Sorting ResultSet obtained from SpringJpa ExampleMatcher from most matching to least to be used in an Advanced Search - mysql

Question

I am in the process of writing an advanced search function using Spring boot and MySQL for a Book Management system.
My Book object contains various information such as material id,book name, author, publisher, description, product type (as in a story book or a reference material etc.)
I managed to write an ExampleMatcher as follows;
ExampleMatcher exampleMatcher = ExampleMatcher.matchingAny().
withIgnoreCase()
.withIgnorePaths("material_id")
.withStringMatcher(ExampleMatcher.StringMatcher.CONTAINING)
.withStringMatcher(ExampleMatcher.StringMatcher.STARTING)
.withIgnoreNullValues();
Example example = Example.of(book, exampleMatcher);
List<Book> all = bookRepository.findAll(example);
But when i get the results set, the results are sorted according to the material id. And records that have attributes matching almost all the fields are also there, but sorted according to the id.
Is there a way for me to sort the results in a way that the most matching records are in the first few records in the list and then the other records? As in, to sort from most matching to least matching?
As far as i understood, JpaSort allows ascending and descending sorting and also we can allow specific sorting for specific attributes.
But in the advanced search, the searching is done dynamically according to the attributes that the user fills in. Therefore, i cannot program which fields of the table to sort right? For example, if i program the book name field to be sorted in ascending order and if the user did not specify any value for that particular field, then sorting under that field is useless right?
That is why i want to know if there is any way to dynamically sort the results from most matching to least matching. Any way of achieving this task is much appreciated. Thank you.

Answer 1

After two whole days of reading more than 50-70 articles and posts on the Internet, i was able to implement the Advanced Search in a more optimized manner.
I was not able to find how to sort the results obtained from most-matching to least-matching as i originally asked in the question. So if someone can still answer my original question, i am happy to accept.
The workaround i used is as follows.
From an idea i got to dynamically generate the SQL query, i was able to find a lead and referred articles on that.
In Dynamic Query in Spring Boot, the author has used Java Reflection API to manually go through the non-null fields of the entity class and to generate the SQL query. But as we all know, when you are using Springboot and when all the configurations are done for you by Springboot, i don't think it is really an effective way to have the Hibernate dependency explicitly, to manage sessions and run your SQL query. The HibernateJpaSessionFactoryBean used in the above article is now deprecated. Therefore, i referred various articles and the Spring Data Jpa Documentation but could not resolve the error that i always got saying that Springboot cannot find the entityManagerFactory bean.
Therefore, i searched for ways to dynamically generate queries using Spring Data JPA itself and not use Hibernate and facing a hassle on session managing etc. Dynamic Queries with Spring Data JPA Specifications and Using Spring Data JPA Specification has enough information on how to implement JpaSpecification in order to generate queries dynamically in Springboot.
So at the end, i used information from all these 3 articles sited here to come up with my implementation. I used Java Reflection to create the Specification according to the Class type of the non-null fields in my entity object.
The new part i added by myself was, i grouped all the separate Specifications together to a List, and wrote a loop to dynamically generate the final Specification to be used in retrieving the data. It is as follows.
List<BookSpecification> bookSpecifications = createDynamicQuery(book);
if (bookSpecifications.size() != 0) {
Specification<Book> dynamicQuery = Specification.where(bookSpecifications.get(0));
for (int i = 1; i < bookSpecifications.size(); i++) {
dynamicQuery = dynamicQuery.or(bookSpecifications.get(i));
}
List<Book> all = bookRepository.findAll(dynamicQuery);
all.forEach(System.out::println);
return all;
}
The createDynamicQuery() method above, which i used in my own way is inspired from the information in the cited articles.
Using this way, i was able to obtain much more accurate Advanced Search results rather than using ExampleMatcher for the same advanced search criteria. And since i am searching by specific field names, the search results were also sorted in an accurate way.