1.引入依賴

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

2.在需要校驗的引數上加@Valid註解

    @RequestMapping("/do_login")
    @ResponseBody
    public Result<Boolean> do_login(@Valid UserVo  userVo){
 

3.在需要檢驗的引數類裡面加註解

@NotNull：引數不能為空 

@Length(min = 32)：引數長度最小32

@IsMobile:這個是我們自定義的引數，在後面進行具體編寫

package com.example.miaosha_xdp.VO;

import lombok.ToString;
import lombok.Getter;
import lombok.Setter;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.NotNull;
@Getter
@Setter
@ToString
public class UserVo {
    @NotNull
    @IsMobile
    private String mobile;
    @NotNull
    @Length(min = 32)
    private String password;
}
 

4.自定義一個引數校驗器

我們照貓畫虎，利用@NotNull這個註解為參考來定義一個自己的校驗器。

4.1檢視@NotNull的原始碼

/*
 * Bean Validation API
 *
 * License: Apache License, Version 2.0
 * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
 */
package javax.validation.constraints;

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE_USE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Documented;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;
import javax.validation.constraints.NotNull.List;

/**
 * The annotated element must not be {@code null}.
 * Accepts any type.
 *
 * @author Emmanuel Bernard
 */
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
@Retention(RUNTIME)
@Repeatable(List.class)
@Documented
@Constraint(validatedBy = { })
public @interface NotNull {

	String message() default "{javax.validation.constraints.NotNull.message}";

	Class<?>[] groups() default { };

	Class<? extends Payload>[] payload() default { };

	/**
	 * Defines several {@link NotNull} annotations on the same element.
	 *
	 * @see javax.validation.constraints.NotNull
	 */
	@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
	@Retention(RUNTIME)
	@Documented
	@interface List {

		NotNull[] value();
	}
}
 

4.2 複製到我們的校驗器裡面進行修修改改

裡面的IsMobileValidator.class是我們自己的引數校驗類，用來定義具體的校驗策略。我們在後面會進行編寫。

package com.example.miaosha_xdp.validator;


import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * The annotated element must not be {@code null}.
 * Accepts any type.
 *
 * @author Emmanuel Bernard
 */
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {IsMobileValidator.class})
public @interface IsMobile {
    /**
     * 預設可以為空
     *
     * @return
     */
    boolean required() default false;

    /**
     * 校驗錯誤的提示資訊
     * @return
     */
    String message() default "手機號碼格式錯誤";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};


}

4.3定義我們自己的校驗類

package com.example.miaosha_xdp.validator;

import com.example.miaosha_xdp.util.ValidatorUtil;
import org.springframework.util.StringUtils;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.lang.annotation.Annotation;

public class IsMobileValidator implements ConstraintValidator<IsMobile, String> {
    private boolean required = false;

    /**
     * 初始化方法
     * 拿到我們的註解
     *
     * @param constraintAnnotation
     */
    @Override
    public void initialize(IsMobile constraintAnnotation) {
        required = constraintAnnotation.required();
    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        if (required) {
            return ValidatorUtil.isMobile(value);
        }
        if (StringUtils.isEmpty(value)) {
            return true;
        }
        return ValidatorUtil.isMobile(value);
    }
}