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大家好我都顯示在JSP學生數據，在JSP中所選擇的數據我有數據庫來存儲我寫了下面的代碼在這裏如何避免重複的數據插入到數據庫如何避免重複插入休眠
public void addToPreviousSchoolInfo(String[] studentReferencIDS,
String[] studentName, String[] studentclass,
double[] studentPercentage, String[] studentObtainedClass) {
PreviousClassInformation previousClassInformationDTO=null;
Session session = null;
Transaction tx = null;
try {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
session = sessionFactory.openSession();
tx = session.beginTransaction();
for (int i = 0; i < studentReferencIDS.length; i++) {
previousClassInformationDTO=new PreviousClassInformation();
previousClassInformationDTO.setStudentReferenceID(studentReferencIDS[i]);
previousClassInformationDTO.setStudentName(studentName[i]);
previousClassInformationDTO.setClassName(studentclass[i]);
previousClassInformationDTO.setPercentage(studentPercentage[i]);
previousClassInformationDTO.setObtainedClass(studentObtainedClass[i]);
session.saveOrUpdate(previousClassInformationDTO);
}
tx.commit();
} catch (HibernateException he) {
he.printStackTrace();
tx.rollback();
}
}
我試圖像這樣
public void addToPreviousSchoolInfo(String[] studentReferencIDS,
String[] studentName, String[] studentclass,
double[] studentPercentage, String[] studentObtainedClass) {
PreviousClassInformation previousClassInformationDTO=null;
Session session = null;
Transaction tx = null;
try {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
session = sessionFactory.openSession();
tx = session.beginTransaction();
tx.begin();
for (int i = 0; i < studentReferencIDS.length; i++) {
Criteria criteria = session.createCriteria(PreviousClassInformation.class);
criteria.add(Restrictions.eq("studentReferenceID", studentReferencIDS[i]));
criteria.add(Restrictions.eq("className", studentclass[i]));
criteria.setProjection(Projections.rowCount());
long count = (Long) criteria.uniqueResult();
session.getTransaction().commit();
if(count != 0){
System.out.println("present");
}
else{
previousClassInformationDTO=new PreviousClassInformation();
previousClassInformationDTO.setStudentReferenceID(studentReferencIDS[i]);
previousClassInformationDTO.setStudentName(studentName[i]);
previousClassInformationDTO.setClassName(studentclass[i]);
previousClassInformationDTO.setPercentage(studentPercentage[i]);
previousClassInformationDTO.setObtainedClass(studentObtainedClass[i]);
session.saveOrUpdate(previousClassInformationDTO);
}
}
tx.commit();
} catch (HibernateException he) {
he.printStackTrace();
tx.rollback();
}
}
錯誤
Hibernate: select count(*) as y0_ from previousclassinfo this_ where this_.studentReferenceID=? and this_.className=?
Hibernate: select max(ID) from previousclassinfo
Hibernate: select count(*) as y0_ from previousclassinfo this_ where this_.studentReferenceID=? and this_.className=?
org.hibernate.TransactionException: Transaction not successfully started
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:127)
at com.infonex.sms.daoImpl.classpromotion.ClassProtmotionDAOImpl.addToPreviousSchoolInfo(ClassProtmotionDAOImpl.java:97)
at com.infonex.sms.controller.classpromotion.ClassPromotion.promoteStudentsToNextClass(ClassPromotion.java:93)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at com.infonex.sms.filters.Clickjacking.doFilter(Clickjacking.java:55)
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:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)