<lightning:datatable keyField=  "id" 
	    							data="{! v.Artifact }" 
	    							columns="{! v.columns }" 
	    							selectedRows="{! v.selectedRows }"
	    							showRowNumberColumn="true" 
	    							onrowselection="{!c.UpdateSelectedRows}"/>

UpdateSelectedRows: function(component,event,helper){
    	let selectedRows = event.getParam('selectedRows');
    	let setRows = [];
    	for (let i = 0; i < selectedRows.length; i++){
    		setRows.push(selectedRows[i].component.get('v.recordId'));

    	}
    	console.log('zzzzzzz ',setRows);
    	//component.set('v.rowsSelected',setRows);

    },

<apex:pageBlockSection id="FolderName" collapsible="true" title="Folder">
				<apex:repeat value="{!foMapNames}" var="fokey">
					<apex:commandLink value="{!foMapNames[fokey]}" action="{!folderIn}" reRender="none">
						<apex:param value="{!fokey}" assignTo="{!foId}"/>
					</apex:commandLink>
					<br/>
				</apex:repeat>
			</apex:pageBlockSection>

public class GDrive {
	public static String AccessToken;

	public GDrive(){
		System.debug('GDrive constructor called ');
	}

	public PageReference authentication(){
		System.debug('Authentication called');
		PageReference pg = GoogleDriveHelper.DriveAuth();
		return pg;
	}

	public void Files(){
		System.debug('Gdrive access token in gd is '+GDrive.AccessToken);
		System.debug('Files called in GDrive');
		//GoogleDriveHelper.AccessToken();
		//list<String> fList = new list<String>();
		/*String fList = GoogleDriveHelper.displayFiles();
		System.debug('>>> l is ' + fList);
		//return fList;*/
	}
}

public class GoogleDriveHelper {
	// Stores authorization code.
	private static String code;
    //Client ID.
    private static string key = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com';
    //Client secret key.
    private static string secret = 'xxxxxxxxxxxxxxxxxxxxxxxxxxx';
    // Url to be redirected when authentication is done.
    private static string redirect_uri = 'https://c.ap5.visual.force.com/apex/googleDrive';
    private static String access_token;
    public static list<String> files;
    public GoogleDriveHelper()
    {
    	System.debug('Constructor of Helper class called ');
    	/*//code = ApexPages.currentPage().getParameters().get('code');
    	System.debug('constructor for helper class called');
        
        //Get the access token once we have code
        if(code != '' && code != null)
        {
            AccessToken() ;
        }*/
    }
    
    public static PageReference DriveAuth()
    {
        //Authorization
        code = ApexPages.currentPage().getParameters().get('code');
        if(code != '' && code != null){
        	System.debug('<<>>>><');
        	GDrive.AccessToken = GoogleDriveHelper.AccessToken();
        	System.debug('GDrive.AccessToken is '+GDrive.AccessToken);
        	return null;
        }
        else{
        	PageReference pg = new PageReference(GoogleDriveAuthUri (key , redirect_uri)) ;
       		return pg;
        }
        
    }
    
    // To redirect to OAuth server, google drive api here.
    public static String GoogleDriveAuthUri(String Clientkey,String redirect_uri)
    {
    	System.debug('Entered authorization ');
        String key = EncodingUtil.urlEncode(Clientkey,'UTF-8');
        String uri = EncodingUtil.urlEncode(redirect_uri,'UTF-8');
        String authuri = '';
        // Call the Google OAuth 2.0 endpoint directly, you'll generate a URL and set the parameters on that URL.
        authuri = 'https://accounts.google.com/o/oauth2/auth?'+
        'client_id='+key+
        '&response_type=code'+
        '&scope=https://www.googleapis.com/auth/drive'+	//Scope to access data on drive. This gives full access
        '&redirect_uri='+uri+
        '&state=security_token%3D138r5719ru3e1%26url%3Dhttps://oa2cb.example.com/myHome&'+
        //'&login_hint=jsmith@example.com&'+
        'access_type=offline';	//Indicates whether your application can refresh access tokens when the user is not present at the browse
        return authuri;
    }
    
    
    public static String AccessToken()
    {
    	code = ApexPages.currentPage().getParameters().get('code');
        //Getting access token from google drive api app
        System.debug('code in access_token is ' + code);
        HttpRequest req = new HttpRequest();
        req.setMethod('POST');	//http method of POST is used.
        req.setEndpoint('https://accounts.google.com/o/oauth2/token');	//URL from which you have to extract resources.
        req.setHeader('content-type', 'application/x-www-form-urlencoded');	//file type:application, extension:x-www-form-urlencoded
        String messageBody = 'code='+code+'&client_id='+key+'&client_secret='+secret+'&redirect_uri='+redirect_uri+'&grant_type=authorization_code';
        req.setHeader('Content-length', String.valueOf(messageBody.length()));
        req.setBody(messageBody);
        req.setTimeout(60*1000);	//Time out is for 60 secs.

