Question

我正在使用Spring restful api和hibernate。我使用两个名为Employee和Second的实体类从两个表中获取数据。我想在两个表的列表中得到结果，并希望在单个json对象中返回它。

这是我的DAO课程

// Method to get the result from employee table
@SuppressWarnings("unchecked")
public List<Employee> getEntityList() throws Exception {
session = sessionFactory.openSession();
    tx = session.beginTransaction();
    List<Employee> employeeList = session.createCriteria(Employee.class)
            .list();
tx.commit();
    session.close();
    return employeeList;
}

// Method to get the result from second table
@SuppressWarnings("unchecked")
public List<Second> getSecondList() throws Exception {
session = sessionFactory.openSession();
    tx = session.beginTransaction();
    List<Second> secondList = session.createCriteria(Second.class)
            .list();
    tx.commit();
    session.close();
    return secondList;
}

我的服务类

@Autowired
DataDao dataDao;
public List<Employee> getEntityList() throws Exception {
    return dataDao.getEntityList();
}

public List<Second> getSecondList() throws Exception {
    return dataDao.getSecondList();
}

这是我的RestController

@RequestMapping(value = "/list", method = RequestMethod.GET)
public @ResponseBody
List<Employee> getEmployee() {
    List<Employee> employeeList = null;
    try {
            employeeList = dataServices.getEntityList();
    } catch (Exception e) {
            e.printStackTrace();
    }
    return employeeList;
}

这里的数据只来自一个表员工，但我也希望从第二个表中获取数据，并希望在employeeList中返回该数据。 w ^

我该怎么办请建议我。 Thanx提前

Answer 1

我想你可能需要这样的例子

@RestController

public class EmployeeRestController {


    @RequestMapping(value = "/employees")
    public Wrapper getEmployees() {

        Wrapper wrapper = getWrapper();
        return wrapper;

    }

    public Wrapper getWrapper() {
        Wrapper wrapper = new Wrapper();
        List<Employee> employees = getEmployee();
        List<Organizations> organizations = getOrg();

        wrapper.setEmployees(employees);
        wrapper.setOrganizations(organizations);

        return wrapper;
    }

    public List<Employee> getEmployee() {
        Employee employee1 = new Employee(101, "abc", "abc", "SE");
        Employee employee2 = new Employee(102, "def", "def", "SE");
        Employee employee3 = new Employee(103, "xyz", "xyz", "SE");

        List<Employee> employees = new ArrayList<Employee>();


        employees.add(employee1);
        employees.add(employee2);
        employees.add(employee3);

        return employees;
    }

    public List<Organizations> getOrg() {

        Organizations organizations1 = new Organizations();
        organizations1.setName("Google");
        Organizations organizations2 = new Organizations();
        organizations2.setName("Facebook");
        Organizations organizations3 = new Organizations();
        organizations3.setName("Apple");

        List<Organizations> organizations = new ArrayList<Organizations>();
        organizations.add(organizations1);
        organizations.add(organizations2);
        organizations.add(organizations3);

        return organizations;

    }
}


public class Wrapper {

    private List<Employee> employees;
    private List<Organizations> organizations;
    public List<Employee> getEmployees() {
        return employees;
    }
    public void setEmployees(List<Employee> employees) {
        this.employees = employees;
    }
    public List<Organizations> getOrganizations() {
        return organizations;
    }
    public void setOrganizations(List<Organizations> organizations) {
        this.organizations = organizations;
    }
}

这里的Organization和Employee是两个bean类，它们被设置在包装类中。

因此，在您的情况下，您从两个表中获取这两个不同的对象，并将它们包装在一个Wrapper类中并将其发回。

我希望这可以帮到你!!

Answer 2

@java开发者。

问题是您无法将查询输出收集为单个提取。您需要创建一个单独的值对象类，它迭代地映射到两个查询的结果。

然后，您需要将此值对象类映射为spring rest API的返回类型。示例示例如下所示：客户端类正在从两个不同的表组成配置文件和顾问。另请注意parseClientSpreadsheet方法如何设置clientprofiles和clientadvisors。

public class Client extends ReportModel {

    private static final long serialVersionUID = 2292996835674522338L;
    private ClientProfile profile;
    private List<Advisor> advisor;

    public ClientProfile getProfile() {
        return profile;
    }
    public void setProfile(ClientProfile profile) {
        this.profile = profile;
    }
    public List<Advisor> getAdvisor() {
        return advisor;
    }
    public void setAdvisor(List<Advisor> advisor) {
        this.advisor = advisor;
    }
}


@RequestMapping(method = RequestMethod.GET, value = "/list")
    public List<Client> getClients() {

        List<Client> clients;

        // Call the client service and load client data from the database and
        // return the list of clients.
        try {           
            clients = clientService.getClients();           
        } catch (Exception e) {
            file_error_logger.error("Exception while reading clients", e);
            throw e;
        }

        if (logger.isDebugEnabled()) logger.debug("Get client details successful.");

        return clients;
    }

public List<Client> parseClientSpreadsheet(String clientDetailsFilePath,
        int numberOfSheets) throws ClientDataNotFoundException {

    List<Client> clientList = new ArrayList<Client>();

        // if the row is valid, parse the data
        if (isValidRow(row, lastColumn,
                ClientDataConstants.CLIENT_REQUIRED_COLUMNS)) {
            ClientProfile clientProfile;
            List<Advisor> advisorList = new ArrayList<Advisor>();
            Client client = new Client();

            // Set client profile object values
            clientProfile = setClientProfileObject(row);

            // set Advisor list
            advisorList = setAdvisorList(row, lastColumn);

            // set Client object
            String[] additionalRecipients = row
                    .getCell(
                            Integer.parseInt(reportMailerConfigurationService
                                    .getPropertyValue(ClientDataConstants.ADDITIONAL_RECIPIENTS_CELLNUMBER)))
                    .toString().split(";");

            List<String> additionalRecipientsList = new ArrayList<String>();

            // max 4 additional recipients are allowed. So if more are
            // found, take 4 in array and ignore the rest
            for (int i = 0; i < additionalRecipients.length; i++) {
                if (!additionalRecipients[i].isEmpty()) {
                    additionalRecipientsList.add(additionalRecipients[i]);
                    if (additionalRecipientsList.size() == 4) {
                        break;
                    }
                }
            }

            client.setProfile(clientProfile);
            client.setAdvisor(advisorList);
            client.setadditional_recipients(additionalRecipientsList);

            // add the client in the collection
            clientList.add(client);
        } 
    }
    return clientList;
}

如何使用spring rest api从hibernate中的两个表中获取数据，并将单个对象返回到url

2 个答案: