如何在JSP dataTable中显示列表条目？

时间：2019-01-18 23:57:55

标签： java hibernate jsp

我无法让jsp tableData遍历列表对象并显示每条记录。

我正在为一个学校项目工作，被困住了。我应该使用Hibernate与SQL数据库（Oracle 11g XE）进行通信，并创建简单的用户界面来管理数据库中的条目。

现在，我能够查询数据库并将所有记录从指定表中获取到ArrayList并通过Java ManagedBean传递。

jsp file:

<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<jsp:useBean id="datamodel" class="Magazyn.DaneCzesc" scope="session" />
<jsp:setProperty name="datamodel" property="*" />
<!DOCTYPE html>
<html xmlns:h="http://xmlns.jcp.org/jsf/html" xmlns:f="http://xmlns.jcp.org/jsf/core">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Wyswietl czesc</title>
    </head>
    <body>
        <h:dataTable value="#{datamodel.tableValues}" var="czesc"> 

            <h:column id="col1" headerClass="color:purple">
                <f:facet name="header">ID</f:facet>
                <h:outputText value="#{czesc.id_czesc}"/>
            </h:column>

            <h:column id="col2" headerClass="color:purple">
                <f:facet name="header">NAZWA</f:facet>
                <h:outputText value="#{czesc.nazwa_czesci}"/>
            </h:column>

            <h:column id="col3" headerClass="color:purple">
                <f:facet name="header">OPIS</f:facet>
                <h:outputText value="#{czesc.opis}"/>
            </h:column>

            <h:column id="col4" headerClass="color:purple">
                <f:facet name="header">INFORMACJE DODATKOWE</f:facet>
                <h:outputText value="#{czesc.inf_dodatkowe}"/>
            </h:column>

            <h:column id="col5" headerClass="color:purple">
                <f:facet name="header">CZAS OCZEKIWANIA</f:facet>
                <h:outputText value="#{czesc.czas_oczekiwania_zamowienie}"/>
            </h:column>

            <h:column id="col6" headerClass="color:purple">
                <f:facet name="header">ILOŚĆ</f:facet>
                <h:outputText value="#{czesc.ilosc}"/>
            </h:column>
        </h:dataTable>
</body>
</html>

Java class:

package Magazyn;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.model.ListDataModel;
import org.hibernate.Query;
import org.hibernate.Session;

@ManagedBean(name="datamodel")
@SessionScoped

public class DaneCzesc extends ListDataModel implements ActionListener{

    private Czesc cz;
    private MagazynHibernateUtil helper; 
    private Session session;
    private ArrayList <String> lista = new ArrayList<>();
    private ArrayList<Czesc> tableValues;
    private Integer id_czesc;

    public ArrayList<Czesc> getTableValues(){
        try{
            session = MagazynHibernateUtil.getSessionFactory().openSession();
            //org.hibernate.Transaction tx = session.beginTransaction();
            //tx.begin();
            tableValues = new ArrayList<>();
            Query q = session.createQuery("from Czesc");
            tableValues = (ArrayList<Czesc>) q.list();
            //tx.commit();
            session.close();
        }
        catch (Exception ex){}
        return tableValues;
    } 

    public void addCzesc(String a, String b, String c, String d, int e){
        cz = new Czesc(a,b,c,d,e);
        session = MagazynHibernateUtil.getSessionFactory().openSession();
        session.beginTransaction();
        session.save(cz);
        session.getTransaction().commit();
        session.close();
    } 

    public String delete(){
        return null;
    }    

    @Override
    public void actionPerformed(ActionEvent e) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
}

Apache server log:

19-Jan-2019 00:38:26.178 SEVERE [http-nio-8084-exec-386] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [jsp] in context with path [/MagazynSBD] threw exception [An exception occurred processing JSP page /WyswietlCzesc.jsp at line 20

17:         <title>Wyswietl czesc</title>
18:     </head>
19:     <body>
20:         <h:dataTable value="#{datamodel.tableValues}" var="czesc"> 
21: 
22:             <h:column id="col1" headerClass="color:purple">
23:                 <f:facet name="header">ID</f:facet>


Stacktrace:] with root cause
 java.lang.NullPointerException
    at javax.faces.webapp.UIComponentClassicTagBase.setJspId(UIComponentClassicTagBase.java:1856)
    at org.apache.jsp.WyswietlCzesc_jsp._jspx_meth_h_005fdataTable_005f0(WyswietlCzesc_jsp.java:185)
    at org.apache.jsp.WyswietlCzesc_jsp._jspService(WyswietlCzesc_jsp.java:148)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

使用tableData是首选方法，但是我可以使用anu other来显示我的数据。

0 个答案:

没有答案
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