        Http h = new Http();
        String resp;
        HttpResponse res = h.send(req);
        System.debug('access token request is ' + res);
        resp = res.getBody();
        Map<String,object> m = (Map<String, Object>)Json.deserializeuntyped(resp);	// Stores JSON string values in a map
        access_token = (String)(m.get('access_token'));	//Retrives the value of access token from map and stores it.
        //We have to pass this access token everytime when a hit is made.
        System.debug(' access Token is ' + access_token);
        return access_token;
        
   	}

   	public static String displayFiles(){
   		System.debug('access_token is >>>> '+ access_token);
   		HttpRequest req = new HttpRequest();
   		req.setMethod('GET');	// Http method of get is used here.
   		// setEndPoint url parameters are passed 
   		req.setEndpoint('https://www.googleapis.com/drive/v3/files?corpora=user,allTeamDrives&includeTeamDriveItems=true&supportsTeamDrives=true');
   		// to pass access token.
   		System.debug('AccessToken in disp is ' + access_token);
   		req.setHeader('Authorization', 'Bearer ' + access_token);
   		req.setTimeout(60*1000);

   		Http h = new Http();
   		String resp;
   		HttpResponse res = h.send(req);
   		System.debug('Send request is ' + res);
   		resp = res.getBody();	// JSON string values are returned here.
   		Map<String,object> m = (Map<String, Object>)Json.deserializeuntyped(resp);
   		System.debug(m.size());
   		String str = (String)m.get('files.Name');
   		//files = str.split(',');
   		//System.debug('?????? '+files[0]);
   		System.debug(resp);
   		return str;
   	}
}

global class ContactBatch implements Database.Batchable<sObject>{
}

global class ContactBatch implements Batchable{
}

global class BatchNSchedulable implements Database.Batchable<sObject>{
	global list<contact> con=new list<contact>();
	String query = 'SELECT id,name,status__c FROM contact WHERE CreatedDate= Yesterday';
	global Database.QueryLocator start(Database.BatchableContext bc){
		System.debug('In the start');
		 return (Database.getQueryLocator(query));
	}
	global void execute(Database.BatchableContext bc,list<sObject> li){
		System.debug('In the execute');
		con = (list<contact>)li;
		System.debug(con.size());	
		for(contact ct:con){
			ct.put('status__c','None');
		}
		System.debug('con in execute is '+con);
	}
	global void finish(Database.BatchableContext bc){
		System.debug('con is '+con);
		update con;
		System.debug('In the finish');
	}

}

<apex:actionFunction action="{!docReady}" name="funAtLast" reRender="form,alpha,table,button"/>

public class PaginationForComponent {
    public PaginationForComponent(){
    allContactList = new list<wrapper>();
    myOrder = 'desc';
    sortField='name';
    PageNumber = 1;
    alphabet = new list<string>{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','Others','All'};
    RecordsPerPageslist = 10;
    System.debug('constructor called');
    csv='';
  }
  Boolean lstNamePresent=false;
  public String objName{get;set;}
  public String fieldNames{get;set;}
  list<sObject> con = new list<sObject>();
  public String alphaSearchConct{get;set;}
  public string msg {get;set;}
  public Map<id,Boolean> m = new Map<id,boolean>(); 
  list<sObject> sortedList;
  public String myOrder{get;set;}                 // Ascending or Descending order of sorting
  public String sortField{get;set;}               // Field by which sorting should be done
  public boolean selectAll{get;set;}
  public list<String> alphabet{get;set;}
  public list<sObject> cont;
  public list<wrapper> allContactList{get;set;}
  public list<wrapper> ct = new list<wrapper>();
  public list<String> query;
  public String csv{get;set;}
 
  public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
    get{
        if(stdSetController==null){
            //con = Database.query('SELECT '+ fieldNames+' FROM '+ objName );//del it from here update con from script n return allContactList by filling it from there only
            System.debug('con in ssc is : ' + con);
            stdSetController = new ApexPages.StandardSetController(con);
        }
        stdSetController.setPageSize(RecordsPerPageslist);        //Limiting Number of records to be displayed per page 
        System.debug('stdSetController called and fieldNames are : ' + allContactList);
        return stdSetController;   
    }
    set;
  }
  public void SelectedListContacts(){         // Select contacts and save them in a map  
    for(wrapper wc:allContactList){
        m.put(wc.con.id,wc.isSelected);
        if(wc.isSelected==false){
            selectAll=false;
         }
    }
  }
  public void SelectedAllContacts(){          //To select all contacts in a page
    System.debug(selectAll);
    allContactList.clear();
    for(sObject c:(list<sObject>)stdSetController.getRecords()){
        allContactList.add(new wrapper(c));
    }
    if(selectAll==true){
        for(wrapper wc:allContactList){
            m.put(wc.con.id,wc.isSelected=true);
    }
   }
    else{
      for(wrapper wc:allContactList)
          m.put(wc.con.id,wc.isSelected=false);
   }
  }
  public String[] getqueryList(){
    query = fieldNames.split(',');
    for(String s:query){
      if(s=='lastname'){
        lstNamePresent=true;
      }
  }

