未能延迟初始化集合…，无法初始化代理-无会话

Question

我有一个应用程序，我正在扩展它以提供REST API。在主站点中一切正常，但当我尝试访问REST API时，我在异常日志中得到以下内容：

"Error","ajp-bio-8014-exec-3","12/02/14","12:54:06","table","failed to lazily initialize a collection of role: field, could not initialize proxy - no Session The specific sequence of files included or processed is: service.cfc'' "
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: field, could not initialize proxy - no Session
    at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:566)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:186)
    at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:137)
    at org.hibernate.collection.internal.PersistentBag.size(PersistentBag.java:242)
    at coldfusion.runtime.xml.ListIndexAccessor.getSize(ListIndexAccessor.java:44)
    at coldfusion.runtime.xml.ArrayHandler.serialize(ArrayHandler.java:69)
    at coldfusion.runtime.xml.CFComponentHandler.serialize(CFComponentHandler.java:106)
    at coldfusion.runtime.XMLizerUtils.serializeXML(XMLizerUtils.java:83)
    at coldfusion.rest.provider.CFObjectProvider.writeTo(CFObjectProvider.java:378)
    at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:306)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1479)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1391)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1381)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:538)
    at coldfusion.rest.servlet.CFRestServletContainer.service(CFRestServletContainer.java:141)
    at coldfusion.rest.servlet.CFRestServletContainer.service(CFRestServletContainer.java:86)
    at coldfusion.rest.servlet.CFRestServlet.serviceUsingAlreadyInitializedContainers(CFRestServlet.java:556)
    at coldfusion.rest.servlet.CFRestServlet.invoke(CFRestServlet.java:434)
    at coldfusion.rest.servlet.RestFilter.invoke(RestFilter.java:58)
    at coldfusion.filter.ExceptionFilter.invoke(ExceptionFilter.java:94)
    at coldfusion.filter.ClientScopePersistenceFilter.invoke(ClientScopePersistenceFilter.java:28)
    at coldfusion.filter.GlobalsFilter.invoke(GlobalsFilter.java:38)
    at coldfusion.filter.DatasourceFilter.invoke(DatasourceFilter.java:22)
    at coldfusion.rest.servlet.CFRestServlet.invoke(CFRestServlet.java:409)
    at coldfusion.rest.servlet.CFRestServlet.service(CFRestServlet.java:400)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    at coldfusion.bootstrap.BootstrapServlet.service(BootstrapServlet.java:89)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at coldfusion.monitor.event.MonitoringServletFilter.doFilter(MonitoringServletFilter.java:42)
    at coldfusion.bootstrap.BootstrapFilter.doFilter(BootstrapFilter.java:46)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:422)
    at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:198)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

禁用延迟加载将解决此问题，但会导致不可接受的性能（加载时间从 200 毫秒到 22 秒）。我不知道如何处理这个问题。

我刚开始在ColdFusion中Rest，在我看来，CFC正在以一种不寻常的方式被处理。它们似乎没有被初始化(init方法似乎没有运行),现在看来ORM也没有得到同样的处理。我错过了什么吗？

以下是产生此错误的代码摘录：

component rest="true" restpath="item" 
{
    import model.beans.*;

    remote item function getitem( numeric id restargsource="Path" ) restpath="{id}" httpmethod="GET"
    {
        var item = entityLoad("item",{ id = id },true);

        return item;
    }

}

和豆子：

component persistent="true" table="item" output="false" extends="timestampedBean" batchsize="10" cacheuse="read-only"
{
    /* properties */

    property name="id" column="id" type="numeric" ormtype="int" fieldtype="id" generator="identity"; 
    property name="title" column="title" type="string" ormtype="string"; 
    property name="description" column="description" type="string" ormtype="string"; 
    property name="status" column="status" type="numeric" ormtype="byte" default="0" ; 
    property name="user" fieldtype="many-to-one" cfc="user" fkcolumn="userid" inversejoincolum="userid" lazy="true" cacheuse="read-only";
    property name="field" type="array" fieldtype="many-to-many" cfc="field" fkcolumn="id" linktable="items_fields" inversejoincolumn="fieldid" lazy="extra" batchsize="10" cacheuse="read-only";
}

我还注意到，在标准输出日志中，Hibernate正在记录查询，但随后记录了“无会话”错误：

Hibernate: 
    select
        item0_.id as id0_0_,
        item0_.dtcreated as dtcreated0_0_,
        item0_.dtmodified as dtmodified0_0_,
        item0_.title as title0_0_,
        item0_.description as descript6_0_0_,
        item0_.status as status0_0_,
        item0_.userid as userid0_0_ 
    from
        item item0_ 
    where
        item0_.id=?
Dec 2, 2014 15:23:00 PM Error [ajp-bio-8014-exec-3] - failed to lazily initialize a collection of role: field, could not initialize proxy - no Session The specific sequence of files included or processed is: service.cfc''

我可能还应该补充一点，这个“item”表是多对多关系的一部分，所以“collection of role: field”引用的是外部表。

Answer 1

将列表设置为空

示例:

迭代对象并将每个实体列表设置为空

entity.setList（null）；

Answer 2

org.hibernate.LazyInitializationException是一个流行的Hibernate问题。根本原因是您没有打开Hibernate会话，因为没有可用的事务。有几种方法可以克服这个问题。请阅读以下链接：

http://www.javacodegeeks.com/2012/07/four-solutions-to-lazyinitializationexc_05.html http://javarevisited.blogspot.ru/2014/04/orghibernatelazyinitializationException-Could-not-initialize-proxy-no-session-hibernate-java.html

或者您可以使用

<代码>

4.1.6之后是hibernate版本。有关使用Hibernate.enable_Lazy_load_no_trans解决Hibernate懒惰初始化问题的更多信息，请参阅