//string数组转成list数组
String[] arr = new String[] {"str1", "str2"};
List<String> list = Arrays.asList(arr);
List<String> list = new ArrayList<String>();
list.add("str1");
list.add("str2");
int size = list.size();
//使用了第二种接口,返回值和参数均为结果
String[] arr = (String[])list.toArray(new String[size]);