}
  public list<wrapper> getWrapperContacts(){      //List of wrapper class to display in table
    return allContactList;
  }

  public Integer stdSize(){
    Integer i = stdSetController.getRecords().size();
    return i;
  }

  public void docReady(){
    con = Database.query('SELECT '+ fieldNames+' FROM '+ objName );
    System.debug('docReady con is ' + con);
    for(sObject c:(list<sObject>)stdSetController.getRecords())
          allContactList.add(new wrapper(c));
    System.debug('docReady allContactList is ' + allContactList);
  }

public void submit() {
    Set<id> ids = new set<id>();
    for(id i:m.keySet()){
        if(m.get(i)==true){ 
        ids.add(i);
        }
    }
    String queryStr = 'SELECT ' + fieldNames + ' FROM ' + objName + ' WHERE id IN :ids';
    sObject[] c = Database.query(queryStr);
    String temp = '';
    for(Integer i=0;i<c.size();i++){
    for(String s: query){
       temp = String.valueOf((c[i].get(s)));
       // System.debug('before escape csv temp is ' + temp);
        if(temp!=null){
            temp = temp.escapeCsv();}
       // System.debug('temp after escapeCsv() is ' + temp);
        csv += temp;
       // System.debug('str is '+str);
        csv += ', ';
    }
  }
}
// To convert to CSV file
 
public String getgenerateCSV() {
  System.debug('csv is :' + csv);
  return csv;
}
/*public String[] getqueries(){
  System.debug(csvQuery);
  return csvQuery;
}*/
  public class wrapper{
    public boolean isSelected{get;set;}  
    public sObject con{get;set;}  
    public   wrapper(sObject con){
            //System.debug('constructor of wrapper class called ');
            isSelected = false;
            this.con = con;
        }
  }
}

<apex:component controller="PaginationForComponent" allowDml="true">

    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script>
    	function SuccessFailure(msg) {
        	if(msg == '') {
            	window.top.location.reload()
            } else {
            	alert(msg);
            }
        }
        function cannotFind(msg){
            if(msg!=null)
                alert(msg);
        }
        $(document).ready(function(){
            funAtLast();
        });
    </script>
    <apex:attribute name="objectName" description="The object's name" type="String" required="true" assignTo="{!objName}"/>
    <apex:attribute name="fieldName" description="Fields to be displayed" type="String" required="true" assignTo="{!fieldNames}"/>
    <apex:outputPanel id="form">
        <apex:actionFunction action="{!docReady}" name="funAtLast" reRender="form,alpha,table,button"/>
        <style>
    .bPageBlock .pbBody .dataCol {
        border:0px;
    }
    .bPageBlock .pbBody .labelCol { 
        border:0px;
    }
	</style>
       <!-- <apex:commandButton value="Process" reRender="form,alpha,table,button"/>-->
        <apex:outputPanel rendered="{!allContactList.size!=0}" id="page">
            <!-- For alphabetic search-->
                <div align="right" >
                        <apex:repeat value="{!alphabet}" var="alph" >
                            <apex:commandLink value="{!alph}  " action="{!alphaSearch}" oncomplete="cannotFind('{!msg}');" reRender="table,button" id="cs" > &ensp;
                                <style type="text/css">
                                    #cs:hover{
                                        background-color: #b3ffff;
                                    }
                                </style>
                                <apex:param name="a" value="{!alph}" assignTo="{!alphaSearchConct}"/>
                            </apex:commandLink>
                        </apex:repeat>
                </div>
            <apex:pageBlock id="table">
                <!-- To delete selected records-->
                <apex:commandButton action="{!DelSelected}" value="Delete Selected" oncomplete="SuccessFailure('{!msg}');"/>
                <!-- Button for csv download -->
                <apex:commandButton action="{!submit}" value="Download CSV" reRender="none"/>
                <apex:pageMessages rendered="true" id="Msg"/>
                <apex:PageBlockTable value="{!WrapperContacts}" var="contacts">
                    <!-- To Edit and Delete a record -->
                   <apex:column headerValue="Action">
                        <apex:outputLink value="{!URLFOR($Action[objectName].Edit,contacts.con.id)}">
                            Edit |
                        </apex:outputLink>
                        <apex:outputLink value="{!URLFOR($Action[objectName].Delete,contacts.con.id)}"> 
                            Del |
                        </apex:outputLink>
                    </apex:column>
                    <apex:column >
                    <apex:facet name="header">
                            <apex:inputCheckbox value="{!selectAll}">  
                                <apex:actionSupport event="onclick" action="{!SelectedAllContacts}" reRender="table"/>
                                </apex:inputCheckbox>  
                            </apex:facet>
                        <apex:inputCheckbox value="{!contacts.isSelected}">
                            <apex:actionSupport event="onclick" action="{!SelectedListContacts}" reRender="none" />
                        </apex:inputCheckbox> 
                    </apex:column>
                    <apex:repeat value="{!queryList}" var="fldNames">
                        <apex:column >
                            <apex:facet name="header">
                                <apex:commandLink value="{!fldNames}" action="{!toggleSort}" reRender="table">
                                    <apex:param name="sortField" value="{!fldNames}" assignTo="{!sortField}" />
                                    <apex:param name="myOrder" value="{!IF(myOrder == 'DESC', 'ASC','DESC')}" assignTo="{!myOrder}" />
                                </apex:commandLink>
                            </apex:facet>
                            {!contacts.con[fldNames]}
                        </apex:column>
                    </apex:repeat>
                </apex:PageBlockTable>
            </apex:pageBlock>
            <apex:outputPanel id="button"> 
                <div align = "center" >
                    <!-- To return to first page of records-->
                    <apex:commandButton action="{!first}" value="<<" title="First Page" disabled="{!!HasPrevious}" reRender="table,button"/>
                    <!-- To return to Previous page of records-->
                    <apex:commandButton action="{!previous}" value="Previous" disabled="{!!HasPrevious}" reRender="table,button"/>
                    <!-- To return to next page of records-->
                    <apex:commandButton action="{!next}" value="Next >" disabled = "{!!HasNext}" reRender="table,button"/>
                    <!-- To return to last page of records-->
                    <apex:commandButton action="{!last}" value=">>" title="Last Page" disabled="{!!HasNext}" reRender="table,button"/>
                    <!-- InputText to display current page and to navigate to any page number, At righmost side of page-->
                    <span style="float:right">
                        <apex:outputLabel value="Page ">
                        </apex:outputLabel>
                         <!-- To navigate to the page--> 
                        <apex:InputText value="{!PageNumber}" maxLength="4" size="1">
                        <apex:actionSupport event="onchange" action="{!NavigateByText}"  reRender="table,button"/>
                        </apex:InputText>
                         <!-- The above action support is not working-->         
                        <apex:outputLabel value=" of {!TotalPages}">
                        </apex:outputLabel>
                    </span>
                    <!-- To display a list for number of records to be selected per page-->
                    <span style = "float:left">
                        <apex:SelectList value="{!RecordsPerPageslist}" size="1" >
                            <apex:selectOptions value="{!RecordsPerPageOptionList}">    
                            </apex:selectOptions>
                            <apex:actionSupport event="onchange" action="{!ChangeNumberOfRecordsPerPage}" reRender="table,button"/>
                        </apex:SelectList>
                    </span>
                </div>
            </apex:outputPanel>    
        </apex:outputPanel> 
    </apex:outputPanel>
</apex:component>

