我仍然得到异常lazyinitializationexception。
是的，我知道这意味着，在我或其他人尝试访问集合时，会话已关闭。
否，OpenEntityManagerInViewFilter不起作用。
是的，@ ManyToOne(fetch = FetchType.EAGER)帮助了我，但我不想使用它，因为它会一直无声地传播。
我还能怎么做？
附言:我在带注释类的jpa中使用HibernateEntityManger。
更新
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，名称，评论...)
users_roles(user_id，role_id)
邮件(id，user_id，主题，消息，to_id ...)
用户可以具有多个角色...。
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
@实体
@Table(name =“邮件”)
公共类邮件实现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>
我的用户edit.jsp
<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>
有了所有这些，我为用户的edit.jsp与lazy = false一起正常工作。
使用FetchType.EAGER无法获取我的任何邮件，进入了一个循环stackovrflow，如果没有FetchType.EAGER我就得到了那个懒惰的异常。
最佳答案
消除所有的渴望并添加这个解决我的问题
<mvc:interceptors>
<bean class="org.springframework.orm.jpa.support.OpenEntityManagerInViewInterceptor">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
</mvc:interceptors>
过滤器没有工作
关于java - 如何不使用fetch = FetchType.EAGER解决lazyinitializationexception？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/4263464/