[HV000030: No validator could be found for constraint 'javax.validation.constraints.NotEmpty' validating type 'java.lang.String'

I got a similiar error but ...Constraints.NotEmpty' validating type 'java.lang.Long'

It happened because I was using @NotEmpty in a non-String field.

I solved it replacing @NotEmpty with @Size(value=1, message= "whatever")

I have the same problem; my spring-boot-starter-web dependency includes a dependency on org.hibernate:hibernate-validator:5.3.6.Final but I. I added this exclusion to my POM and it's all all good now:

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-validator</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
</dependencyManagement>

1. @NotBlank : Checks that the annotated character sequence is not null and the trimmed length is greater than 0.
2. @NotNull : Checks whether the annotated element is not null nor empty.
3. @NotEmpty : Checks that the annotated value is not null

Before use the above annotation, have to think about how it works.

for further reading use this article : Read more article one Read more article two