Details
Major Description
I dont know how picky you are about performance, but I think it would be nice
for methods like this not to create new objects (StringBuffers) and copy over,
if it doesnt need to (e.g. if what you are searching for is not in the "text"
String). Also, if the text is empty, we can return it right away. And, my
profiler gets two StringBuffers and an arrayCopy here sometimes since we only
allocate enough for the original String. I think overall it is better to
allocate a little more (+20%) for the StringBuffer to reduce this possibility
and only have 1 StringBuffer to be garbage collected. Feel free to pick and
choose from any of these ideas. 
public static String replace(String text, String repl, String with, int max) {
could be written as:
public static String replace(String text, String repl, String with, int max)
{
if (isEmpty(text) || isEmpty(repl) || with == null || max == 0)
int start = 0, end = text.indexOf(repl, start);
if (end == -1) { return text; }
//add a bit of padding so we reduce the StringBuffer extend capacity
StringBuffer buf = new StringBuffer(text.length()
+ (text.length() < 20 ? 4 : text.length()/5));
while (end != -1) {
buf.append(text.substring(start, end)).append(with);
start = end + repl.length();
if (--max == 0)
{ break; } end = text.indexOf(repl, start);
}
buf.append(text.substring(start));
return buf.toString();
}
I tested it on the test cases in the javadoc and it worked fine.
Thanks!
Chris