JAVA下载文件

JAVA下载文件：
String formatsStr = "文件内容";
response.setContentType("application/octet-stream;charset=utf-8");
response.setContentLength(formatsStr.getBytes().length);
response.setHeader("Content-disposition", "attachment;filename=formats.xml");
Writer out = response.getWriter();
out.write(formatsStr);
out.flush();
out.close();

如果不加response.setHeader("Content-disposition", "attachment;filename=formats.xml");这一段代码，就直接显示在页面中