spring - 一种定向建模在使用Spring Data Redis时不拉取记录

Question

我正在开发 Spring Boot + Spring Data Redis 示例。在此示例中 - 我以嵌套方式对 redis 进行了建模。当我只是提取部门详细信息时，我一无所获。怎么解决这个问题？

错误:

org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [com.example.model.Employee] to type [com.example.model.Department]
    at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:321)
    at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:194)
    at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:174)
    at org.springframework.data.repository.query.ResultProcessor$ProjectingConverter.convert(ResultProcessor.java:293)
    at org.springframework.data.repository.query.ResultProcessor$ChainingConverter.lambda$and$0(ResultProcessor.java:213)
    at org.springframework.data.repository.query.ResultProcessor$ChainingConverter.convert(ResultProcessor.java:224)
    at org.springframework.data.repository.query.ResultProcessor.processResult(ResultProcessor.java:152)
    at org.springframework.data.repository.query.ResultProcessor.processResult(ResultProcessor.java:119)
    at org.springframework.data.keyvalue.repository.query.KeyValuePartTreeQuery.execute(KeyValuePartTreeQuery.java:109)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:602)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:590)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at 

员工.java

@RedisHash("employees")
public class Employee {
    @Id @Indexed
    private String id;
    private String firstName;
    private String lastName;
    private List<Address> addresses;

    private List<Department> departments;
}

部门.java

@RedisHash("departments")
public class Department {
    @Id
    private String id;
    @Indexed
    private String departmentName;
    private List<Project> projects;
}

项目.java

public class Project {
    @Indexed
    private String projectName;
    @Indexed
    private String projectCategory;
}

EmployeeRepository.java

public interface EmployeeRepository extends CrudRepository<Employee, String>{

    List<Employee> findByAddresses_Street(String street);

    List<Employee> findByAddresses_City(String city);

    List<Employee> findByDepartments_Projects_ProjectCategory(String category);


    List<Department> findByDepartments_DepartmentName(String departmentNames);
}

EmployeeDeparmentProjectsTest.java

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class EmployeeDeparmentProjectsTest extends RepositoryTestSupport{
    @Autowired private EmployeeRepository employeeRepository;
    @Autowired private DepartmentsRepository departmentsRepository;

    //@Before
    public void setUp() throws JsonProcessingException {
        Address home = Address.builder().street("ABC Street").city("Pune").build();
        Address offc = Address.builder().street("XYZ Street").city("Pune").build();

        // Projects
        Project linkedIn = Project.builder().projectName("Linked-in").projectCategory("Social").build();
        Project stack = Project.builder().projectName("StackOverFlow").projectCategory("Developer-Social").build();
        Project electrical = Project.builder().projectName("Electrical").projectCategory("Electric").build();
        Project mechanical = Project.builder().projectName("Mechanical").projectCategory("Machines").build();

        Project ml = Project.builder().projectName("ML").projectCategory("Social").build();

        // Departments
        Department ai = Department.builder().departmentName("AI").projects(Arrays.asList(linkedIn, stack)).build();
        Department nonAI = Department.builder().departmentName("NON-AI").projects(Arrays.asList(electrical, mechanical)).build();
        Department dml = Department.builder().departmentName("ML").projects(Arrays.asList(ml)).build();

        // Employee Details
        Employee raj = Employee.builder().firstName("Raj").lastName("Kumar")
                .addresses(Arrays.asList(home, offc))
                .departments(Arrays.asList(ai, nonAI)).build();

        Employee john = Employee.builder().firstName("John").lastName("Doe")
                .addresses(Arrays.asList(home, offc))
                .departments(Arrays.asList(dml)).build();


        employeeRepository.save(raj);
        employeeRepository.save(john);

        List<Employee> employees = employeeRepository.findByAddresses_Street("XYZ Street");
        System.out.println("EMPLOYEE = "+employees);
    }

    @Test
    public void test() {
        List<Employee> employees = employeeRepository.findByDepartments_Projects_ProjectCategory("Social");
        System.out.println("EMployees : "+employees);


        List<Department> departments = departmentsRepository.findByDepartmentName("AI");
        System.out.println("Departments = "+departments);

        List<Department> myDepartments = employeeRepository.findByDepartments_DepartmentName("AI");
        System.out.println("DEPARTMENT SIZE ? ="+myDepartments.size());
        System.out.println("DEPARTMENTS = "+myDepartments);
    }
}

?

Answer 1

由于关系被定义为嵌套。下面的命令将不起作用

List<Department> findByDepartments_DepartmentName(String departmentNames);

获取数据的方法

List<Employee> employees_1 = employeeRepository.findByDepartments_DepartmentName("AI");

// Get Departments
List<Department> list = new ArrayList<>();
for (Employee employee : employees_1) {
    System.out.println("EMP ? = "+employee.getDepartments());
    list.addAll(employee.getDepartments());
}
System.out.println(list);