其实只要在form表单中的input标签下，写
<p th:if="${#fields.hasErrors(‘变量名‘)}" th:errors="*{变量名}"></p>
示例
1 <p th:if="${#fields.hasErrors(‘age‘)}" th:errors="*{age}"></p>
完整代码
1 <!DOCTYPE HTML> 2 <html xmlns:th="http://www.thymeleaf.org"> 3 <!-- 引入属性xmlns:th="http://www.thymeleaf.org" 来启用thymeleaf模板 4 thymeleaf 相当于jsp --> 5 <head> 6 <title>添加用户</title> 7 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 8 </head> 9 <body> 10 <form th:action="@{/adduser}" th:object="${user}" method="post"> 11 <label for="name">姓名</label> 12 <input type="text" th:field="*{name}" id="name" placeholder="Name"> 13 14 <p th:if="${#fields.hasErrors(‘name‘)}" th:errors="*{name}"></p> 15 16 17 <label for="age">年龄</label> 18 <input type="text" th:field="*{age}" id="age" placeholder="age"> 19 20 <p th:if="${#fields.hasErrors(‘age‘)}" th:errors="*{age}"></p> 21 22 23 <label for="email">邮箱</label> 24 <input type="text" th:field="*{email}" id="email" placeholder="Email"> 25 <p th:if="${#fields.hasErrors(‘email‘)}" th:errors="*{email}"></p> 26 27 28 <input type="submit" value="保存"> 29 </form> 30 </body> 31 </html>
原文：https://www.cnblogs.com/hzyhx/p/11105162.html