primefaces datatable not working properly - jsf

Question

Following XHTML code for primefaces datatable.
<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>
Following managed beans code for transactionTable :
#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();
}
When I add new record in HTML table it will display in transactionTable when click on "Save New Invoice".
Its work first time properly but when I click on radio button and select "Cheque" option new data not display and its replace old data.

Answer 1

You're not supposed to perform business logic in getters/setters.
A normal getter/setter pair looks like this (exactly like as the average IDE would autogenerate for you):
public List<Transaction> getTransactions() {
return transactions;
}
public void setTransactions(List<Transaction> transactions) {
this.transactions = transactions;
}
You should never change them unless you really know what you're doing. In your particular case, the <p:dataTable> calls the getter on every iteration round. You're basically calling the DAO for every single row. This doesn't make sense. This has a huge performance impact if there are lots of records.
In order to preload the data for view, one of the ways is a #PostConstruct method (the bean should preferably be #ViewScoped for this kind of view):
#PostConstruct
public void init() {
transactions = transactionDao.getTransactions(invoices.get(0).getId());
}
In order to save/update the data after edit, just use the action(listener) method.
See also:
Why JSF calls getters multiple times