我仍然得到异常lazyinitializationexception。 是的,我知道这意味着会话在我或其他人试图访问该集合时关闭。 不,OpenEntityManagerInViewFilter不起作用。 是的,@ ManyToOne(fetch = FetchType.EAGER)有所帮助,但我不想使用它,因为它会一直无法用到它。
我怎么能这样做?
P.S。 :我正在使用带有带注释类的jpa的HibernateEntityManger。
UPADATE 这是我的代码,首先 我有4张桌子: 用户(ID,名字,姓氏,电子邮件....) 角色(ID,姓名,评论...) users_roles(USER_ID,ROLE_ID) 邮件(ID,USER_ID,主题,消息,to_id ...)
用户可以拥有多种角色.... 用户实体
@Entity
@Table(name = "USERS")
public class User implements GenericDomain{
public static final String _ID = "id";
private Long id;
private String firstName;
private String lastName;
private String email;
private Set<Role> roles = new HashSet<Role>(0);
/* Constructors */
public User() {
}
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name = "ID", unique = true, nullable = false)
public Long getId() { return this.id; }
public void setId(Long id) { this.id = id; }
@Column(name="FIRST_NAME", nullable = false, length = 64)
@NotEmpty
@Length(min = 4, max = 45)
public String getFirstName() { return this.firstName; }
public void setFirstName(String firstname) { this.firstName = firstname; }
@Column(name="LAST_NAME", nullable = false, length = 64)
@NotEmpty
@Length(min = 4, max = 45)
public String getLastName() { return this.lastName; }
public void setLastName(String lastname) { this.lastName = lastname; }
@Column(name="EMAIL", unique = false, length = 64)
@Email
@NotEmpty
@Length(min = 4, max = 45)
public String getEmail() { return this.email; }
public void setEmail(String email) { this.email = email; }
@ManyToMany(fetch=FetchType.EAGER)
@JoinTable(name = "USERS_ROLES"
, joinColumns = { @JoinColumn(name = "user_id") }
, inverseJoinColumns = { @JoinColumn(name = "role_id") }
)
public Set<Role> getRoles() {
return this.roles;
}
public void setRoles(Set<Role> roles) {
this.roles = roles;
}
/*@Override toString/equals/hascode */
}
角色实体
@Entity
@Table(name = "ROLES")
public class Role implements GenericDomain {
private Long id;
private String name;
private String comment;
private Set<User> users = new HashSet<User>(0);
public Role() {
}
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name = "ID", unique = true, nullable = false)
public Long getId() { return id; }
public void setId(Long id) { this.id = id; }
@Column(name="NAME", nullable = false, length = 64)
@NotEmpty
@Length(min = 1, max = 32)
public String getName() { return name; }
public void setName(String name) { this.name = name; }
@Column(name="COMMENT", nullable = true, length = 256)
@Length(min = 0, max = 255)
public String getComment() { return this.comment; }
public void setComment(String comment) { this.comment = comment;}
@ManyToMany(cascade=CascadeType.REFRESH,fetch=FetchType.EAGER)
@JoinTable(
name = "USERS_ROLES"
, joinColumns = { @JoinColumn(name = "role_id") }
, inverseJoinColumns = { @JoinColumn(name = "user_id") }
)
public Set<User> getUsers() {
return this.users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
/*@Override toString/equals/hascode */
}
邮件
@Entity @Table(name =“mails”) 公共类Mail实现GenericDomain {
private Long id;
private String mailSubject;
private String mailContent;
private Long receiverId;
private User user = null;
public Mail(){
}
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "ID", nullable = false)
public Long getId(){ return this.id; }
public void setId(Long id){ this.id = id;}
@Column(name = "MAILSUBJECT", nullable = false, length = 63)
@Length(max = 63)
public String getMailSubject(){ return this.mailSubject; }
public void setMailSubject(String mailSubject){ this.mailSubject = mailSubject; }
@Column(name = "MAILCONTENT", nullable = true, length = 255)
@Length(max = 255)
public String getMailContent(){ return this.mailContent; }
public void setMailContent(String mailContent){ this.mailContent = mailContent; }
@Column(name = "RECEIVERID")
public Long getReceiverId(){ return this.receiverId; }
public void setReceiverId(Long receiverId){ this.receiverId = receiverId; }
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name = "USER_ID")
@NotNull
public User getUser(){ return this.user; }
public void setUser(User user){ this.user = user; }
}
用户控制器
@Controller
@RequestMapping("/admin/user")
@SessionAttributes("user")
public class UserController {
private UserService userService;
private RoleService roleService;
@Autowired
public UserController(UserService userService, RoleService roleService) {
this.userService = userService;
this.roleService = roleService;
}
@RequestMapping(value = "edit", method = RequestMethod.GET)
public String editUser(@RequestParam(value="id", required = true) Long id, ModelMap model) {
model.addAttribute("allRoles", roleService.getAll());
model.addAttribute("user", userService.getOne(id));
return "/admin/user/edit";
} }
邮件控制器
@Controller
@SessionAttributes("mail")
@RequestMapping("/portal/mail")
public class MailController{
@Autowired
private MailService mailService;
@RequestMapping(value = "ajaxLoad", method = RequestMethod.GET)
public @ResponseBody List<Mail> list(@RequestParam(value = "type", required = true) String type){
return mailService.getUserMails((Long) WebHelper.getPrincipal().getUser().getId(),type);
}
}
我的web.xml
<filter>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
我的edit.jsp for user
<select >
<c:forEach items="${allRoles}" var="role">
<option value="${role.id}" <c:if test="${fn:contains(roleSelected, role)}">selected="selected"</c:if> >${role.name}</option>
</c:forEach>
</select>
尽管如此,我使用edit.jsp for lazy = false正常工作。 使用FetchType.EAGER我无法获取任何邮件,进入循环stackovrflow,没有FetchType.EAGER我得到了这个懒惰的异常。
答案 0 :(得分:2)
OpenEntityManagerInViewFilter
和OpenEntityManagerInViewInterceptor
有效。你做错了什么。
除此之外,您可以使用Hibernate.initialize(..)
初始化您的收藏。但手动执行此操作并不是首选。详细说明过滤器/拦截器不起作用的原因。
更新:不是将过滤器映射到模式,而是将其映射到调度程序servlet。因此,而不是指定<url-pattern>
specfiy <servlet-name>
。
答案 1 :(得分:2)
删除所有渴望并添加此解决我的问题
<mvc:interceptors>
<bean class="org.springframework.orm.jpa.support.OpenEntityManagerInViewInterceptor">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
</mvc:interceptors>
过滤器无法正常工作
答案 2 :(得分:-2)
首先,检查您是否真的需要Collection
而不是Set
。如果集合中的对象是唯一的,则将变量声明为Set
,这可以解决90%的LazyInitializationException
问题。