通过缓冲区复制文本文件

/*通过缓冲区复制文本文件
通过缓冲区复制一个.java文件。
*/
import java.io.*;
class  CopyTextByBuf
{
public static void main(String[] args)
{
BufferedReader bufr = null;//读取
BufferedWriter bufw = null;//写入

try
{
bufr = new BufferedReader(new FileReader("BufferedWriterDemo.java"));//读取
bufw = new BufferedWriter(new FileWriter("bufWriter_copy.txt"));//写入

String line = null;
while ((line= bufr.readline())!=null)//判断非空，读取行
{
bufw.write(line);//循环写入行
bufw.newLine();//换行
bufw.flush();//刷新
}
}
catch (IOException e)
{
throw new RuntimeException("读写失败");
}
finally
{
try
{
if(bufr!=null)//判断非空
bufr.close();
}
catch (IOException e)
{
throw new RuntimeException("读取关闭失败");
}

try
{
if(bufw!=null)//判断非空
bufw.close();
}
catch (IOException e)
{
throw new RuntimeException("写入关闭失败");
}
}
}
}