【Thymeleaf】ModelAndView中设置一个值，页面上显示此值。

设值部分：

@Controller
public class UserCtrl {
...
    
    @Autowired
    private UserService userService;
    
    @PostMapping(value="/userRegister")
    public ModelAndView register(String uname,String pswd,String repswd,String email) {
        ModelAndView mav=new ModelAndView("register");
        
        boolean isNameUnique=userService.isUniqueName(uname);
        if(!isNameUnique) {
            mav.addObject("errMsg", uname+"已经存在了。");
            return mav;
        }
        
        boolean isEmailUnique=userService.isUniqueEmail(email);
        if(!isEmailUnique) {
            mav.addObject("errMsg", email+"已经存在了。");
            return mav;
        }
        
        boolean added=userService.addOneUser2Db(uname, repswd, email);
        
        if(added) {
            logger.info("User:{} added.",uname);
            return new ModelAndView("login");
        }else {
            return new ModelAndView("error");
        }
    }
}

页面上显示此值：

<div class="block-body">
<form action="userRegister" method="post">
    <label>用户名</label>
    <input type="text" name="uname" class="span12">
    <label>密码</label>
    <input type="password" name="pswd" class="span12">
    <label>再次输入密码</label>
    <input type="password" name="repswd" class="span12">
    <label>邮件地址</label>
    <input type="text" name="email" class="span12">
    <input type="submit" value="Submit" class="btn btn-primary pull-right"/>
    <div class="clearfix"><span th:text="${errMsg}">errMsg</span></div>
</form>
</div>

前作：https://www.cnblogs.com/heyang78/p/12813594.html

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