public String replace(String from, String to, String source)
{
if (source == null || from == null || to == null)
return null;
StringBuffer bf = new StringBuffer("");
int index = -1;
while ((index = source.indexOf(from)) != -1)
{
bf.append(source.substring(0, index) + to);
source = source.substring(index + from.length());
index = source.indexOf(from);
}
bf.append(source);
return bf.toString();
}