Jsf 根据数据库中的用户输入创建Datatable

我有两个Primeface数据表和自己的panelGroup。 一个用于从用户输入。 第二个用于显示数据库中的数据。 它取决于selectOneMenu选项

XHTML文件：

<h:body>
<h:form id="form">
    <!-- Select One Menu For Invoice Data -->
    <br />
    <h3 align="center">Tax Invoice</h3>
    <p:selectOneMenu id="selectOne" value="#{invoiceBean.selectOneOption}"
        required="true">
        <f:selectItem itemValue="Add New Invoice" itemLabel="Add New Invoice" />
        <f:selectItem itemValue="Old Invoice" itemLabel="Old Invoice" />
        <f:ajax render="groups" />
    </p:selectOneMenu>

    <h:panelGroup id="groups">
        <h:panelGroup id="inputs"
            rendered="#{invoiceBean.selectOneOption == 'Add New Invoice'}">
            <table border="1" id="invoiceData">
                <tr>
                    <td> 1 </td>
                    <td> 2 </td>
                </tr>


            </table>
        </h:panelGroup>
        <h:panelGroup id="outputs"
            rendered="#{invoiceBean.selectOneOption == 'Old Invoice'}">
            <p:panelGrid columns="3">
                <p:outputLabel value="Enter Invoice Number :" />
                <p:inputText id="inputInvoiceNumber"
                    value="#{invoiceBean.invoiceNumber}" />
                <p:commandButton value="Search" type="submit">
                    <f:ajax execute="inputInvoiceNumber" render="outputInvoiceNumber" />
                </p:commandButton>
            </p:panelGrid>
            <br />
            <p:dataTable id="outputInvoiceNumber"
                value="#{invoiceBean.invoiceByContrId}" var="invoice">
                <p:column headerText="Invoice Id ">
                    <p:outputLabel value="#{invoice.id}" />
                </p:column>
            </p:dataTable>
        </h:panelGroup>
    </h:panelGroup>
</h:form>
</h:body>

这是在Tomcat服务器中运行代码时出现的错误。

---

它包含空指针异常错误和其他错误。

这里有什么问题？您已经使用UI绑定了invoice bean的invoiceNumber。您可以在bean中获得它的值。您是否收到任何错误？是否可以在此处打印堆栈跟踪以及出现异常的点？我认为您的getInvoiceByContrId方法第一次返回null，因为发票号尚未更新。如果从DAO得到null，请尝试返回空数组列表。谢谢老板，但是出现了另一个问题，这已经在我的错误代码中了。javax.el.ELException:/index.xhtml@132,60 value={invoiceean.invoiceycontrid}：在com.billing.managebeans.invoiceean类型上读取“invoiceycontrid”时出错您在代码中做了哪些更改？你能更新你的帖子吗。

public List<Invoice> getInvoiceByContrId() {
    invoiceDao = new InvoiceDao();
    invoices = new ArrayList<Invoice>();

    try {
        invoices = invoiceDao.getInvoiceId(invoiceNumber);
        if (null == invoices) {
            invoices = Collections.emptyList();
        }
        return invoices;
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        invoices = Collections.emptyList();
        return invoices;
    }
}

public List<Invoice> getInvoiceId(String invoiceNumber) {

    List<Invoice> invoiceList = new ArrayList<Invoice>();
    try {
        startReadOperation();
        System.out.println("InvoiceDao.getIpsData()");
        String sql = "SELECT * FROM invoice where invoice_number = :invoiceNumber";
        SQLQuery query = session.createSQLQuery(sql);
        query.setParameter("invoiceNumber", invoiceNumber);
        query.addEntity(Invoice.class);
        invoiceList = query.list();

    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
    finally {
        endOperation();
    }
    return invoiceList;
}

javax.el.ELException: /index.xhtml @132,60 value="#{invoiceBean.invoiceByContrId}": Error reading 'invoiceByContrId' on type com.billing.managebeans.InvoiceBean
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:114)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIData.getValue(UIData.java:731)
at org.primefaces.component.datatable.DataTable.getValue(DataTable.java:1002)
at org.primefaces.component.api.UIData.getDataModel(UIData.java:629)
at javax.faces.component.UIData.getRowCount(UIData.java:356)
at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:762)
at org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:744)
at org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:258)
at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:220)
at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:84)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:312)
at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:105)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:304)
at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:105)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:399)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
at com.billing.dao.AbstractDao.commit(AbstractDao.java:46)
at com.billing.dao.AbstractDao.endOperation(AbstractDao.java:60)
at com.billing.dao.InvoiceDao.getInvoiceId(InvoiceDao.java:108)
at com.billing.managebeans.InvoiceBean.getInvoiceByContrId(InvoiceBean.java:213)
at sun.reflect.GeneratedMethodAccessor136.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at javax.el.BeanELResolver.getValue(BeanELResolver.java:87)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstValue.getValue(AstValue.java:183)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
... 49 more