CODEWITHSUNDEEP
javahibernate
usr-local-ΕΨΗΕΛΩΝ
usr-local-ΕΨΗΕΛΩΝ

Reputation: 26904

Detecting string overlength in advance

I'm using Hibernate to persist data decoded from file inputs. Since one of our format is a variable-length format, I'd like to easily check for possible insertion errors in the entity before the transaction gets committed, so I can handle exceptions and take appropriate actions.

If I have an entity

@Entity
public class Entity {

    @Column(...,length=20)
    private String col1;

    @Column(...,length=20)
    private String col2;

    @Column(...,length=40)
    private String col3;

    ...

    @Column(...,length=100)
    private String col..N;

}

I'd like to detect if the String I set as value of each column is compatible with its length, possibly without instrumenting Java code to validate each and every field against the max length.

Currently, I only get a SQL exception when transaction is committed (i.e. @Transactional method returns) for the whole batch when only a single record is affected by a problem. Catching an exception when I Session.persist(entity) would be appreciable.

Any ideas?

Upvotes: 1

Views: 87

Answers (2)

Predrag Maric
Predrag Maric

Reputation: 24433

Since you already use Hibernate, have you considered Hibernate Validator? It would look something like this

@Size(max = 20)
@Column(...,length=20)
private String col1;

// and validation itself
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
validator = factory.getValidator();
Set<ConstraintViolation<Entity>> constraintViolations = validator.validate(entity);

Downside is that you would have to use another set of annotations beside @Column, but on the other hand it offers much more options.

Another option is to use aspects and intercept every setter for String fields on classes annotated with @Entity. In the aspect you would get the @Column annotation and compare the parameter length with configured lenght attribute n the annotation.

Upvotes: 4

kmandov
kmandov

Reputation: 3209

You can use a custom Interceptor to trim the Strings as suggested here: Properly handling long data in Hibernate

or maybe using the Length annotation and a custom Length validator as suggested here: hibernate validator LengthValidator of truncated string

Upvotes: 0

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