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我試圖在級聯中映射兩個多對多關聯。我有三個類：用戶，用戶組和權限。第一個與第二個有多對多的關聯，而第二個與第三個有多對多的關聯。休眠 - 多對多關聯 - 不能同時獲取多個行包
我使用休眠4.2.0
@Entity
@Table(name = "user")
public class User implements Serializable {
@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, targetEntity = org.weedea.bidupsys.user.logic.model.UserGroup.class)
@JoinTable(name = "UserGroupUser", joinColumns = { @JoinColumn(name = "userId") }, inverseJoinColumns = { @JoinColumn(name = "userGroupId") })
private List<UserGroup> userGroupList = null;
}
@Entity
@Table(name = "userGroup")
public class UserGroup implements Serializable {
@ManyToMany(fetch = FetchType.EAGER, targetEntity = org.weedea.bidupsys.user.logic.model.Permission.class, cascade = { CascadeType.ALL })
@JoinTable(name = "UserGroupPermission", joinColumns = { @JoinColumn(name = "userGroupId") }, inverseJoinColumns = { @JoinColumn(name = "permissionId") })
private List<Permission> permissionList = null;
}
有了這個配置，我得到一個錯誤，因爲我嘗試加載同時在兩個渴望集合：
javax.servlet.ServletException: cannot simultaneously fetch multiple bags
javax.faces.webapp.FacesServlet.service(FacesServlet.java:229)
如果我把取= FetchType .LAZY第二集合，我得到另一個錯誤：
failed to lazily initialize a collection of role: org.weedea.bidupsys.user.logic.model.UserGroup.permissionList, could not initialize proxy - no Session
我怎麼能映射這兩個manyŧ o很多協會？感謝幫助！