springmvc 添加@ResponseBody

1.添加ResponseBody之后的话 返回字符串的时候 就是一个字符串、

@RequestMapping(value = "/{bookId}/detail.do",method = RequestMethod.GET)

@ResponseBody

private String detail(@PathVariable("bookId")Long bookId ,Model model){

 

if(bookId == null){

 

return "redirect:/book/list";

}

Book book = bookService.getById(bookId);

 

if(book == null){

return "forward:/book/list";

}

 

model.addAttribute("detail",book);

 

return "detail";

}

 

2. 如果不添加ResponseBody的话 model对象才能绑定到jsp的页面，就会返回一个对象