@ModelAttribute可以注释方法和参数
@ModelAttribute注释方法
@ModelAttribute注释方法该方法会在controller的所有方法之前被执行。通过Model将value设定到相应的key中。
(1)注释返回值为void的方法，通过传入Model添加属性值
@RestController@RequestMapping("/usrcontroller")public class UserController { UserService us = new UserService(); @ModelAttribute public void findUserById(@RequestParam Long uid, Model model) { model.addAttribute("user", us.getUser(uid)); } @GetMapping(path="/getuser") @ResponseBody public String getUser(Model model) { User u = (User)(model.getAttribute("user")); System.out.println(u.name); return u.name; }}
(2)注释返回值为具体类型的。通过添加属性（属性名为返回值的头字母小写,例如返回值为Group，属性为group）将返回值添加实际结果类似与model.addAttribute("returnvaluename", var);
@RestController@RequestMapping("/groupcontroller")public class GroupController { @ModelAttribute public Group getGroupId(@RequestParam Long gid) { Group g = new Group(); g.groupName = "group_"+gid; g.groupId = gid; return g; //same as Model.addAttribute("group", g) } @GetMapping(path="/getgroup") @ResponseBody public String getGroup(Model model) { Group g = (Group)model.getAttribute("group"); String gStr = "group(id:" + g.groupId + "," + g.groupName + ")"; System.out.println(gStr); return gStr; }}
(3)指定属性的名称
//类似于Model.addAttribute("defaultuser", User)@ModelAttribute("defaultuser")public User createDefaultUser() { return new User("defaultUsr","SH", 22, true);}@GetMapping(path="/checkdefaultuser")@ResponseBodypublic String checkDefaultUser(@ModelAttribute("defaultuser") User dfUsr) { String dfUsrStr = "Default user("+dfUsr.name + "," + dfUsr.address + "," + dfUsr.age + "," + dfUsr.isMan + ")"; System.out.println(dfUsrStr); return dfUsrStr;}
@ModeAttribute注释方法的参数
@ModelAttribute("defaultuser")public User createDefaultUser() { return new User("defaultUsr","SH", 22, true);}@GetMapping(path="/checkdefaultuser")@ResponseBodypublic String checkDefaultUser(@ModelAttribute("defaultuser") User dfUsr) { String dfUsrStr = "Default user("+dfUsr.name + "," + dfUsr.address + "," + dfUsr.age + "," + dfUsr.isMan + ")"; System.out.println(dfUsrStr); return dfUsrStr;}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。
本文标题: Spring boot @ModelAttribute标注的实现
以上就上有关Springboot@ModelAttribute标注的实现的全部内容，学步园全面介绍编程技术、操作系统、数据库、web前端技术等内容。