package
import *;
public class OutputStreamWriter
{
    public static void main(String args[])  throws Exception
    {
        File f1=new File("D:"+File.separator+"test.txt");
        File f2=new File("D:"+File.separator+"demo.txt");
        FileOutputStream out=new FileOutputStream(f1);
        FileInputStream in=new FileInputStream(f2);
        OutputStreamWriter output=null;
        output=new OutputStreamWriter(out);//说这行有错误
        InputStreamReader input=new InputStreamReader(in);
    }
}