OutputStreamWriter osw, osw.append(buffer); 这样用对吗？

Question

                File fa=new File("E:/a.txt"); FileInputStream fais=new FileInputStream(fa); InputStreamReader isr=new InputStreamReader(fais,"UTF-8"); StringBuffer sbf=new StringBuffer(); while(isr.ready()){ sbf.append((char)isr.read()); } isr.close(); fais.close(); File fb=new File("E:/b.txt"); FileOutputStream fbos=new FileOutputStream(fb); OutputStreamWriter osw=new OutputStreamWriter(fbos,"UTF-8"); osw.append(sbf); //buffer直接带入，能这样写吗？ osw.close(); fbos.close();