@NotNull：不能为null，但可以为empty
@NotEmpty：不能为null，而且长度必须大于0
@NotBlank：只能作用在String上，不能为null，而且调用trim()后，长度必须大于0
@Data @Entity @EqualsAndHashCode(callSuper = true) @ApiModel(value = "User Entity", description = "User Entity") public class User extends BaseEntity { @Column @NotEmpty(message = "用户工号不能为空") @ApiModelProperty(value = "工号", example = "680059") private String userCode; @Column @NotNull(message = "用户姓名不能为空") @Size(min = 6, max = 12, message = "用户姓名必须是6-12个字符") @ApiModelProperty(value = "姓名", example = "马颖华") private String userName; @Column @ApiModelProperty(value = "密码", example = "123456") private String password; }接口需要校验的参数上加上@Valid注解，当请求参数传递到接口的时候Validator就自动完成校验了，校验的结果就会封装到BindingResult中去，如果有错误信息我们直接返回给前端
@PostMapping("/add") @ApiOperation(value = "add User", notes = "add User") public String add(Model model, @Valid User user, BindingResult bindingResult) { // 判断是否含有校验不匹配的参数错误 if (bindingResult.hasErrors()) { // 获取所有字段参数不匹配的参数集合 List<FieldError> fieldErrorList = bindingResult.getFieldErrors(); Map<String, Object> result = new HashMap<>(fieldErrorList.size()); fieldErrorList.forEach(error -> { // 将错误参数名称和参数错误原因存于map集合中 result.put(error.getField(), error.getDefaultMessage()); }); model.addAttribute("errors", result); return PARAM_ERROR; } userService.save(user); return REDIRECT; } <!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <head th:replace="common/header::layout(~{::title})"> <title>参数错误</title> </head> <body> <h3>对不起，提交参数不符合要求！</h3> <table class="table table-striped projects"> <tr th:each="item,userStat:${errors}"> <td th:text="${userStat.index}+1"></td> <td th:text="${userStat.current.key}"></td><!-- key--> <td th:text="${userStat.current.value}"></td><!-- value--> </tr> </table> <a href="/index">返回首页</a> </body> </html>