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我正在为我的数据库开发一个宁静的Web服务。我正在使用jpa从数据库和弹簧中为该体系结构重新获取数据。我已经用基本的dao查询（findById，save ...）测试了这个体系结构，并且它完美地工作。然后，在DAO实现我增加了一个新方法至极基本上执行被直接测试的MySQL数据库的查询（和它的工作）未能懒洋洋地初始化集合
public List<PositionHistory> findByFavUserGBuser(Integer favoriteUserId,
Integer pageNumber, Integer rowsPerPage, String usernameFilter) {
String queryString="" +
"SELECT ph.* " +
"FROM user u, position_history ph, spot s " +
"WHERE " +
"ph.date IN (SELECT MAX(ph2.date) FROM position_history ph2 GROUP BY ph2.user_iduser) and " +
"s.id_spot=ph.spot_idspot and " +
"u.id_user=ph.user_iduser and ";
if (usernameFilter!=null)
queryString+="u.username like '%:usernameFilter%' and ";
queryString+="" +
"ph.user_iduser IN (SELECT ALL fu.user_iduserto FROM favorite_user fu WHERE fu.user_iduserfrom=:favoriteUserId) " +
"GROUP BY ph.user_iduser " +
"LIMIT :startLimit,:rowsPerPage";
Query query = entityManager.createNativeQuery(queryString,PositionHistory.class);
query.setParameter("favoriteUserId", favoriteUserId);
query.setParameter("startLimit", pageNumber*rowsPerPage);
query.setParameter("rowsPerPage", rowsPerPage);
if (usernameFilter!=null)
query.setParameter("usernameFilter", usernameFilter);
return query.getResultList();
}
，然后我创建了一个控制器以检索数据如下：
@Controller
@Transactional
public class MyController {
@Autowired
public DaoPositionHistory dph;
@Transactional
@RequestMapping(value = "/getData/{id}/", method = RequestMethod.POST)
@ResponseBody
public List<PositionHistory> home(@PathVariable int id) {
List<PositionHistory> resultlist=(List<PositionHistory>) dph.findByNearestPositionGBuser(id, 0, 10, null, null, null);
return resultlist;
}
}
但是当我拨打服务我得到以下错误：
ERROR: org.hibernate.LazyInitializationException - failed to lazily initialize a collection of role: com.windy.spring.data.User.favoriteSports, no session or session was closed
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.windy.spring.data.User.favoriteSports, no session or session was closed
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383)
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:368)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:111)
at org.hibernate.collection.PersistentBag.iterator(PersistentBag.java:272)
at org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:45)
at org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:23)
at org.codehaus.jackson.map.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:86)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446)
at org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446)
at org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112)
at org.codehaus.jackson.map.ser.std.StdContainerSerializers$IndexedListSerializer.serializeContents(StdContainerSerializers.java:122)
at org.codehaus.jackson.map.ser.std.StdContainerSerializers$IndexedListSerializer.serializeContents(StdContainerSerializers.java:71)
at org.codehaus.jackson.map.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:86)
at org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:610)
at org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:256)
at org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1613)
at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:142)
at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:179)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:137)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:81)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:94)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:73)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
我不明白为什么我得到这个错误，如果我宣布methos为@Transactional？有关我如何解决问题的任何想法？
这里也是我的用户类
@XmlRootElement
@Entity
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id_user")
private int idUser;
private String cellphone;
private String email;
@Lob()
private byte[] foto;
private String name;
private String notes;
private String password;
private String surname;
private String username;
//bi-directional many-to-one association to FavoriteSport
@OneToMany(mappedBy="user")
private List<FavoriteSport> favoriteSports;
//bi-directional many-to-one association to FavoriteSpot
@OneToMany(mappedBy="user")
private List<FavoriteSpot> favoriteSpots;
//bi-directional many-to-one association to FavoriteUser
@OneToMany(mappedBy="user2")
private List<FavoriteUser> favoriteUsers;
//uni-directional many-to-one association to Role
@ManyToOne
@JoinColumn(name="role_idrole")
private Role role;
//bi-directional many-to-one association to UserAccount
@OneToMany(mappedBy="user")
private List<UserAccount> userAccounts;
public User() {
}
public int getIdUser() {
return this.idUser;
}
public void setIdUser(int idUser) {
this.idUser = idUser;
}
public String getCellphone() {
return this.cellphone;
}
public void setCellphone(String cellphone) {
this.cellphone = cellphone;
}
public String getEmail() {
return this.email;
}
public void setEmail(String email) {
this.email = email;
}
public byte[] getFoto() {
return this.foto;
}
public void setFoto(byte[] foto) {
this.foto = foto;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public String getNotes() {
return this.notes;
}
public void setNotes(String notes) {
this.notes = notes;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
public String getSurname() {
return this.surname;
}
public void setSurname(String surname) {
this.surname = surname;
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public List<FavoriteSport> getFavoriteSports() {
return this.favoriteSports;
}
public void setFavoriteSports(List<FavoriteSport> favoriteSports) {
this.favoriteSports = favoriteSports;
}
public List<FavoriteSpot> getFavoriteSpots() {
return this.favoriteSpots;
}
public void setFavoriteSpots(List<FavoriteSpot> favoriteSpots) {
this.favoriteSpots = favoriteSpots;
}
public List<FavoriteUser> getFavoriteUsers() {
return this.favoriteUsers;
}
public void setFavoriteUsers(List<FavoriteUser> favoriteUsers) {
this.favoriteUsers = favoriteUsers;
}
public Role getRole() {
return this.role;
}
public void setRole(Role role) {
this.role = role;
}
public List<UserAccount> getUserAccounts() {
return this.userAccounts;
}
public void setUserAccounts(List<UserAccount> userAccounts) {
this.userAccounts = userAccounts;
}
}