Displaying Selected Records Below Using Command Button

Scenario:

    I want to retrieve few records from a particular object and to display them in a Page Block Table along with checkbox for each row in a Table .Now,I will select few records from that table and I will display them in below PageBlock Table with the help of Command Button.

VisualForce Page :

 

<apex:page controller="wrapperClassController">
    <apex:form >
         <apex:pageBlock >
            <apex:pageBlockButtons >
                <apex:commandButton value="Process Selected" action="{!processSelected}" rerender="test"/>
            </apex:pageBlockButtons>
        <!-- In our table we are displaying the cContact records -->
            <apex:pageBlockTable value="{!contacts}" var="c" >
                <apex:column >
                    <!-- This is our selected Boolean property in our wrapper class -->
                    <apex:inputCheckbox value="{!c.selected}"/>
                </apex:column>
            <!-- This is how we access the contact values within our cContact container/wrapper -->
                <apex:column value="{!c.con.Name}" />
                <apex:column value="{!c.con.Email}" />
                <apex:column value="{!c.con.Phone}" />
            </apex:pageBlockTable>


        </apex:pageBlock>
        <apex:pageBlock id="test">
        Total No of Selected Records :<apex:outputText value="{!value }"/>
            <apex:pageBlockTable value="{!SelectedContacts}" var="c" >
                <apex:column value="{!c.Name}" />
                <apex:column value="{!c.Email}" />
                <apex:column value="{!c.Phone}" />
            </apex:pageBlockTable>
            
        </apex:pageBlock>
    </apex:form>
</apex:page> 

Apex Class: 

public class wrapperClassController 

{
 //Our collection of the class/wrapper objects cContact 
 public List<cContact> contactList {get; set;}
 public List<Contact> selectedContacts{get;set;}
 public Integer value {get;set;} 

 public List<cContact> getContacts() 

 {
  if(contactList == null) {
   contactList = new List<cContact>();
   for(Contact c : [select Id, Name, Email, Phone from Contact limit 10]) 

   {
   //As each contact is processed we create a new cContact object and add it to the contactList
   contactList.add(new cContact(c));
   }
  }
  return contactList;
 }  

public PageReference processSelected()

 {
  //We create a new list of Contacts that we be populated only with Contacts if they are selected 

   selectedContacts = new List<Contact>();

  //We will cycle through our list of cContacts and will check to see if the selected 

  //property is set to true, if it is we add the Contact to the selectedContacts list 

   for(cContact cCon : getContacts()) {
    if(cCon.selected == true) {
       selectedContacts.add(cCon.con);
        }
    }
   value = selectedContacts.size();
   System.debug('printing listcontc'+selectedContacts.size());
   // Now we have our list of selected contacts and can perform any type of logic we want,

   // sending emails, updating a field on the Contact, etc 

   return null;

 }
    
public List<Contact> getSelectedContacts()

{
 System.debug('printing listcontc inside get'+selectedContacts.size());
 if(selectedContacts.size()>0)
     return selectedContacts;
 else return null;
}

 //This is our wrapper/container class. A container class is a class,a data structure,or an

 //abstract data type whose instances are collections of other objects. In this example a 

 //wrapper class contains both the standard salesforce object Contact and a Boolean value 

public class cContact 

{
 public Contact con {get; set;}
 public Boolean selected {get; set;}
 //This is the contructor method. When we create a new cContact object we pass a Contact 

 //that is set to the con property. We also set the selected value to false 

 public cContact(Contact c) {
            con = c;
            selected = false;
        }
    }
}