String写出到文件

File txt = new File("E:/log1.xml");            if(!txt.exists()) {                txt.createNewFile();            }            byte bytes[]=new byte[1024];            bytes=rtnXml.getBytes();            int len = bytes.length;            FileOutputStream fos=new FileOutputStream(txt);            fos.write(bytes,0,len);            fos.write(bytes);            fos.close();