Java field validation collecting error messages

import java.util.LinkedHashMap;
import java.util.Map;

public final class Validator {
    public static Map<String, String> validate(Map<String, String> input) {
        Map<String, String> errors = new LinkedHashMap<>();
        String email = input.get("email");
        if (email == null || email.isBlank()) errors.put("email", "is required");
        else if (!email.contains("@")) errors.put("email", "must contain @");
        String age = input.get("age");
        if (age == null || age.isBlank()) errors.put("age", "is required");
        else {
            try {
                if (Integer.parseInt(age.trim()) < 18) errors.put("age", "must be at least 18");
            } catch (NumberFormatException e) {
                errors.put("age", "must be a number");
            }
        }
        return errors;
    }
}