Spring Data REST custom query integration - spring

Question

I want to create a REST link for an Employee entity that will basically be a findByAllFields query. Of course this should be combined with Page and Sort. In order to do that I have implemented the following code:
#Entity
public class Employee extends Persistable<Long> {
#Column
private String firstName;
#Column
private String lastName;
#Column
private String age;
#Column
#Temporal(TemporalType.TIMESTAMP)
private Date hiringDate;
}
So I would like to have lets say a query where I can do:
http://localhost:8080/myApp/employees/search/all?firstName=me&lastName=self&ageFrom=20&ageTo=30&hiringDateFrom=12234433235
So I have the following Repository
#RepositoryRestResource(collectionResourceRel="employees", path="employees")
public interface EmployeeRepository extends PagingAndSortingRepository<Employee, Long>,
JpaSpecificationExecutor<Employee> {
}
Ok so now I need a RestController
#RepositoryRestController
public class EmployeeSearchController {
#Autowired
private EmployeeRepository employeRepository;
#RequestMapping(value = "/employees/search/all/search/all", method = RequestMethod.GET)
public Page<Employee> getEmployees(EmployeeCriteria filterCriteria, Pageable pageable) {
//EmployeeSpecification uses CriteriaAPI to form dynamic query with the fields from filterCriteria
Specification<Employee> specification = new EmployeeSpecification(filterCriteria);
return employeeRepository.findAll(specification, pageable);
}
Ok, obviously this does its job but it is not integrated with HATEOAS.
I have attempted to assemble a resource changing the controller to this:
public PagedResources<Resource<Employee>> getEmployees(
PagedResourcesAssembler<Employee> assembler,
EmployeeCriteria filterCriteria, Pageable pageable) {
//EmployeeSpecification uses CriteriaAPI to form dynamic query with the fields from filterCriteria
Specification<Employee> specification = new EmployeeSpecification(filterCriteria);
Page<Employee> employees = employeeRepository.findAll(specification, pageable);
return assembler.toResource(employees);
}
Obviously I'm missing something from the above since it doesnt work and I'm getting the following Exception:
Could not instantiate bean class [org.springframework.data.web.PagedResourcesAssembler]: No default constructor found;
Ok so to make the question clear I am trying to integrate the above resource into the rest of the HATEOAS architecture. I'm not entirely sure if this is the correct approach so any other suggestions are welcome.
EDIT:
Here you can see a similar implementation. Please take a look at the configuration, you will see that all but one of the "Person" controllers are working.
https://github.com/cgeo7/spring-rest-example

Answer 1

Try autowring PagedResourcesAssembler as a class member and change method signature something like below
#RepositoryRestController
public class EmployeeSearchController {
#Autowired
private EmployeeRepository employeRepository;
#Autowired
private PagedResourcesAssembler<Employee> pagedAssembler;
#RequestMapping(value = "/employees/search/all/search/all", method = RequestMethod.GET)
public ResponseEntity<Resources<Resource<Employee>>> getEmployees(EmployeeCriteria filterCriteria, Pageable pageable) {
//EmployeeSpecification uses CriteriaAPI to form dynamic query with the fields from filterCriteria
Specification<Employee> specification = new EmployeeSpecification(filterCriteria);
Page<Employee> employees = employeeRepository.findAll(specification, pageable);
return assembler.toResource(employees);
}
}
This works perfectly with Spring Data Rest 2.1.4.RELEASE

Answer 2

The code by #Stackee007 works but the resource won't include self links. In order to do that, a little more is required.
#Autowired
PagedResourcesAssembler<Appointment> pagedResourcesAssembler;
#RequestMapping(value = "/findTodaysSchedule")
public HttpEntity<PagedResources<Resource<Appointment>>> getTodaysSchedule(
PersistentEntityResourceAssembler entityAssembler, Pageable pageable) {
Page<Appointment> todaysSchedule = apptRepo.findByStartTimeBetween(beginningOfDay, endOfDay, pageable);
#SuppressWarnings({ "unchecked", "rawtypes" })
PagedResources<Resource<Appointment>> resource = pagedResourcesAssembler.toResource(todaysSchedule,
(ResourceAssembler) entityAssembler);
return new ResponseEntity<>(resource, HttpStatus.OK);
}

Answer 3

Spring HATEOAS has changed the name of Resource, PagedResources and some other classes. See here. Below is a working version in 2020.
#RepositoryRestController
public class EmployeeSearchController {
#Autowired
private EmployeeRepository employeRepository;
#Autowired
private PagedResourcesAssembler<Employee> pagedAssembler;
#RequestMapping(value = "/employees/search/all", method = RequestMethod.GET)
public ResponseEntity<PagedModel<EntityModel<Employee>>> getEmployees(PersistentEntityResourceAssembler entityAssembler,,
EmployeeCriteria filterCriteria,
Pageable pageable) {
Specification<Employee> specification = new EmployeeSpecification(filterCriteria);
Page<Employee> employees = employeeRepository.findAll(specification, pageable);
return ResponseEntity.ok(pagedAssembler.toModel(plants, (RepresentationModelAssembler) entityAssembler));
}
}