Conversion between arrays and collections

1.List <String> array into String [] array

方法为：

List<String> list = new ArrayList<>();
list.add("1");
list.add("2");

String[] a = list.toArray(new String[0]);

1. String [] arrays of arrays is converted into List <String>

方法为：

String[] a = {"1","2"};

List<String> list = Array.asList(a);