java.util.Arrays.toString(...) for debugging

AVOID default toString(). Using the common debugging technique of printing intermediate values on the console with arrays is good, but requires calling a library method to get the results you expect. Arrays are a subclass of Object as ever other object is, and therefore the toString() method is defined for every array. The results will very likely disappoint you.

String[] abc = {"a", "b", "c"};
System.out.println(abc);   // println calls toString() on object parameters.

This displays the relatively unhelpful "[L", element type, ";@", and hexadecimal memory address of the array.

[Ljava.lang.String;@f6f1b6

USE java.util.Arrays.toString(...) and you'll get something much more readable. An import java.util.*; statement avoids the extra package qualifier.

String[] abc = {"a", "b", "c"};
System.out.println(java.util.Arrays.toString(abc));

This produces the following output, which is the same as toString() applied to a List.

[a, b, c]