JPA：在@Query 中使用 AttributeConverter

Question

I wrote my own AttributeConverter to encrypt and decrypt ByteArrays based on thoughts-on-java and looks similar to:

@Converter
public class CryptoByteArrayConverter implements AttributeConverter < Byte[], Byte[] > {

    /**
     * {@inheritDoc}
     */
    @Override
    public Byte[] convertToDatabaseColumn(Byte[] attribute) {
        //...works fine
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Byte[] convertToEntityAttribute(Byte[] dbData) {
        //...works also fine
    }
}

My entity class is using this converter:

@Entity
public class ArchivedInvoice implements Serializable {
//...
    @Convert(converter=CryptoByteArrayConverter.class)
    @JsonIgnore
    private Byte[] encryptedXml;
//...
}

Everything works fine until here. The data I had set is encrypted in the database and is also decrypted after getting the result set. But the CryptoByteArrayConverter is not used in @Query automatically. Is it possible to activate it or is there another good workaround?

For example:

@Query("SELECT ai FROM #{#entityName} ai WHERE (ai.encryptedXml = :xml)")
Page < ArchivedInvoice > findByXml(@Param("xml") byte[] xml, Pageable p);

Answer 1

I make it run and realized that it is not needed to check if the decrypted values are equal or not. A comparison of the encrypted value of the DB attribute and the encrypted parameter returns the correct results. After changing the parameter type from byte[] to Byte[] the AttributeConverter has been activated automatically and encrypted the parameter (xml):

@Query("SELECT ai FROM #{#entityName} ai WHERE (ai.encryptedXml = :xml)")
Page < ArchivedInvoice > findByXml(@Param("xml") Byte[] xml, Pageable p);

The following test shows what I mean:

@Test
public void saveTestEncryption() throws UnsupportedEncodingException {
    repository.deleteAll();
    ArchivedInvoice arcInv = createDTO(0);
    repository.save(arcInv);
    assertEquals(1, repository.count());
    PageRequest pageRequest = new PageRequest(0, 25);
    //Not encrypted!
    String xml = arcInv.getXml();
    Page < ArchivedInvoice > list =
            repository.findByXml(ByteUtils.convert(xml.getBytes("UTF-8")), pageRequest);
    assertEquals(1, list.getTotalElements());
    xml += "A";
    list = repository.findByXml(ByteUtils.convert(xml.getBytes("UTF-8")), pageRequest);
    assertEquals(0, list.getTotalElements());
}