在eclipse上配置Hibernate、stripersist答案

【问题标题】：configuring Hibernate, stripersist on eclipse在eclipse上配置Hibernate、stripersist
【发布时间】：2011-12-21 00:35:53
【问题描述】：

我曾尝试将 stripersist 与 mysql 一起使用，但没有成功。

我已将 stripes book 的示例代码 email23 复制到 eclipse 并添加 res 文件夹作为源文件夹。

当我尝试运行应用程序时，我收到以下错误

SEVERE: Servlet.service() for servlet DispatcherServlet threw exception
java.lang.NullPointerException
    at stripesbook.dao.impl.stripersist.BaseDaoImpl.read(BaseDaoImpl.java:46)
    at stripesbook.ext.MyActionBeanContext.getUser(MyActionBeanContext.java:60)
    at stripesbook.action.BaseActionBean.getUser(BaseActionBean.java:93)
    at stripesbook.action.ContactListActionBean.getContacts(ContactListActionBean.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at javax.el.BeanELResolver.getValue(BeanELResolver.java:83)
    at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
    at org.apache.el.parser.AstValue.getValue(AstValue.java:123)
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
    at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:938)
    at org.apache.jsp.WEB_002dINF.jsp.contact_005flist_jsp._jspService(contact_005flist_jsp.java:177)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    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:646)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
    at net.sourceforge.stripes.action.ForwardResolution.execute(ForwardResolution.java:110)
    at net.sourceforge.stripes.controller.DispatcherHelper$7.intercept(DispatcherHelper.java:483)
    at net.sourceforge.stripes.controller.ExecutionContext.proceed(ExecutionContext.java:158)
    at net.sourceforge.stripes.controller.HttpCacheInterceptor.intercept(HttpCacheInterceptor.java:99)
    at net.sourceforge.stripes.controller.ExecutionContext.proceed(ExecutionContext.java:155)
    at net.sourceforge.stripes.controller.BeforeAfterMethodInterceptor.intercept(BeforeAfterMethodInterceptor.java:113)
    at net.sourceforge.stripes.controller.ExecutionContext.proceed(ExecutionContext.java:155)
    at net.sourceforge.stripes.controller.ExecutionContext.wrap(ExecutionContext.java:74)
    at net.sourceforge.stripes.controller.DispatcherHelper.executeResolution(DispatcherHelper.java:477)
    at net.sourceforge.stripes.controller.DispatcherServlet.executeResolution(DispatcherServlet.java:293)
    at net.sourceforge.stripes.controller.DispatcherServlet.doPost(DispatcherServlet.java:177)
    at net.sourceforge.stripes.controller.DispatcherServlet.doGet(DispatcherServlet.java:67)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at net.sourceforge.stripes.controller.StripesFilter.doFilter(StripesFilter.java:246)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:680)

我已经检查了这个帖子 Help configuring Hibernate,Jpa, Stripesist on Stripes ，但还是有问题

感谢任何帮助。

【问题讨论】：

我会假设 Stripersist 在这种情况下为空，这意味着它没有正确启动。你在启动时得到任何关于 Stripersist 的堆栈跟踪吗？有没有关于 stripersist 成功启动的日志？

标签： hibernate stripes

【解决方案1】：

您的代码在返回 null 的 getEntityManager() 上失败：

45: public T read(ID id) {
46:    return Stripersist.getEntityManager().find(entityClass, id);
47: }

这意味着您没有为您的 Web 应用程序正确配置 Hibernate/JPA。

您可能会发现此文档很有帮助（尽管您可以遵循任何 Hibernate/JPA 配置指南，因为配置不是 Stripersist 或 Stripes 特定的）： http://www.stripesframework.org/display/stripes/Hibernate+configuration

【讨论】：