很好地打印Java集合(toString不会返回漂亮的输出)

list.stream().forEach(System.out::println);

String result = StringUtils.join(list.iterator(), ", ");
System.out.println(result);

String result = Joiner.on(", ").join(list);
System.out.println(result);

public static <T> String formatCollection(Collection<T> collection) {
    StringBuilder sb = new StringBuilder();
    sb.append("[");
    for (T element : collection) {
        sb.append(element).append(", ");
    }
    if (sb.length() > 1) {
        sb.setLength(sb.length() - 2);
    }
    sb.append("]");
    return sb.toString();
}