] ch={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        StringBuilder result = new StringBuilder();
        for (; i!=0; i=i/16) {        	
            result.insert(0,ch[i%16]);
        }
        return result.toString();
    }
}