@Notblank, @notnull, @notempty differences and uses

Through annotation, we can verify the format of parameters more gracefully , But in use @NotEmpty、@NotBlank、@NotNull In the process of ,

Because the meaning is a little similar , So there will be some confusion when using , below , Explain the use of these three annotations one by one ：

@NotNull

For basic data types (Integer,Long,Double wait ), When @NotNull Annotations are used in String Type of data , Then it means that the data cannot be Null（ But it can be for Empty）

@NotBlank

Apply to String Type of data , added @NotBlank The parameter of annotation cannot be Null And trim() after size > 0

@NotEmpty

Apply to String、Collection aggregate 、Map、 Array wait , added @NotEmpty The parameter of annotation cannot be Null perhaps The length is 0

When using these annotations , One more thing to note , That is in Controller When defining methods at layer Add @Valid perhaps @Validated annotation , Otherwise, the annotation will be invalid , Here's the picture ：

End of the flower ~

Reference link ：https://blog.csdn.net/yangchao1125/article/details/107323177/