java - hibernate 和 spring 中没有 session 代理

Question

我正在创建一个职位门户管理员。我正在使用 Spring + hibernate 。我已经为添加工作创建了页面，它工作正常，但是当我使用同一页面编辑工作时，出现异常:

org.hibernate.LazyInitializationException: could not initialize proxy - no Session
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:132)
    at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:174)
    at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:190)
    at com.jobs.admin.data.Company_$$_javassist_5.toString(Company_$$_javassist_5.java)
    at org.springframework.util.ObjectUtils.nullSafeToString(ObjectUtils.java:560)
    at org.springframework.util.ObjectUtils.getDisplayString(ObjectUtils.java:506)
    at org.springframework.web.servlet.tags.form.SelectedValueComparator.exhaustiveCompare(SelectedValueComparator.java:178)
    at org.springframework.web.servlet.tags.form.SelectedValueComparator.isSelected(SelectedValueComparator.java:103)
    at org.springframework.web.servlet.tags.form.OptionTag.isSelected(OptionTag.java:243)
    at org.springframework.web.servlet.tags.form.OptionTag.renderOption(OptionTag.java:211)
    at org.springframework.web.servlet.tags.form.OptionTag.renderFromBodyContent(OptionTag.java:161)
    at org.springframework.web.servlet.tags.form.AbstractHtmlElementBodyTag.doEndTag(AbstractHtmlElementBodyTag.java:66)
    at org.apache.jsp.WEB_002dINF.jsp.admin.addJob_jsp._jspService(addJob_jsp.java:735)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)
    at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
    at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
    at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1060)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:798)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:552)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run

(Thread.java:619)

我的 Controller 类有两种方法，一种用于添加作业，一种用于编辑该作业。为什么会这样，请给点建议。

Answer 1

为什么会这样:

看起来像在 JSP 中调用 Company 的 toString 方法。这会触发一个(公司)对象加载(它只加载了 layz)。因为您在 JSP 中没有 hibernate session ，所以您会收到此错误。

给点建议:

• 不好的建议:不要使用layzloading
• 其他不好的建议:访问该对象的 ，以便在事务内触发加载
• 真正的建议:使用 OpenSessionInViewFilter或 OpenEntityManagerInViewFilter