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Jsf Data table values are coming as null

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posted 11 years ago

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I am totally new to JSF and as an exercise i was creating a sample application. In this application once login is complete a data table will be populated with dynamic values(for the time being it is junk values). I have been able to do the navigation and even the datatable shows upto the right number of rows however no values are shown in the data table. Please help , even after reading several solutions(most of which are pretty much similar to what i have done) i am clueless.

The flow is index.jsp ---on login ----> LoginSucces.jsp

code for index.jsp is

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ page contentType="text/html;charset=windows-1252"%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<f:view>
  <html>
    <head>
      <meta http-equiv="Content-Type"
            content="text/html; charset=windows-1252"/>
      <title>Login Page</title>
    </head>
    <body>
      <h:form binding="#{indexBean.indexForm}" id="indexForm"
              title="Login Page">
        <table border=0 align=center>
          <tr>
            <td>
              <h:outputLabel value="Account Number"
                             
                             id="outputLabel2"/>
            </td>
            <td>
              <h:inputText binding="#{indexBean.accountNumber}"
                           id="accountNumber" size="10" maxlength="10"
                           validator="#{indexBean.checkValidAccountNumber}"
                           validatorMessage="Account Number Invalid"/>
            </td>
          </tr>
           
          <tr>
            <td>
              <h:outputLabel value="Password"
                             
                             id="outputLabel3"/>
            </td>
            <td>
              <h:inputSecret binding="#{indexBean.password}" id="password"
                             size="10" maxlength="10"/>
            </td>
          </tr>
        </table>
        <table align="center" cellpadding="0" cellspacing="0">
        <tr>
        <td>
              <h:commandButton value="Login"
                               binding="#{indexBean.loginButton}"
                               id="loginButton"
                               action="#{indexBean.loginButton_action}"/>
            </td>
        </tr>
        </table>
      </h:form>
    </body>
  </html>
</f:view>
<%-- oracle-jdev-comment:auto-binding-backing-bean-name:indexBean--%>

the faces-config.xml is

<?xml version="1.0" encoding="windows-1252"?>
<faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee">
  <managed-bean>
    <managed-bean-name>indexBean</managed-bean-name>
    <managed-bean-class>trialproject.backing.bean.IndexBean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    
  </managed-bean>
  <managed-bean>
    <managed-bean-name>LoginPage</managed-bean-name>
    <managed-bean-class>trialproject.backing.bean.LoginPage</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    
  </managed-bean>
  <navigation-rule>
  <navigation-case>
  <from-outcome>success</from-outcome>
  <to-view-id>/pages/LoginSuccess.jsp</to-view-id>
  </navigation-case>
  <navigation-case>
  <from-outcome>failure</from-outcome>
  <to-view-id>/pages/index.jsp</to-view-id>
  </navigation-case>
  </navigation-rule>
  <managed-bean>
    <managed-bean-name>LoginSuccessBean</managed-bean-name>
    <managed-bean-class>trialproject.backing.bean.LoginSuccessBean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    
  </managed-bean>
</faces-config>

the code for LoginSuccess.jsp is

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ page contentType="text/html;charset=windows-1252"%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<f:view>
  <html>
    <head>
      <meta http-equiv="Content-Type"
            content="text/html; charset=windows-1252"/>
      <title>LoginSuccess</title>
    </head>
    <body>
      <h:form binding="#{LoginSuccessBean.loginSuccessForm}" id="loginSuccessForm">
        <h:outputLabel value="Welcome #{indexBean.accountNumber.value} "
                       binding="#{LoginSuccessBean.outputLabel1}"
                       id="outputLabel1"/>
     <p/>
     <p/>
     <br/>
     <br/>
     <h:dataTable value="#{indexBean.dataList}" var="data" first="0" bgcolor="#F1F1F1" border="1" cellpadding="5" cellspacing="0" >
     <h:column>
     <f:facet name="header">
     <h:outputText value="Account Id" />
     </f:facet>
     <h:inputText value="#{data.accountId}" readonly="true"/>
     </h:column>
     
