Question

遵循关于primefaces数据表的XHTML代码。

<h:panelGroup id="mode">
                    <p:panelGrid columns="2">
                        <p:panelGrid columns="2">
                            <p:outputLabel style="font-weight: bold;"
                                value="Mode Of Payments" />
                            <p:selectOneRadio value="#{invoiceBean.modeOfPayment}"
                                layout="pageDirection">
                                <f:ajax render="mode" />
                                <f:selectItem itemLabel="Cash" itemValue="Cash" />
                                <f:selectItem itemLabel="Cheque" itemValue="Cheque" />
                            </p:selectOneRadio>
                            <p:outputLabel value="Enter Bank Name :" />
                            <p:inputText value="#{invoiceBean.bankName}"
                                disabled="#{invoiceBean.modeOfPayment == 'Cash'}" />
                            <p:outputLabel value="Enter Cheque Number :" />
                            <p:inputText value="#{invoiceBean.chequeNumber}"
                                disabled="#{invoiceBean.modeOfPayment == 'Cash'}" />
                            <p:outputLabel value="Enter Amount :" />
                            <p:inputText value="#{invoiceBean.chequeAmount}" />
                        </p:panelGrid>
                        <p:panelGrid columns="1">
                            <p:dataTable id="transactionTable"
                                value="#{invoiceBean.transactions}" var="transaction">
                                <p:column headerText="Mode Of Payment">
                                    <p:outputLabel value="#{transaction.modeOfPayment}" />
                                </p:column>
                                <p:column headerText="Bank Name">
                                    <p:outputLabel value="#{transaction.bankName}" />
                                </p:column>
                                <p:column headerText="Amount">
                                    <p:outputLabel value="#{transaction.chequeAmount}" />
                                </p:column>
                                <p:column headerText="Balance">
                                    <p:outputLabel value="#{transaction.balance}" />
                                </p:column>
                                <p:summaryRow>
                                    <p:column colspan="3">
                                        <p:outputLabel value="Remaining Balance" />
                                    </p:column>
                                    <p:column>
                                        <p:outputLabel value="#{transaction.balance}" />
                                    </p:column>
                                </p:summaryRow>
                            </p:dataTable>
                        </p:panelGrid>
                    </p:panelGrid>
                </h:panelGroup>
                <p:commandButton value="Save New Invoice"
                    action="#{invoiceBean.addRow}"
                    update=":form:invoiceTable :form:transactionTable growl"
                    process="@form invoiceTable" onclick="PF('addInvoice').hide();">
                    <f:ajax render=":form:transactionTable" />
                    <f:ajax render=":form:invoiceTable" />
                </p:commandButton>

遵循transactionTable的托管bean代码：

@PostConstruct
public void init() {
    session = (HttpSession) FacesContext.getCurrentInstance().getExternalContext().getSession(true);
    transactionDao = new TransactionDao();
    invoiceDao = new InvoiceDao();
    invoices = invoiceDao.getInvoiceData(invoiceNumber);
    transactions = transactionDao.getTransactions(invoices.get(0).getId());
    invoiceProductsServicesDetails = invoiceDao
            .getInvoiceProductsServicesDetailDatas();
}

当我在HTML表格中添加新记录时，当点击“保存新发票”时，它将显示在transactionTable中。它的工作第一次正常但当我点击单选按钮并选择“检查”选项时，新数据不会显示，并且它会替换旧数据。

Answer 1

你不应该在getter / setter中执行业务逻辑。

正常的getter / setter对看起来像这样（就像普通的IDE会为你自动生成一样）：

public List<Transaction> getTransactions() {
    return transactions;
}

public void setTransactions(List<Transaction> transactions) {
    this.transactions = transactions;
}

除非你真的知道自己在做什么，否则不应该改变它们。在您的特定情况下，<p:dataTable>在每次迭代轮次中调用getter。你基本上是为每一行调用DAO。这没有意义。如果有大量记录，这会对性能产生巨大影响。

为了预加载视图数据，其中一种方法是@PostConstruct方法（对于这种视图，bean应该最好是@ViewScoped）：

@PostConstruct
public void init() {
    transactions = transactionDao.getTransactions(invoices.get(0).getId());
}

为了在编辑后保存/更新数据，只需使用动作（监听器）方法。

另见：

Why JSF calls getters multiple times

primefaces数据表无法正常工作

1 个答案:

另见：