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How do I filter data in a restful way using Spring?

As the title says.

I basically would love to do requests like

/api/todos/?completed=eq.true&created_at=lt.1486462109399

Is there any ready spring way of achieving such? Something akin to the Page/Pageable mechanism would be great.

If there is none I think I could implement it using Hibernate Criteria Queries & Argument Re-solvers. Basically allowing me to write my controllers like

 @GetMapping
 public ResponseEntity<Page<TodoDTO>> listAll(Criteria criteria, Pageable pageable) 
 {
        Page<Todo> todos = todoService.listAll(criteria, pageable)
        ...
 }

A custom Argument resolver would be responsible for turning the query string into a Criteria. Not quite sure yet how I would handle it within the service but that’s the direction in which I would try to implement this.

Would that be a good approach? Any recommendations? (All assuming there are no ready mechanism for such already).

Your help is much appreciated.

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Answer

Another option to build a fluent query API is to use a RSQL parser. RSQL is a query language for parametrized filtering of entries in RESTful APIs. Follow this article and your API would be able to handle URLs like:

http://localhost:8080/users?search=firstName==jo*;age<25

Sample controller:

@RestController
@RequestMapping(value = "/users")
public class UserController {

    @Autowired
    private UserRepository repo;

    @GetMapping
    public List<User> findAllByRsql(@RequestParam(value = "search") String search) {
        Node rootNode = new RSQLParser().parse(search);
        Specification<User> spec = rootNode.accept(new CustomRsqlVisitor<User>());
        return repo.findAll(spec);
    }

}

Gradle dependency:

// https://mvnrepository.com/artifact/cz.jirutka.rsql/rsql-parser
implementation("cz.jirutka.rsql:rsql-parser:2.1.0")

Recommendations from the library author:

I recommend to use separate URI query parameter for sorting, e.g. ?query=name==Flynn&sortBy=name, not to mix it with RSQL expression. The same applies to paging; I recommend URI parameters named limit and offset.

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