| 92 | } |
| 93 | |
| 94 | public static <E> E randomChoice(Collection<? extends E> input) { |
| 95 | int idx = new SecureRandom().nextInt(input.size()); |
| 96 | Iterator<? extends E> iterator = input.iterator(); |
| 97 | |
| 98 | if (input instanceof List) { // optimization |
| 99 | return ((List<? extends E>) input).get(idx); |
| 100 | } else { |
| 101 | Iterator<? extends E> iter = input.iterator(); |
| 102 | for (int i = 0; i < idx; i++) { |
| 103 | iter.next(); |
| 104 | } |
| 105 | return iter.next(); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | public static String exceptionToString(Throwable throwable) { |
| 110 | StringWriter sw = new StringWriter(); |