首先讲到应用场景，当我们前端传送数据到后端控制器中时，将Json数据转换为javabean对象，这时我们需要对封装的属性数据进行检验，以避免获取到不合理的数据。

JAVA validation 验证List javax.validation.validation_正则表达式

这里通过封装好的工具类ValidatorUtils进行校验，稍后贴出该工具类分析结构，在这之前我们要保证javabean属性添加了相应的注解，通过注解可以完成相应功能的校验了。常用的注解如下（validation-api-2.0.1.Final.jar）：

注解

适用的类型

功能

@AssertFalse

Boolean, boolean

验证注解的元素值是false

@AssertTrue

Boolean, boolean

验证注解的元素值是true

@DecimalMax（value=x）

BigDecimal, BigInteger, String, byte,short, int, long and the respective wrappers of the primitive types. Additionally supported by HV: any sub-type of Number andCharSequence.

验证注解的元素值小于等于@ DecimalMax指定的value值

@DecimalMin（value=x）

BigDecimal, BigInteger, String, byte,short, int, long and the respective wrappers of the primitive types. Additionally supported by HV: any sub-type of Number andCharSequence

验证注解的元素值大于等于@ DecimalMin指定的value值

@Digits(integer=整数位数, fraction=小数位数)

BigDecimal, BigInteger, String, byte,short, int, long and the respective wrappers of the primitive types. Additionally supported by HV: any sub-type of Number andCharSequence.

验证注解的元素值的整数位数和小数位数上限

@Future

java.util.Date, java.util.Calendar; Additionally supported by HV, if theJoda Time date/time API is on the class path: any implementations ofReadablePartial andReadableInstant.

验证注解的元素值（日期类型）比当前时间晚

@Max（value=x）

BigDecimal, BigInteger, byte, short,int, long and the respective wrappers of the primitive types. Additionally supported by HV: any sub-type ofCharSequence (the numeric value represented by the character sequence is evaluated), any sub-type of Number.

验证注解的元素值小于等于@Max指定的value值

@Min（value=x）

BigDecimal, BigInteger, byte, short,int, long and the respective wrappers of the primitive types. Additionally supported by HV: any sub-type of CharSequence (the numeric value represented by the char sequence is evaluated), any sub-type of Number.

验证注解的元素值大于等于@Min指定的value值

@NotNull

Any type

验证注解的元素值不是null

@Null

Any type

验证注解的元素值是null

@NotEmpty

CharSequence,Collection, Map and Arrays

验证注解的元素值不为null且不为空（字符串长度不为0、集合大小不为0）

@NotBlank

CharSequence

验证注解的元素值不为空（不为null、去除首位空格后长度为0），不同于@NotEmpty，@NotBlank只应用于字符串且在比较时会去除字符串的空格

@Past

java.util.Date, java.util.Calendar; Additionally supported by HV, if theJoda Time date/time API is on the class path: any implementations ofReadablePartial andReadableInstant.

验证注解的元素值（日期类型）比当前时间早

@Pattern(regex=正则表达式, flag=)

String. Additionally supported by HV: any sub-type of CharSequence.

验证注解的元素值与指定的正则表达式匹配

@Size(min=最小值, max=最大值)

String, Collection, Map and arrays. Additionally supported by HV: any sub-type of CharSequence.

验证注解的元素值的在min和max（包含）指定区间之内，如字符长度、集合大小

@Valid

Any non-primitive type（引用类型）

验证关联的对象，如账户对象里有一个订单对象，指定验证订单对象

@Range(min=最小值, max=最大值)

CharSequence, Collection, Map and Arrays,BigDecimal, BigInteger, CharSequence, byte, short, int, long and the respective wrappers of the primitive types

验证注解的元素值在最小值和最大值之间

@Length(min=下限, max=上限)

CharSequence

验证注解的元素值长度在min和max区间内

@Email

CharSequence

验证注解的元素值是Email，也可以通过正则表达式和flag指定自定义的email格式

 

 

public class ValidatorUtils {
    private static Validator validator;

    static {
        validator = Validation.buildDefaultValidatorFactory().getValidator();
    }

    /**
     * 校验对象
     * @param object        待校验对象
     * @param groups        待校验的组
     * @throws MyException  校验不通过，则报MyException异常
     */
    public static void validateEntity(Object object, Class<?>... groups)
            throws MyException {
        Set<ConstraintViolation<Object>> constraintViolations = validator.validate(object, groups);
        if (!constraintViolations.isEmpty()) {
            List<String> collect = constraintViolations.stream().map(constant -> constant.getMessage()).collect(Collectors.toList());
            String msg = StringUtils.join(collect, ",");
            throw new MyException(msg);
        }
    }
}