public static void Print() throws FileNotFoundException,IOException{
BufferedReader br = new BufferedReader(new FileReader("E://项目/exam/src/com/itheima/a.txt"));
Writer fw = null;
List<Character> arrayList = new ArrayList<Character>();
//把文件中的字符存进ArrayList集合中
int ch;
while((ch=br.read())!=-1){
char c = (char)ch;
arrayList.add(c);