我在任何Crud操作期间通过hibernate中的findbyId（）方法遇到问题（并非总是如此）;它正意外地出现（在任何不确定的时间，10％的机会提出问题）。 但在重新加载页面（再次从浏览器发送请求）后，它会获得所需的数据;没问题。
I have checked with all methods of hibernate(4.1.7) for findById such as get(), load(), byId.load(), criteria, but invain.
given my testing code snippet:
public SurveyDefination findById(final long sdId) throws HibernateException {
/*
* Session session1 = HibernateUtil.getSessionFactory().openSession();
* session1.beginTransaction();
*/
Criteria criteria = session.createCriteria(SurveyDefination.class).add(
Restrictions.idEq(sdId));
SurveyDefination surveyDefination = (SurveyDefination) criteria
.uniqueResult();
if (surveyDefination == null) {
int count = 0;
System.out
.println("Before------surveyDefination--------Output --------- :: "
+ count++ + ": " + surveyDefination);
// session.evict(surveyDefination);
if (surveyDefination == null && count == 1) {
surveyDefination = (SurveyDefination) session.get(
SurveyDefination.class, sdId);
System.out
.println("Before------surveyDefination--------Output -----get()---- :: "
+ count++ + ": " + surveyDefination);
}
if (surveyDefination == null)
try {
surveyDefination = (SurveyDefination) session.load(
SurveyDefination.class, sdId);
System.out
.println("Before------surveyDefination--------Output -----load()---- :: "
+ count++ + ": " + surveyDefination);
} catch (HibernateException e) {
logger.error(e.getMessage() + " ObjectNotFoundException");
e.printStackTrace();
}
if (surveyDefination == null) {
surveyDefination = (SurveyDefination) session.byId(
SurveyDefination.class).load(sdId);
logger.info("Before------surveyDefination--------Output -----byId().load()---- :: "
+ count++ + ": " + surveyDefination);
}
if (surveyDefination == null) {
criteria = session.createCriteria(SurveyDefination.class).add(
Restrictions.idEq(sdId));
surveyDefination = (SurveyDefination) criteria.uniqueResult();
System.out
.println("Before------surveyDefination--------Output -----createCriteria()---- :: "
+ count++ + ": " + surveyDefination);
}
}
System.out
.println("After -----surveyDefination---------Output --------- :: "
+ surveyDefination);
return surveyDefination;
}
But after all checking if it gets null once, it will never get the result;
but same request by resending immediately, desired output comes out.
Following is the error from my console, plz give a reason for such issue.
11:06:50,987 INFO [stdout] (http-localhost-127.0.0.1-8080-4) connection is idle true connection release count 2
11:06:51,012 INFO [stdout] (http-localhost-127.0.0.1-8080-4) Before------surveyDefination--------Output --------- :: 0: null
11:06:51,018 INFO [stdout] (http-localhost-127.0.0.1-8080-4) Before------surveyDefination--------Output -----get()---- :: 1: null
11:06:51,027 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.ttn.survey.model.SurveyDefination#322]
11:06:51,027 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.internal.SessionFactoryImpl$1$1.handleEntityNotFound(SessionFactoryImpl.java:242)
11:06:51,028 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.checkTargetState(AbstractLazyInitializer.java:248)
11:06:51,028 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:176)
11:06:51,029 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:272)
11:06:51,029 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185)
11:06:51,030 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.model.SurveyDefination_$$_javassist_95.toString(SurveyDefination_$$_javassist_95.java)
11:06:51,030 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.String.valueOf(String.java:2847)
11:06:51,030 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.StringBuilder.append(StringBuilder.java:128)
11:06:51,031 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.controller.implementations.dao.SurveyDefinationDAOImpl.findById(SurveyDefinationDAOImpl.java:132)
11:06:51,031 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.controller.implementations.client.ClientSurveyActionImpl.findSurveyInfoById(ClientSurveyActionImpl.java:213)
11:06:51,032 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.view.client.SurveyControllerServlet.doGet(SurveyControllerServlet.java:199)
11:06:51,032 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
11:06:51,032 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
11:06:51,033 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329)
11:06:51,033 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
11:06:51,034 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:840)
11:06:51,034 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:622)
11:06:51,034 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:560)
11:06:51,035 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:488)
11:06:51,035 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:213)
11:06:51,036 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:171)
11:06:51,036 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
11:06:51,037 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
11:06:51,037 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:394)
11:06:51,037 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280)
11:06:51,038 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
11:06:51,038 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275)
11:06:51,039 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
11:06:51,039 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153)
11:06:51,039 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155)
11:06:51,040 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
11:06:51,041 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
11:06:51,041 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368)
11:06:51,042 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877)
11:06:51,042 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671)
11:06:51,043 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930)
11:06:51,043 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.Thread.run(Thread.java:745)
11:06:51,043 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.ttn.survey.model.SurveyDefination#322]
11:06:51,044 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.internal.SessionFactoryImpl$1$1.handleEntityNotFound(SessionFactoryImpl.java:242)
11:06:51,044 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.checkTargetState(AbstractLazyInitializer.java:248)
11:06:51,045 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:180)
11:06:51,045 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:272)
11:06:51,046 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185)
11:06:51,046 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.model.SurveyDefination_$$_javassist_95.toString(SurveyDefination_$$_javassist_95.java)
11:06:51,047 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.String.valueOf(String.java:2847)
11:06:51,047 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.StringBuilder.append(StringBuilder.java:128)
11:06:51,047 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.controller.implementations.dao.SurveyDefinationDAOImpl.findById(SurveyDefinationDAOImpl.java:157)
11:06:51,048 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.controller.implementations.client.ClientSurveyActionImpl.findSurveyInfoById(ClientSurveyActionImpl.java:213)
11:06:51,048 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at com.ttn.survey.view.client.SurveyControllerServlet.doGet(SurveyControllerServlet.java:199)
11:06:51,049 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
11:06:51,049 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
11:06:51,049 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329)
11:06:51,050 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
11:06:51,050 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:840)
11:06:51,051 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:622)
11:06:51,051 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:560)
11:06:51,051 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:488)
11:06:51,052 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:213)
11:06:51,052 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:171)
11:06:51,053 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
11:06:51,053 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
11:06:51,054 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:394)
11:06:51,054 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280)
11:06:51,054 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
11:06:51,055 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275)
11:06:51,055 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
11:06:51,056 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153)
11:06:51,057 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155)
11:06:51,058 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
11:06:51,058 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
11:06:51,059 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368)
11:06:51,059 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877)
11:06:51,059 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671)
11:06:51,060 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930)
11:06:51,060 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) at java.lang.Thread.run(Thread.java:745)
答案 0 :(得分：0)
这个问题
surveyDefination = (SurveyDefination) session.load(
SurveyDefination.class, sdId);
您无法使用load（）方法加载不存在的持久性。所以你在SurveyDefination的toString（）中得到一个例外（因为我认为，因为你不提供行号）
System.out.println("Before------surveyDefination--------Output
-----load()---- :: " + count++ + ": " + surveyDefination);
P.S。如果你想看一些使用Hibernate的技巧，你可以看到它here