Spring Data REST自定义查询集成

Question

我想为一个名为Employee的实体创建一个REST链接，它将基本上是一个findByAllFields查询。当然，这应该与Page和Sort相结合。为了做到这一点，我已经实现了以下代码：

@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;
}

所以我想要一个查询，例如我可以执行：

http://localhost:8080/myApp/employees/search/all?firstName=me&lastName=self&ageFrom=20&ageTo=30&hiringDateFrom=12234433235

所以我有以下 Repository

 @RepositoryRestResource(collectionResourceRel="employees", path="employees")
 public interface EmployeeRepository extends PagingAndSortingRepository<Employee, Long>, 
                                                         JpaSpecificationExecutor<Employee> {

 }

好的，现在我需要一个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);
}

好的，显然这个功能可以实现，但它没有与HATEOAS集成。 我尝试重新组装资源将控制器更改为以下内容:

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);
}

显然，从上面的内容来看我漏掉了什么，因为它没有起作用，我得到了以下异常：

Could not instantiate bean class [org.springframework.data.web.PagedResourcesAssembler]: No default constructor found;

好的，为了让问题更清晰，我正在尝试将上述资源集成到HATEOAS架构的其余部分中。我不确定这是否是正确的方法，所以欢迎任何其他建议。

编辑： 在这里，您可以看到类似的实现。请查看配置，您会发现除了一个“Person”控制器之外，其他所有控制器都在工作。 https://github.com/cgeo7/spring-rest-example

- ChrisGeo

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如果您能为您的问题创建一个简单的Github项目，那么更容易找到您的问题...因为没有足够的信息-您的配置、依赖关系等。 - Jama A.

抱歉耽搁了。我创建了一个类似的小项目，反映了我所遇到的所有困难 https://github.com/cgeo7/spring-rest-example - ChrisGeo

@ChrisGeo和@Stackee007，你们介意我问一下你们如何定义你们的“EmployeeCriteria”和“EmployeeSpecification”类吗？请注意，我的翻译尽量通俗易懂，但不改变原意。 - BalRog

Answer 1

尝试将PagedResourcesAssembler作为类成员进行自动装配，并将方法签名更改为以下内容：

@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);
    }
}

这在Spring Data Rest 2.1.4.RELEASE中完美地运作。

- Stackee007

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请参见https://dev59.com/DFwZ5IYBdhLWcg3wLdsF。 - user41871

汇编变量未定义！！为什么？ - Ivan Smorodin

@IvanSmorodin 应该是 pagedAssembler。 - mustofa.id

Answer 2

@Stackee007的代码可以运行，但是资源中不包括self链接。为了实现这一点，需要做更多的工作。

@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);
}

- Abhijit Sarkar

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感谢您提供的进一步说明。这个很好用！ - Jon

Answer 3

Spring HATEOAS已更改了Resource、PagedResources和其他一些类的名称。请参见此处。以下是2020年的工作版本。

@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));
    }
}

- Lala La