id i = 0037F00000M6MCHQA3;
String fieldNames='name,id';
String objName = 'contact';
String queryStr = 'SELECT ' + fieldNames + ' FROM ' + objName + ' WHERE id IN :(\'i\')';
System.debug(queryStr);

public class PaginationForComponent {
  public PaginationForComponent(){
    allContactList = new list<wrapper>();
    myOrder = 'desc';
    sortField='name';
    PageNumber = 1;
    alphabet = new list<string>{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','Others','All'};
    RecordsPerPageslist = 10;
    System.debug('constructor called');
  }
  Boolean lstNamePresent=false;
  public String objName{get;set;}
  public String fieldNames{get;set;}
  list<sObject> con = new list<sObject>();
  public String alphaSearchConct{get;set;}
  public string msg {get;set;}
  public Map<id,Boolean> m = new Map<id,boolean>(); 
  list<sObject> sortedList;
  public String myOrder{get;set;}                 // Ascending or Descending order of sorting
  public String sortField{get;set;}               // Field by which sorting should be done
  public boolean selectAll{get;set;}
  public list<String> alphabet{get;set;}
  public list<sObject> cont;
  public list<wrapper> allContactList{get;set;}
  public list<wrapper> ct = new list<wrapper>();
  public list<wrapper> csvList = new list<wrapper>();
  public list<String> query = new list<String>();
  public list<String> csvQuery;
public Pagereference submit() {
    csvList = new list<wrapper>();
    csvQuery = new list<String>();
    try {
    for (id i: m.keySet()) {
      System.debug('id is '+i);
      if (m.get(i) == true) {
        sObject c = Database.query('SELECT ' + fieldNames + ' FROM ' + objName + ' WHERE id= :i');
        ct.add(new wrapper(c));
        System.debug('ct is '+ ct);
      }
     }
    } 
    catch (System.QueryException e) {
     System.debug('Error while generating csv file ' + e);
    }
    csvList.addAll(ct);
    csvQuery.addAll(query);
    System.debug('csv list earlier ' + csvList);
    Pagereference pgReference = Page.ConvertToCSVController;
    PgReference.setRedirect(false);
    return pgReference;
    }
public list < wrapper > getgenerateCSV() {
    System.debug('csv list is :' + csvList);
    return csvList;
  }
  public String[] getqueries(){
    return csvQuery;
  }
    public class wrapper{
      public boolean isSelected{get;set;}  
      public sObject con{get;set;}  
      public   wrapper(sObject con){
              //System.debug('constructor of wrapper class called ');
              isSelected = false;
              this.con = con;
          }
    }
  }

<apex:page controller="PaginationForComponent" contentType="application/vnd.ms-excel#contacts.xls" readOnly="True">
<apex:form id="form">
    <apex:pageBlock >
        <apex:pageBlockTable value="{!generateCSV}" var="csv">
            <apex:repeat value="{!queries}" var="fldNames">
                <apex:column value="{!csv.con[fldNames]}"/> 
            </apex:repeat>
        </apex:pageBlockTable> 
    </apex:pageBlock>
</apex:form>
</apex:page>

