i18n.username=Username
i18n.password=Password
i18n.username=Username
i18n.password=Password
i18n.username=\u7528\u6237\u540D
i18n.password=\u5BC6\u7801
HttpMessageConverter<T> 是 Spring3.0新添加的一个接 口，负责将请求信息转换为一个对象（类型为 T），将对象（ 类型为 T）输出为响应信息 @RequestMapping("/testResponseEntity")
public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException{
byte [] body = null;
ServletContext servletContext = session.getServletContext();
InputStream in = servletContext.getResourceAsStream("/files/abc.txt");
body = new byte[in.available()];
in.read(body);
HttpHeaders headers = new HttpHeaders();
headers.add("Content-Disposition", "attachment;filename=abc.txt");
HttpStatus statusCode = HttpStatus.OK;
ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(body, headers, statusCode);
return response;
}