springboot 服务端表单验证

        org.springframework.boot
            spring-boot-starter-validation
        org.springframework.boot
            spring-boot-starter-web
        

public class Users {
    /*@NotNull(message = "userId不能为空")*/
    @NotNull(message = "{userId.notnull}")
    private Integer userId;
    /*@NotBlank(message = "userName不能为空")*/
    @NotBlank(message = "{userName.notnull}")
    private String userName;
    /*@NotBlank(message = "userSex不能为空")*/
    @NotBlank(message = "{userSex.notnull}")
    private String userSex;
    /*@NotBlank(message = "password不能为空")*/
    @NotBlank(message = "{password.notnull}")
    private String password;

    public Users(@NotNull Integer userId, @NotBlank String userName, @NotEmpty String userSex, @NotNull String password) {
        this.userId = userId;
        this.userName = userName;
        this.userSex = userSex;
        this.password = password;
    }

    public Users() {
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserSex() {
        return userSex;
    }

    public void setUserSex(String userSex) {
        this.userSex = userSex;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "Users{" +
                "userId=" + userId +
                ", userName=‘" + userName + ‘\‘‘ +
                ", userSex=‘" + userSex + ‘\‘‘ +
                ", password=‘" + password + ‘\‘‘ +
                ‘}‘;
    }
}

#用户ID不能为空
userId.notnull=\u7528\u6237ID\u4e0d\u80fd\u4e3a\u7a7a 
#用户姓名不能为空
userName.notnull=\u7528\u6237\u59d3\u540d\u4e0d\u80fd\u4e3a\u7a7a
#用户性别不能为空
userSex.notnull=\u7528\u6237\u6027\u522b\u4e0d\u80fd\u4e3a\u7a7a
#用户密码不能为空
password.notnull=\u7528\u6237\u5bc6\u7801\u4e0d\u80fd\u4e3a\u7a7a

　　/*
    *
    * @Validated 对该对象进行数据校验
    *
    * BindingResult：users对象校验不合法的信息
    *
    * 如果有多个对象需要进行校验，那么每个对象后面都需要加bindingResult对象
    *
    * SpringMvc会将users放到model对象中,防止前端报错。model中key的名称会使用对象的类型并且用驼峰规则来命名，可以通过@ModelAttribute自定义key
    *
    * */
    @RequestMapping("/addUser")
    public String addUser(@ModelAttribute("u") @Validated Users users, BindingResult bindingResult) {
        //hasErrors()是否含有关于数据校验的错误信息
        if(bindingResult.hasErrors()){
            return "addUser";
        }
        return "OK";
    }

DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
html xmlns:th="http://www.thymeleaf.org">
head>
    link rel="shortcut icon" href="../resources/favicon.ico" th:href="@{/static/favicon.ico}">
    title>springbootjdbctitle>
head>
body>
    form th:action="@{/user/addUser}" method="post">
        @NotBlank-string：input type="text" name="userName">font color="red">span th:errors="${u.userName}">span>font>br>
        @NotNull-Integer：input type="text" name="userId">font color="red">span th:errors="${u.userId}">span>font>br>
        @NotEmpty-string：input type="text" name="userSex">font color="red">span th:errors="${u.userSex}">span>font>br>
        @NotNull-string：input type="text" name="password">font color="red">span th:errors="${u.password}">span>font>br>
        input type="submit" value="OK">
    form>
body>
html>

　　/*
    * BindingResult类型是针对于实体类的，这里无法使用，想要返回错误信息，需要配置全局异常信息页面
    * */
    @RequestMapping("/findUser")
    public String findUser(@NotBlank(message = "用户名不能为空") String userName) {
        System.out.println(userName);
        return "OK";
    }

@Configuration
public class GlobalException implements HandlerExceptionResolver {

    /*
     * httpServletRequest产生异常的请求对象
     * httpServletResponse产生异常的响应对象
     * handler此次产生异常的handler对象
     * e 产生异常的异常对象
     * */
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler, Exception e) {
        ModelAndView mv = new ModelAndView();
        //判断不同异常类型，做不同视图跳转
        if(e instanceof ConstraintViolationException){
            mv.setViewName("findUser");
        }
        mv.addObject("error", e.getMessage().split(":")[1]);
        return mv;
    }
}

DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
html xmlns:th="http://www.thymeleaf.org">
head>
    link rel="shortcut icon" href="../resources/favicon.ico" th:href="@{/static/favicon.ico}">
    title>springbootjdbctitle>
head>
body>
    form th:action="@{/user/findUser}" method="post">
        userName：input type="text" name="userName">font color="red">span th:text="${error}">span>font>br>
        input type="submit" value="OK">
    form>
body>
html>