<apex:page sidebar="false" controller="t1">
	<apex:form >
	<apex:pageBlock >
		Select Object Name &ensp;&nbsp;
		<apex:SelectList value="{!ObjList}" size="1">
          <apex:selectOptions value="{!objectList}">    
           </apex:selectOptions>
          <!-- <apex:actionSupport event="onchange" action="{!ChangeNumberOfRecordsPerPage}" reRender="table,button"/>-->
        </apex:SelectList>
        <apex:panelBar >
        	<apex:panelBarItem label="Field Values"/>
        	<apex:SelectList value="{!fldList}" multiselect="true">
        		<apex:selectOptions value="{!fieldList}">
        	</apex:selectOptions>
        </apex:SelectList>
    </apex:panelBar>
	</apex:pageBlock>
	</apex:form>
  <!--  <c:Dynamic_pagination objectName="contact" fieldName="Name,Account.name,Title">
    </c:Dynamic_pagination>
-->
</apex:page>

public class t1 {

    public String ObjList{get;set;}
    public String fldList{get;set;}
	public list < SelectOption > getobjectList() { 
        list < SelectOption > options = new list < SelectOption > ();
        for(Schema.SObjectType item : ProcessInstance.TargetObjectId.getDescribe().getReferenceTo()){
            String name = item.getDescribe().getName();
            if(!item.getDescribe().CustomSetting && item.getDescribe().isAccessible() && !name.containsignorecase('orgDeleteRequest') && !name.containsignorecase('Solution') 
                && !name.containsignorecase('StreamingChannel') ){
                options.add(new SelectOption(item.getDescribe().getName(), item.getDescribe().getLabel()));
            }
            options.sort();
        }
        return options;
    }
    public list <SelectOption> getfieldList(){
        list<SelectOption> options = new list<SelectOption>();
        Schema.DescribeSObjectResult[] descResult = Schema.describeSObjects(new String[]{ObjList});
        Map <String,Schema.SObjectField> fldMap = descResult[0].fields.getmap();
        for(String K:fldMap.KeySet()){
            options.add(new SelectOption(K,K));
        }
        options.sort();
        return options;
        //System.debug(Schema.sObjectType.Account.fields.getmap());
    }
}

Schema.sObjectType.Account.fields.getmap()

<apex:component controller="PaginationForComponent" >
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script>
    	function SuccessFailure(msg) {
        	if(msg == '') {
            	window.top.location.reload()
            } else {
            	alert(msg);
            }
        }
        $(document).ready(function(){
            funAtLast();
            alert('document.ready called');
        });
    </script>
    <apex:attribute name="objectName" description="The object's name" type="String" required="true" assignTo="{!objName}"/>
    <apex:attribute name="fieldName" description="Fields to be displayed" type="String" required="true" assignTo="{!fieldNames}"/>
    <apex:form >
        <apex:actionFunction action="{!docReady}" name="funAtLast" reRender="none"/>
        <apex:commandButton value="Process" reRender="form,alpha,table,button"/>
    
    <apex:outputPanel id="form" rendered="{!allContactList.size!=0}">
        <!-- For alphabetic search-->
        <apex:pageBlock id="alpha">
            <div align="right">
                <apex:panelGrid >
                    <apex:repeat value="{!alphabet}" var="alph">
                        <apex:commandLink value="{!alph} | " action="{!alphaSearch}" reRender="table,button">
                            <apex:param name="a" value="{!alph}" assignTo="{!alphaSearchConct}"/>
                        </apex:commandLink>
                    </apex:repeat>
                </apex:panelGrid>
            </div>
        
        </apex:outputPanel>    
    </apex:outputPanel>    
    </apex:form >
</apex:component>

public class PaginationForComponent {
    public String objName{get;set;}
	public String[] fieldNames{get;set;}
	list<sObject> con = new list<sObject>();

	
	public PaginationForComponent(){
		RecordsPerPageslist = 10;
	}

	public String query;
	public String alphaSearchConct{get;set;}
	public string msg {get;set;}
	public Map<id,Boolean> m = new Map<id,boolean>(); 
	list<sObject> sortedList;
	public String myOrder{get;set;}                 // Ascending or Descending order of sorting
	public String sortField{get;set;}               // Field by which sorting should be done
	public boolean selectAll{get;set;}
	public list<String> alphabet{get;set;}
	public list<sObject> cont;
	public list<wrapper> allContactList = new list<wrapper>();
	public void fieldvalues(){
		query = fieldNames[0] + ' , ';
		for(Integer i=1;i<fieldNames.size();i++){
			query = query + fieldNames[i] + ' , ';
		}
		query='SELECT ' + query + ' FROM ' + 'objName';
	}
	public Integer RecordsPerPageslist{ 
        get;
        set{                                                          //To select number of records per page
            if(value!=null){
                this.RecordsPerPagesList=value;
                System.debug('RecordsPerPageList called');
            }
        }       
    }  
    public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
          get{
              if(stdSetController==null){
                    con = Database.query(query);
                    System.debug('con in ssc is : ' + con);
                   stdSetController = new ApexPages.StandardSetController(con);
              }
                stdSetController.setPageSize(RecordsPerPageslist);        //Limiting Number of records to be displayed per page 
                  System.debug('stdSetController called ');
              return stdSetController;   
          }
          set;
      }
    public list<wrapper> getWrapperContacts(){      //List of wrapper class to display in table
       for(sObject c:(list<sObject>)stdSetController.getRecords()){
       		allContactList.add(new wrapper(c));
       }
        return allContactList;
    }

    public class wrapper{
	  public boolean isSelected{get;set;}  
	  public sObject con{get;set;}  
	  public   wrapper(sObject con){
	          System.debug('constructor of wrapper class called ');
	          isSelected = false;
	          this.con = con;
	          }
	          
