java文件io操作

    FileReader fr=new FileReader("D:\\Demo.txt");
    char[] ch=new char[2];
    int len=0;
    while((len=fr.read(ch))!=-1)
    {
        System.out.print(new String(ch, 0, len));
    }

    FileReader fr=new FileReader("D:\\Demo.txt");
    int cl=0;
    while((cl=fr.read())!=-1)
    {
        System.out.println((char)cl);
    }