0
我是使用spring boot + jersey api + JPA的新人。 我有三个使用一对多双向映射的实体。当我使用spring boot + jersey api + JPA时我收到错误： failed to lazily initialize a collection of role: com.kavinaam.GSTbilling.entity.Country.states, could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->com.kavinaam.GSTbilling.entity.City["states"]->com.kavinaam.GSTbilling.entity.States["countyId"]->com.kavinaam.GSTbilling.entity.Country["states"])Spring boot + jersey api + JPA：未能懒洋洋地初始化角色集合
我已经添加了我的实体，道，服务和终点。
@Entity
@Table(name="country")
public class Country implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id")
private int id;
@Column(name="countryName")
private String countryName;
@OneToMany(mappedBy = "countyId",cascade = CascadeType.ALL)
private Set<States> states;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCountryName() {
return countryName;
}
public void setCountryName(String countryName) {
this.countryName = countryName;
}
public Set<States> getStates() {
return states;
}
public void setStates(Set<States> states) {
this.states = states;
}
}
我的状态类：
@Entity
@Table(name="states")
public class States implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id")
private int id;
@ManyToOne
@JoinColumn(name="countyId")
private Country countyId;
@Column(name="stateName")
private String stateName;
@OneToMany(mappedBy = "states", cascade = CascadeType.ALL)
private Set<City> city;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Country getCountyId() {
return countyId;
}
public void setCountyId(Country countyId) {
this.countyId = countyId;
}
public String getStateName() {
return stateName;
}
public void setStateName(String stateName) {
this.stateName = stateName;
}
public Set<City> getCity() {
return city;
}
public void setCity(Set<City> city) {
this.city = city;
}
}
我的城市类：
@Entity
@Table(name="cities")
public class City implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id")
private int id;
@ManyToOne
@JoinColumn(name="stateId")
private States states;
@Column(name="cityName")
private String cityName;
@Column(name="zip")
private String zip;
public void setId(int id) {
this.id = id;
}
public void setZip(String zip) {
this.zip = zip;
}
public States getStates() {
return states;
}
public void setStates(States states) {
this.states = states;
}
public String getCityName() {
return cityName;
}
public void setCityName(String cityName) {
this.cityName = cityName;
}
public String getZip() {
return zip;
}
public int getId() {
return id;
}
}
吾道：
@Transactional
@Repository
public class GSTCityDAO implements IGSTCityDAO {
@PersistenceContext
private EntityManager entityManager;
//@SuppressWarnings("unchecked")
@Override
public List<City> getAllCities() {
//Session session = sessionFactory.getCurrentSession();
String hql = "FROM City as ct ORDER BY ct.id";
List<City> l = entityManager.createQuery(hql,City.class).getResultList();
return l;
}
@Override
public City getCityById(int cityId) {
return entityManager.find(City.class, cityId);
}
@SuppressWarnings("unchecked")
@Override
public List<City> getCityByStateId(States stateId) {
String getcitybystate = " FROM City as c WHERE c.states = ?";
return (List<City>) entityManager.createQuery(getcitybystate).setParameter(1, stateId).getResultList();
}
@Override
public void addCity(City city) {
entityManager.persist(city);
}
@Override
public void updateCity(City city) {
City cityctl = getCityById(city.getId());
cityctl.setCityName(city.getCityName());
cityctl.setZip(city.getZip());
cityctl.setStates(city.getStates());
entityManager.flush();
}
@Override
public void deleteCity(int cityId) {
entityManager.remove(getCityById(cityId));
}
@Override
public boolean cityExists(String name, String zip) {
String hql = "FROM City WHERE cityName = ? and zip = ?";
int count = entityManager.createQuery(hql).setParameter(1,name).setParameter(2, zip).getResultList().size();
return count > 0 ? true : false;
}
}
服务：
@Service
public class GSTCityService implements IGSTCityService {
@Autowired
private IGSTCityDAO cityDAO;
@Override
public List<City> getAllCities() {
List<City> l = cityDAO.getAllCities();
Hibernate.initialize(l);
return l;
}
public List<City> getCityByStateId(States stateId) {
return cityDAO.getCityByStateId(stateId);
}
@Override
public City getCityById(int cityId) {
City city = cityDAO.getCityById(cityId);
return city;
}
@Override
public synchronized boolean addCity(City city) {
if(cityDAO.cityExists(city.getCityName(), city.getZip())){
return false;
}else{
cityDAO.addCity(city);
return true;
}
}
@Override
public void updateCity(City city) {
cityDAO.updateCity(city);
}
@Override
public void deleteCity(int cityId) {
cityDAO.deleteCity(cityId);
}
}
终点：
@Component
@Path("/")
public class Test {
private static final Logger logger = LoggerFactory.getLogger(Test.class);
@Autowired
private IGSTCityService cityService;
@GET
@Path("/hi")
@Produces(MediaType.APPLICATION_JSON)
public Response hello(){
return Response.ok("Hello GST").build();
}
@GET
@Path("/test")
@Produces(MediaType.APPLICATION_JSON)
public Response getAllDate(){
List<City> list = cityService.getAllCities();
for(City city: list){
System.out.println(city);
}
return Response.ok(list).build();
}
@GET
@Path("/test/{id}")
@Produces(MediaType.APPLICATION_JSON)
public Response getAllDateBySome(@PathParam("id") Integer id){
States state = new States();
state.setId(id);
List<City> list = cityService.getCityByStateId(state);
return Response.ok(list).build();
}
@GET
@Path("/{id}")
@Produces(MediaType.APPLICATION_JSON)
public Response getDataById(@PathParam("id")Integer id){
City citl = cityService.getCityById(id);
return Response.ok(citl).build();
}
@POST
@Path("/add")
@Consumes(MediaType.APPLICATION_JSON)
public Response addData(City city){
boolean isAdded = cityService.addCity(city);
if(!isAdded){
return Response.status(Status.CONFLICT).build();
}
return Response.created(URI.create("/gst/"+ city.getId())).build();
}
@PUT
@Path("/update")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public Response updateCountry(City city){
cityService.updateCity(city);
return Response.ok(city).build();
}
@DELETE
@Path("/{id}")
@Consumes(MediaType.APPLICATION_JSON)
public Response deleteCountry(@PathParam("id")Integer id){
cityService.deleteCity(id);
return Response.noContent().build();
}
}
我使用进口org.springframework.transaction.annotation.Transactional;在DAO中是跨国的。我也不能使用@PersistenceContext（类型= PersistenceContextType.EXTENDED）和提取类型渴望，因为我得到最大堆栈大小的误差超过
在调用哪些方法时发生错误？ –
public response getAllDate（）{ \t \t List list = cityService.getAllCities（）; \t \t（城市：列表）{ \t \t \t System.out.println（city）; \t \t} \t \t return Response.ok（list）.build（）; \t \t} 当它返回Response.ok（list）.build（）时发生错误。 我认为当它要求在浏览器中打印数据时，会话可能会被关闭。 –