构造方法:
BufferedReader(Reader in) :
BufferedReader br=new BufferedReader(new FileReader("a.txt"));
//读数据
// int len;
// while((len=br.read())!=-1){
// System.out.print((char)len);
// }
int len;
char[] ch=new char[1024];
while((len=br.read(ch))!=-1){
System.out.print(new String(ch,0,len));
}
br.close();