异常总结

一、org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.ptn.uim.bean.UimServFileRecord.uimServFileDatas,

no session or session was closed

错误原因：

原因是在hibernate映射关系中由于延迟加载，session在调用前已经被关闭，，所以加载set属性时无可用session

解决方案：

在 @ManyToOne端设置fetch=FetchType.LAZY,@OneToMany端设置fetch=FetchType.EAGER，如下配置

@ManyToOne(cascade={CascadeType.REFRESH, CascadeType.MERGE}, optional=true, fetch=FetchType.LAZY)
@JoinColumn(name="uim_serv_file_record_id")
private UimServFileRecord uimServFileRecord;

@OneToMany(cascade=CascadeType.ALL,fetch=FetchType.EAGER,mappedBy="uimServFileRecord")
private Set<UimServFileData> uimServFileDatas=new HashSet<UimServFileData>();