public static void main(String[] args) {

// TODO Auto-generated method stub

FileReader fr = null;

FileWriter fw = null;

try {

fr = new FileReader("demo.txt");

fw = new FileWriter("cope.txt");

int ch = 0;

//每次只读一个字节

while ((ch = fr.read()) != -1) {

fw.write(ch);

}

} catch (Exception e) {

// TODO: handle exception

throw new RuntimeException("复制失败");

}finally {

if (fr != null) {

try {

fr.close();

} catch (Exception e2) {

// TODO: handle exception

}

}

if (fw != null) {

try {

fw.close();

} catch (Exception e2) {

// TODO: handle exception

}

}

}

}