validation参数校验器的使用

1.引入依赖

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

2.在需要校验的参数上加@Valid注解

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

3.在需要检验的参数类里面加注解

@NotNull：参数不能为空 

@Length(min = 32)：参数长度最小32

@IsMobile:这个是我们自定义的参数，在后面进行具体编写

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.自定义一个参数校验器

我们照猫画虎，利用@NotNull这个注解为参考来定义一个自己的校验器。

4.1查看@NotNull的源码

/*
 * 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 复制到我们的校验器里面进行修修改改

里面的IsMobileValidator.class是我们自己的参数校验类，用来定义具体的校验策略。我们在后面会进行编写。

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 {
    /**
     * 默认可以为空
     *
     * @return
     */
    boolean required() default false;

    /**
     * 校验错误的提示信息
     * @return
     */
    String message() default "手机号码格式错误";

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

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


}

4.3定义我们自己的校验类

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
     * 拿到我们的注解
     *
     * @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);
    }
}