<apex:page controller="AccountSelectClassController" sidebar="false">
    <script type="text/javascript">
        function selectAllCheckboxes(obj,receivedInputID){
            var inputCheckBox = document.getElementsByTagName("input");                  
            for(var i=0; i<inputCheckBox.length; i++){          
                if(inputCheckBox[i].id.indexOf(receivedInputID)!=-1){                                     
                    inputCheckBox[i].checked = obj.checked;
                }
            }
        }
    </script>
    <apex:form >
        <apex:pageBlock >
 <apex:inputText value="{!searchtext1}" label="Search" />
				<apex:pageBlockButtons >
                <apex:commandButton value="search" action="{!search}" rerender="table"/>
                     <apex:commandButton value="Show Selected contacts" action="{!processSelected}" rerender="table2"/>
            </apex:pageBlockButtons>
	           
             
            <apex:pageblockSection title="All Contacts" collapsible="false" columns="2">
             
                <apex:pageBlockTable value="{!wrapContactList}" var="accWrap" id="table" title="All Contacts">
                    <apex:column >
                        <apex:facet name="header">
                            <apex:inputCheckbox onclick="selectAllCheckboxes(this,'inputId')"/>
                        </apex:facet>
                        <apex:inputCheckbox value="{!accWrap.selected}" id="inputId"/>
                    </apex:column>
                    <apex:column value="{!accWrap.con.id}" />
                    <apex:column value="{!accWrap.con.name}" />
                    <apex:column value="{!accWrap.con.Phone}" />
                </apex:pageBlockTable>         
             
            </apex:pageblockSection>
             <apex:pageblockSection title="selected contacts" collapsible="false" columns="2">
             <apex:pageBlockTable value="{!selectedcontacts}" var="c" id="table2" title="Selected Contacts">
                    <apex:column value="{!c.id}" headerValue=" id"/>
                    <apex:column value="{!c.Name}" headerValue="name"/>
                    <apex:column value="{!c.Phone}" headerValue="Phone"/>
                </apex:pageBlockTable>
            </apex:pageblockSection>
        </apex:pageBlock>
                       
    </apex:form>
   
</apex:page>

public class AccountSelectClassController{
//Our collection of the class/wrapper objects wrapAccount 
    public List<wrapContact> wrapContactList {get; set;}
    public List<contact> selectedcontacts{get;set;}
    public string searchtext1{get;set;}
     
    public void search(){
        if(wrapContactList == null) {
            wrapContactList = new List<wrapContact>();
            for(Contact a: [select Id, name, Phone from contact where lastname like :searchtext1 ]) {
                // As each Account is processed we create a new wrapAccount object and add it to the wrapAccountList
                wrapContactList.add(new wrapContact(a));
            }
        }
    }
 
    public void processSelected() {
    selectedcontacts = new List<contact>();
 
        for(wrapContact wrapContactObj : wrapContactList) {
            if(wrapContactObj.selected == true) {
                selectedcontacts.add(wrapContactObj.con);
            }
        }
    }
 
 
    // 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 Account and a Boolean value
    public class wrapContact {
        public contact con {get; set;}
        public Boolean selected {get; set;}
 
        //This is the contructor method. When we create a new wrapAccount object we pass a Account that is set to the acc property. We also set the selected value to false
        public wrapContact(contact a) {
            con = a;
            selected = false;
        }
    }
}