          <h:column>
     <f:facet name="header">
     <h:outputText value="Account Nick Name" />
     </f:facet>
       <h:inputText value="#{data.accountNickname}" readonly="true"/>
     </h:column>
     
          <h:column>
     <f:facet name="header">
     <h:outputText value="Customer Name" />
     </f:facet>
         <h:inputText value="#{data.customerName}" readonly="true"/> 
     </h:column>
     
     
          <h:column>
     <f:facet name="header">
     <h:outputText value="Customer Sex" />
     </f:facet>
     <h:inputText value="#{data.customerSex}" readonly="true"/> 
     </h:column>
     
     </h:dataTable>
      </h:form>
    </body>
  </html>
</f:view>
<%-- oracle-jdev-comment:auto-binding-backing-bean-name:LoginSuccessBean--%>

most importantly the code for managed bean for the index.jsp is IndexBean.java the code for whicih is

package trialproject.backing.bean;

import javax.faces.component.UIComponent;
import javax.faces.component.html.HtmlCommandButton;
import javax.faces.context.FacesContext;
import javax.faces.component.html.HtmlForm;
import javax.faces.component.html.HtmlInputSecret;
import javax.faces.component.html.HtmlInputText;

import dataModel.Account;

import java.util.ArrayList;
import java.util.List;

import trialproject.backing.bean.LoginSuccessBean;
import java.util.List;
public class IndexBean {
    private HtmlCommandButton loginButton;
    private HtmlInputText accountNumber;
    private HtmlInputSecret password;
    private HtmlForm indexForm;
    
    private static final String ACCOUNT_NICK_NAME = "ACCOUNT OF SOMAK";
    private static final String CUSTOMER_NAME = "SOMAK";
    private static final String CUSTOMER_SEX = "M";

private List<Account> dataList;
    public IndexBean() {

}

public void checkValidAccountNumber(FacesContext facesContext,
                                        UIComponent uIComponent,
                                        Object object) {
        // Add event code here...
    }

public void setDataList(List<Account> dataList) {
        this.dataList = dataList;
        for (Account account : dataList) {
            System.out.println("account id -->" + account.getAccountId());
            System.out.println("account nickname -->" +
                               account.getAccountNickname());
            System.out.println("accountsex -->" + account.getCusomterSex());
            System.out.println("cus name-->" + account.getCustomerName());
        }
    }

public List<Account> getDataList() {
        for (Account account : dataList) {
            System.out.println("inside get method account id -->" + account.getAccountId());
            System.out.println("inside get method account nickname -->" +
                               account.getAccountNickname());
            System.out.println("inside get method accountsex -->" + account.getCusomterSex());
            System.out.println("inside get method cus name-->" + account.getCustomerName());
        }
        return dataList;
    }
    public Object loginButton_action() {
        List<Account> dataList = new ArrayList<Account>();
        String accountNumber = (String)getAccountNumber().getValue();
        String password = (String)getPassword().getValue();
        System.out.println("\n the accountnumber is ---" + accountNumber);
        System.out.println("\n the password is --->" + password);
        if (accountNumber.endsWith("121") && password.endsWith("121")) {
            for (int n = 1; n <= 10; n++) {
                Account account = new Account();
                account.setAccountId(accountNumber);
                account.setAccountNickname(ACCOUNT_NICK_NAME + n);
                account.setCusomterSex(CUSTOMER_SEX);
                account.setCustomerName(CUSTOMER_NAME + n);
                dataList.add(account);
            }
          for(Account account: dataList) {
            System.out.println("during calling account id -->"+account.getAccountId());
              System.out.println("during calling account nickname -->" + account.getAccountNickname());
              System.out.println("during calling accountsex -->" + account.getCusomterSex());  
            System.out.println("during calling cus name-->"+account.getCustomerName()); 
          }
            this.setDataList(dataList);
            return "success";
        } else
            return "failure";
    }

public void setAccountNumber(HtmlInputText accountNumber) {
        this.accountNumber = accountNumber;
    }

