IO字符流FileReader读取数据
import java.io.*;class FileReaderDemo2{public static void main(String[] args) throws IOException{FileReader fr = new FileReader("demo.txt");int ch = 0;while((ch=fr.read())!=-1){System.out.print((char)ch);}/*int ch = fr.read();System.out.println(ch);int ch1 = fr.read();System.out.println(ch1);*/fr.close();}}?