method "mkString"

mkString.java

public static String mkString(Iterable<?> values, String start, String sep, String end){
	// if the array is null or empty return an empty string
	if(values == null || !values.iterator().hasNext())
		return "";
	
	// move all non-empty values from the original array to a new list (empty is a null, empty or all-whitespace string)
	List<String> nonEmptyVals = new LinkedList<String>();
	for (Object val : values) {
		if(val != null && val.toString().trim().length() > 0){
			nonEmptyVals.add(val.toString());
		}
	}
	
	// if there are no "non-empty" values return an empty string
	if(nonEmptyVals.size() == 0)
		return "";
	
	// iterate the non-empty values and concatenate them with the separator, the entire string is surrounded with "start" and "end" parameters
	StringBuilder result = new StringBuilder();
	result.append(start);
	int i = 0; 
	for (String val : nonEmptyVals) {
		if(i > 0)
			result.append(sep);
		result.append(val);
		i++;
	}
	result.append(end);
	
	return result.toString();
}
public static String mkString(Iterable<?> values, String sep){
	return mkString(values, "", sep, "");
}
public static String mkString(Iterable<?> values){
	return mkString(values, "", "", "");
}

// same methods with array parameter
public static String mkString(Object[] values, String start, String sep, String end){
	return mkString(Arrays.asList(values), start, sep, end);
}
public static String mkString(Object[] values, String sep){
	return mkString(Arrays.asList(values), sep);
}
public static String mkString(Object[] values){
	return mkString(Arrays.asList(values));
}