Get list of database errors on saveAll() - spring-boot

Question

I have a CountryObject:
#Entity
#Table(name = "country")
class CountryObject(
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", nullable = false)
val id: Long? = null,
#Column(name = "name")
val name: String,
#Column(name = "ISO2", length = 2)
val ISO2: String,
#Column(name = "ISO3", length = 3)
val ISO3: String
) : Serializable
with the corresponding PostgreSQL create script that has some unique constraints on ISO2 and ISO3:
CREATE TABLE country
(
id BIGINT NOT NULL,
name VARCHAR(255) NOT NULL,
iso2 VARCHAR(2) NOT NULL,
iso3 VARCHAR(3) NOT NULL,
CONSTRAINT pk_country PRIMARY KEY (id)
);
ALTER TABLE country
ADD CONSTRAINT UNIQUE_CONSTRAINT_ISO2 UNIQUE (iso2);
ALTER TABLE country
ADD CONSTRAINT UNIQUE_CONSTRAINT_ISO3 UNIQUE (iso3);
Along with this I have a corresponding repository:
#Repository
interface CountryRepository : JpaRepository<CountryObject, Long>
And out of the box implementation of the CountryRepository has a saveAll() method that tries to insert a list of objects into the country table. So far, everything behaves as expected.
Once I try to insert a list that have multiple objects violating the unique constraints, the exception is thrown on the first and stopped. What I want to have is to get some list with the errors that I can use as a report, which mentions which entries failed saving. Of course nothing should be saved in that case and the transaction is rolled back.
Any hints how something like this can me achieved? Of course one option would be to try to save each object separately and then collect the errors, but that might be not that performant.