	      }
}

<apex:component controller="PaginationForComponent" >
    <apex:attribute name="objectName" description="The object's name" type="String" required="true" assignTo="{!objName}"/>
    <apex:attribute name="fieldName" description="Fields to be displayed" type="String[]" required="true" assignTo="{!fieldNames}"/>
    <apex:pageBlock >
        <apex:repeat value="{!getWrapperContacts}" var="repeat">
            <apex:outputText value="{!repeat}">
            
            </apex:outputText>
            
        </apex:repeat>
    
    </apex:pageBlock>
</apex:component>

$(document).ready()

public class PaginationForComponent {
    public String objName{get;set;}
	public String fieldNames{get;set;}
public void getConstructor(){
        System.debug('Field values are '+ fieldNames);
		con = Database.query('SELECT '+ fieldNames +' FROM '+ objName);
        System.debug('Field values are '+ fieldNames);
        System.debug(con);
        myOrder = 'desc';
        sortField='name';
        PageNumber = 1;
        RecordsPerPageslist=10;
        alphabet = new list<string>{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','Others','All'};
        allContactList = new list<wrapper>();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
	}
public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
	        get{
	            if(stdSetController==null){
	                 stdSetController = new ApexPages.StandardSetController(con);
	            }
	              stdSetController.setPageSize(RecordsPerPageslist);        //Limiting Number of records to be displayed per page 
	                System.debug('stdSetController called ');
	            return stdSetController;   
	        }
	        set;
	    }public Integer TotalPages{                                            // Total number of pages as per user selection of Records per page
	        get{
	             System.debug('TotalPages called'); 
	            if(stdSetController.getResultSize() <=10)
	                   this.TotalPages=1;
	              if(Math.Mod(stdSetController.getResultSize() ,stdSetController.getPageSize()) == 0)
	                  this.TotalPages =(stdSetController.getResultSize()/stdSetController.getPageSize());
	              else
	                this.TotalPages = (stdSetController.getResultSize()/stdSetController.getPageSize())+1;
	              //System.Debug(this.TotalPages);
	                return totalpages;
	        }
	        set;
	    }
	public Integer RecordsPerPageslist{ 
        get;
        set{                                                          //To select number of records per page
            if(value!=null){
                this.RecordsPerPagesList=value;
                System.debug('RecordsPerPageList called');
            }
        }       
    }    
}

<apex:component controller="PaginationForComponent" >
    
    <apex:attribute name="objectName" description="The object's name" type="String" required="true" assignTo="{!objName}"/>
    <apex:attribute name="fieldName" description="Fields to be displayed" type="String" required="true" assignTo="{!fieldNames}"/>
    {!objName}
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"> </script>
    <script>
    	function SuccessFailure(msg) {
        	if(msg == '') {
            	window.top.location.reload()
            } else {
            	alert(msg);
            }
        }
    $(document).ready(function(){
        construct();
        });
    </script>
    <apex:form > 
        <apex:actionFunction name="construct" action="{!getConstructor}"/>
.........

<apex:component controller ="PaginationForComponent">
    <apex:attribute name= "objectName" description = "The object's name" type = "String" required = "true" assignTo="{!objName}"/>
    <apex:attribute name= "fieldName" description = "Fields to be displayed" type = "String" required ="true" assignTo="{!fieldNames}"/>
<apex:outputLink value="{!URLFOR($Action."{!objName}".Edit,contacts.con.id)}"> 
                        Edit |
                    </apex:outputlink>
                    <apex:outputLink value="{!URLFOR($Action."{!objName}".Delete,contacts.con.id)}"> 
                        Del |
                    </apex:outputlink>

public class PaginationForComponent {
public String objName{get;set;}
	public String fieldNames{get;set;}
}

String objName = 'Contact';
string alphaSearchConct = 'A';
String fieldNames = 'name,id';
list<sObject> ct = Database.query('SELECT '+ fieldNames +'FROM '+ objName +'WHERE lastname Like:'+alphaSearchConct +'%');

public class ContactListViewController {
    public ContactlistViewController(){
        system.debug('constructor first called');
        RecordsPerPageslist=10;
        allContactList = new list<wrapper>();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
        System.debug('constructor called');
    }
    Map<id,Boolean> m = new Map<id,boolean>();  	 // To store boolean values of checkboxes corrosponding to every contact id
    list<contact> con = [SELECT Name,id,Account.name,Title,Phone,Email FROM Contact];
    public list<wrapper> allContactList;			//Wrapper class object
    
    public list<wrapper> getWrapperContacts(){  	//List of wrapper class to display in table
        return allContactList;
    }
    
    public void getSelectedListContacts(){  		// Select contacts and save them in a map
        for(wrapper wc:allContactList){
            m.put(wc.con.id,wc.isSelected);
        }
        
        System.debug('getSelectedListContacts = '+m);
        
