//list转数组
List<String> list = new ArrayList<>();
list.add("1");
list.add("2");
list.add("3");
String[] strings = new String[list.size()];
list.toArray(strings);
for (int i = 0; i < strings.length; i++) {
System.out.println(strings[i]);
}
//数组转list
String[] strings1 = {"7","8","9"};
List<String> list1 = Arrays.asList(strings1);
list1.forEach(l->{
System.out.println(l);
});