public HtmlInputText getAccountNumber() {
        return accountNumber;
    }

public void setPassword(HtmlInputSecret password) {
        this.password = password;
    }

public HtmlInputSecret getPassword() {
        return password;
    }

public void setIndexForm(HtmlForm indexForm) {
        this.indexForm = indexForm;
    }

public HtmlForm getIndexForm() {
        return indexForm;
    }

public void setLoginButton(HtmlCommandButton loginButton) {
        this.loginButton = loginButton;
    }

public HtmlCommandButton getLoginButton() {
        return loginButton;
    }
}

Account.java is a simple pojo

package dataModel;

public class Account {
    
    private String accountId;
    private String accountNickname;
    private String customerName;
    private String cusomterSex;
    public Account() {
        super();
    }

public Account(String accountId, String accountNickname,
                   String customerName, String cusomterSex) {
        super();
        this.accountId = accountId;
        this.accountNickname = accountNickname;
        this.customerName = customerName;
        this.cusomterSex = cusomterSex;
    }

public void setAccountId(String accountId) {
        this.accountId = accountId;
    }

public String getAccountId() {
        return accountId;
    }

public void setAccountNickname(String accountNickname) {
        this.accountNickname = accountNickname;
    }

public String getAccountNickname() {
        return accountNickname;
    }

public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }

public String getCustomerName() {
        return customerName;
    }

public void setCusomterSex(String cusomterSex) {
        this.cusomterSex = cusomterSex;
    }

public String getCusomterSex() {
        return cusomterSex;
    }
}

What am i doing wrong? Is there some problem with the scoping? during the rendering phase are the values getting reset to null ? if so , how come onve invoked thescreen shows right number of rows for the table.

I apologize before hand for the rudimentary approach I have taken above, i am still learning. I would be garteful for any help.

Tim Holloway

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posted 11 years ago

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Actually, that was a bit more information than I could easily read on-screen.

But unless I missed the forest for the trees, you're attempting to supply the dataTable control with data straight from a list of data rows.

JSF doesn't work that way. The dataTable and select controls require their corresponding Model data to be encapsulated in a class that facilitates proper operation of the associated tag's Controller.

Specifically, a dataTable cannot be supplied from a List, it has to be modelled by a javax.faces.DataModel.

There are several classes for this, depending on how the underlying data is supplied. In your case, use the ListDataModel.

It's easy to instantiate such an object. Just supply your List as an argument to the ListDataModel constructor. Or add/replace it after the fact using the setWrappedData method.

The DataModel cannot be dynamically created by a "get" method because it contains the ongoing context used by the Controller to enumerate the rows of the table. In other words, it should be a fixed property of the backing bean class. Create it once and return that object on "get" requests for the table model. Also, the backing bean containing the table model has to be at least View scope (JSF2) or Session scope (JSF 1). Request scope doesn't work except for display-only purposes. If you intend putting input controls or commandlinks in the dataTable, that's not sufficient.

Sometimes the only way things ever got fixed is because people became uncomfortable.

Stanley Walker

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Posts: 101

posted 11 years ago

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Thank you Tim for your reply.I read it multiple times and tell me if I am right in my analysis

1. backing bean will have a field of type listDataModel, along with its getter setters.
2. in jsf i will have <h: data Table value="#{bakcingbean.listDataModelName}"
3. listDataModel has to be created using the list as an argument.

Is that right? I do have to do any further?

Tim Holloway

Saloon Keeper

Posts: 25453

178

I like...

posted 11 years ago

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Stanley Walker wrote:Thank you Tim for your reply.I read it multiple times and tell me if I am right in my analysis

1. backing bean will have a field of type listDataModel, along with its getter setters.
2. in jsf i will have <h: data Table value="#{bakcingbean.listDataModelName}"
3. listDataModel has to be created using the list as an argument.

Is that right? I do have to do any further?

Try it and see!

Sometimes the only way things ever got fixed is because people became uncomfortable.

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