    }
    public void getSelectedAllContacts(){			//To select all contacts in a page
        for(wrapper wc:allContactList){
            m.put(wc.con.id,wc.isSelected=true);
        }
    }
    public void next(){
        System.debug('next');
		allContactList.clear();        
        this.stdSetController.next();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
        }
    }
    public void previous(){
		allContactList.clear();        
        this.stdSetController.previous();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public void last(){
        allContactList.clear();        
        this.stdSetController.last();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public void first(){
        allContactList.clear();        
        this.stdSetController.first();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public boolean getHasNext(){
        return stdSetController.getHasNext();
    }
    public boolean getHasPrevious(){
        return stdSetController.getHasPrevious();
    }
    public list<String> alphabet{
        get{															//To display a list of alphabets on vf page 
            alphabet = new list<string>{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','Others','All'};
       		return alphabet;	 
                }
        set;
    }
    public String alphaSearchConct{get;set;}							// To get commandlink parameter for alphabet selected
    public Pagereference getalphaSearch(){								//To update contact list as per the alphabet selected by the user
        allContactList.clear();
        if (alphaSearchConct=='All'){
            con = [SELECT name,Account.name,Title,Phone,Email FROM contact];
        }
        else{
            	con = [SELECT name,Account.name,Title,Phone,Email FROM contact WHERE lastName Like:alphaSearchConct+'%'];
        }
        ApexPages.StandardSetController ssc = new ApexPages.StandardSetController(con);
        stdSetController= ssc;
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
        system.debug('alphaSearchconct called');
        return null;
    }      
    public Integer PageNumber{
        get{                                                            //To get current page number
  		    System.debug('get of pageNumber called '+ PageNumber);
            this.PageNumber=stdSetController.getPageNumber();   
            return this.PageNumber;
        }
        set{  
            System.debug('set of pageNumber called');
           	this.pageNumber=value;         
    }
        }
    
    public PageReference NavigateByText(){
        
        System.debug('getNavigateByText '+ stdSetController.getPageNumber());
        allContactList.clear();
        this.stdSetController.setPageNumber(PageNumber);
            for(contact c:(list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
            //System.debug(stdSetController.getRecords());
           for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
               System.debug(wc.isSelected);
               System.debug('pageNumber called');
               
    }
        return null;
    }
    public Integer TotalPages{                                            // Total number of pages as per user selection of Records per page
        get{
              if(stdSetController.getResultSize() <=10)
                   this.TotalPages=1;
              if(Math.Mod(stdSetController.getResultSize() ,stdSetController.getPageSize()) == 0)
                  this.TotalPages =(stdSetController.getResultSize()/stdSetController.getPageSize());
              else
                this.TotalPages = (stdSetController.getResultSize()/stdSetController.getPageSize())+1;
              //System.Debug(this.TotalPages);
                return totalpages;
        }
        set;
    }
    public Integer MaxNumberOfRecords{                                    //Maximum number of records in a query list
        get{
             return stdSetController.getRecords().size();
        }
        set;
    }
    public list<SelectOption> getRecordsPerPageOptionList(){              //To display a drop down list on vf page  
            list<SelectOption>  options = new list<SelectOption>();
            options.add(new selectOption('10','10'));
            options.add(new selectOption('25','25'));
            options.add(new selectOption('50','50'));
            options.add(new selectOption('100','100'));
            options.add(new selectOption('200','200'));
            return options;
    }
    public Integer RecordsPerPageslist{ 
        get;
        set{                                                          //To select number of records per page
            if(value!=null){
                this.RecordsPerPagesList=value;
                System.debug('RecordsPerPageList called');
            }
        }       
    }
    public Pagereference getChangeNumberOfRecordsPerPage(){
        allContactList.clear();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
         for(wrapper wc:allContactList)
            wc.isSelected=m.get(wc.con.id);
        return null;
    } 
    public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
        get{
            if(stdSetController==null){
             	 stdSetController = new ApexPages.StandardSetController(con);
            }
              stdSetController.setPageSize(RecordsPerPageslist);        //Limiting Number of records to be displayed per page 
            	System.debug('stdSetController called '+ stdSetController.getPageNumber());
            return stdSetController;   
        }
        set;
    }
    public class wrapper{
      public boolean isSelected{get;set;}
      public Contact con{get;set;}
       
         wrapper(contact con){
            isSelected = false;
            this.con = con;
        }
    }
}

