Catch duplicate entry Exception

I use spring so we resolve it by org.springframework.dao.DataIntegrityViolationException

try {
    ao_history_repository.save(new AoHistory(..));
} catch (DataIntegrityViolationException e) {
    System.out.println("history already exist");
}

But as @KevinGuancheDarias mention it:

Please note that while this works. I suggest to solve the problem by issuing a findBy before the save, as this is messy, and I think it's not warranted that it will work in future versions, may even break without notification.

vendorCode 2601 is for unique index constraint violate so you can check SQLException cewndorCode by e.getErrorCode() == 2601. sample code:

try {
    ao_history_repository.save(new AoHistory(..));
} catch (SQLException e) {
    if (e.getErrorCode() == 2601) {
        System.out.println("handle duplicate index error here!");
    } else {
        System.out.println("handle other error code here!");
    }
}

I use Spring. So catch org.springframework.dao.DuplicateKeyException

try{
    ...
} catch (DuplicateKeyException dke) {
    ...
} 

catch SQLIntegrityConstraintViolationException, if you are using Java 1.6+

e.g.

try {
    ps.executeUpdate("INSERT INTO ...");
} catch (SQLIntegrityConstraintViolationException e) {
    // Duplicate entry
} catch (SQLException e) {
    // Other SQL Exception
}

or

try {
    ps.executeUpdate("INSERT INTO ...");
} catch (SQLException e) {
    if (e instanceof SQLIntegrityConstraintViolationException) {
        // Duplicate entry
    } else {
        // Other SQL Exception
    }
}