Question

I am writing a private utility method in a Spring Controller.

I need to use either StringBuffer or StringBuilder. The former is thread-safe, the latter is not, but the latter is much faster.

Basically, it looks like this:

private String buildTextToDisplay() {
    StringBuffer sb = new StringBuffer();
    sb.append( ... );
    return sb.toString();
}

Obviously, I don’t want two sessions to call this simultaneously and return garbage.

Answer 1

Since sb is a local variable, it doesn’t need to be thread safe. (Each thread would have its own reference to a unique StringBuilder, right?)