List<> list=new ArrayList<>();
...
String[] arrStr=list.toArray(new String[list.size()]);





//String[] arrStr=(String[])list.toArray();//这样会报错,因为add()添加的是Object对象,list.toArray返回的只能是Object[]
//不能将Object[] 转化为String[].转化的话只能是取出每一个元素再转化

正确是这样
Object[] arr = list.toArray();
for (int i = 0; i < arr.length; i++) {
	String e = (String) arr[i];
	System.out.println(e);
}


--------------------------
T<> array = list.toArray(T<> arr);