springboot表单提交之validator校验

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate.validator/hibernate-validator -->
        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>6.1.5.Final</version>
        </dependency>


        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

package com.ctvit.validatordemo.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.Pattern;
import java.io.Serializable;

/**
 * 用户名，密码，邮箱，身份证
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User implements Serializable {
    @NotEmpty(message="用户名不能为空")
    @Length(min=6,max = 12,message="用户名长度必须位于6到12之间")
    private String userName;


    @NotEmpty(message="密码不能为空")
    @Length(min=6,message="密码长度不能小于6位")
    private String passWord;

    @Email(message="请输入正确的邮箱")
    private String email;

    @Pattern(regexp = "^(\\d{18,18}|\\d{15,15}|(\\d{17,17}[x|X]))$", message = "身份证格式错误")
    private String idCard;

}

package com.ctvit.validatordemo.controller;

import com.ctvit.validatordemo.pojo.User;
import org.springframework.validation.BindingResult;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;
import java.util.List;

@RestController
public class UserController {

    @PostMapping("/Register")
    public String Register(@Valid User user, BindingResult bindingResult){//一个BindingResult对应一个@Valid注解的参数，用来表示校验消息
        StringBuffer stringBuffer = new StringBuffer();//使用StringBuffer拼接错误信息，比如用户名为空，长度等
        if(bindingResult.hasErrors()){//判读是否携带错误信息
            List<ObjectError> list =bindingResult.getAllErrors();//获取所有错误信息对象
            for (ObjectError objectError:list) {//遍历对象，获取错误的具体信息
                //将所有信息进行拼接
                stringBuffer.append(objectError.getDefaultMessage());
                stringBuffer.append("---");
            }
        }
        return stringBuffer!=null?stringBuffer.toString():"";//将错误信息返回
    }
}