Java: function for arrays like PHP's join()?

Given:

String[] a = new String[] { "Hello", "World", "!" };

Then as an alternative to coobird's answer, where the glue is ", ":

Arrays.asList(a).toString().replaceAll("^\\[|\\]$", "")

Or to concatenate with a different string, such as " & ".

Arrays.asList(a).toString().replaceAll(", ", " & ").replaceAll("^\\[|\\]$", "")

However... this one ONLY works if you know that the values in the array or list DO NOT contain the character string ", ".