<apex:page controller="ContactListViewController" sidebar="false">
    <apex:form >
        <!-- For alphabetic search-->
        <div align="right">
            <apex:panelGrid >
                <apex:repeat value="{!alphabet}" var="alph">
                    <apex:commandLink value="{!alph} | " action="{!getalphaSearch}" reRender="table">
                        <apex:param name="a" value="{!alph}" assignTo="{!alphaSearchConct}"/>
                    </apex:commandLink>
                </apex:repeat>
            </apex:panelGrid>
        </div>
        <apex:PageBlock id="table">
            <apex:pageMessages />
            <apex:commandButton action="{!getSelectedAllContacts}" value="Select All" reRender="table"/>
            <apex:PageBlockTable value="{!WrapperContacts}" var="contacts" >
                <!-- To display and select Checkboxes-->
                <apex:column >
                    <apex:facet name="header">
                    	<apex:inputCheckbox value="{!contacts.isSelected}">
                        	<apex:actionSupport event="onclick" action="{!getSelectedAllContacts}" reRender="table"/>
                        </apex:inputCheckbox>	
                        </apex:facet>
                    <apex:inputCheckbox value="{!contacts.isSelected}">
                        <apex:actionSupport event="onclick" action="{!getSelectedListContacts}" reRender="table"/>
                    </apex:inputCheckbox>  
                </apex:column>
                <!-- To Edit and Delete a record -->
                <apex:column headerValue="Action">
                    <apex:outputLink value="{!URLFOR($Action.Contact.Edit,contacts.con.id)}"> 
                        Edit |
                    </apex:outputlink>
                    <apex:outputLink value="{!URLFOR($Action.Contact.Delete,contacts.con.id)}"> 
                        Del |
                    </apex:outputlink>
                </apex:column>
                <apex:column headerValue="Name">
                    <apex:outputLink value="/{!contacts.con.id}">
                        {!contacts.con.name}
                    </apex:outputLink>
                </apex:column>
                <apex:column headerValue="Account Name">
                    <apex:outputLink value="/{!contacts.con.account.id}">
                        {!contacts.con.account.name}
                    </apex:outputLink>
                </apex:column>
                <apex:column value="{!contacts.con.Title}"/>
                <apex:column value="{!contacts.con.Phone}"/>
                <apex:column value="{!contacts.con.email}"/>
                <apex:inlineEditSupport />
            </apex:PageBlockTable>
      		</apex:PageBlock> 
        <!-- below code for pagination -->
        <apex:outputPanel id="button"> 
        <div align = "center" >
            <!-- To return to first page of records-->
            <apex:commandButton action="{!first}" value="<<" title="First Page" disabled="{!!HasPrevious}" reRender="table,button"/>
            <!-- To return to Previous page of records-->
            <apex:commandButton action="{!previous}" value="Previous" disabled="{!!HasPrevious}" reRender="table,button"/>
            <!-- To return to next page of records-->
            <apex:commandButton action="{!next}" value="Next >" disabled = "{!!HasNext}" reRender="table,button"/>
            <!-- To return to last page of records-->
            <apex:commandButton action="{!last}" value=">>" title="Last Page" disabled="{!!HasNext}" reRender="table,button"/>
            <!-- InputText to display current page and to navigate to any page number, At righmost side of page-->
            <span style="float:right">
                <apex:outputLabel value="Page ">
                </apex:outputLabel>
                 <!-- To navigate to the page--> 
                <apex:InputText value="{!PageNumber}" maxLength="4" size="1"/>
                <apex:actionSupport event="onchange" action="{!NavigateByText}" reRender="table,button"/>
                <!-- The above action support is not working-->         
                <apex:outputLabel value=" of {!TotalPages}">
                </apex:outputLabel>
            </span>
            <!-- To display a list for number of records to be selected per page-->
            <span style = "float:left">
                <apex:SelectList value="{!RecordsPerPageslist}" size="1" >
                    <apex:selectOptions value="{!RecordsPerPageOptionList}">    
                    </apex:selectOptions>
                    <apex:actionSupport event="onchange" action="{!getChangeNumberOfRecordsPerPage}" reRender="table,button"/>
                </apex:SelectList>
            </span>
        </div>
    </apex:outputPanel>      
    </apex:form>
</apex:page>

public class t1 {
    list<contact> con = [SELECT Name,Account.name,Title,Phone,Email FROM Contact];
    public list<wrapper> allContactList;
    public list<contact> SelectedContact = new list<contact> ();
   
    public list<wrapper> getWrapperContacts(){  
        allContactList = new list<wrapper>();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        return allContactList;
    }

    public void getSelectedListContacts(){
        for(wrapper wc:allContactList){
            System.debug(wc.isSelected+' '+wc.con);
            if(wc.isSelected==true){
                SelectedContact.add(wc.con);
            }
        }
        System.debug(selectedContact);
    }
    public void getSelectedAllContacts(){			//To select all contacts
        for(wrapper wc:allContactList){
            SelectedContact.add(wc.con);
        	//new t1.wrapper().isSelected=true;
        }
    }
     public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
        get{
            if(stdSetController==null){
             	 stdSetController = new ApexPages.StandardSetController(con);
            }
              stdSetController.setPageSize(10);        //Limiting Number of records to be displayed per page 
               return stdSetController;   
        }
        set;
    }
    
    public class wrapper{
      public boolean isSelected{
          get{
              if(this.isSelected==null)
                this.isSelected = false;
            else
                this.isSelected = true;
              return isSelected;
          }
          set;
          }
      public Contact con{get;set;}
       
         wrapper(contact con){
           //isSelected = false;
            this.con = con;
        }
    }
}

<apex:page controller="t1" >
<apex:form >
<apex:pageBlock id="table">
<apex:commandButton action="{!getSelectedAllContacts}" value="Select All" reRender="table"/>
<apex:pageBlockTable value="{!WrapperContacts}" var="c">
<apex:column >
<apex:inputCheckbox value="{!c.isSelected}">
<apex:actionSupport event="onclick" action="{!getSelectedListContacts}" reRender="table"/>
</apex:inputCheckbox>
</apex:column>
<apex:column value="{!c.con.name}"/>
<apex:column value="{!c.con.title}"/>
</apex:pageBlockTable>
    <!-- To return to first page of records-->
           <apex:commandButton action="{!stdSetController.first}" value="<<" title="First Page" disabled="{!!stdSetController.HasPrevious}" reRender="table,button"/>
           <!-- To return to Previous page of records-->
           <apex:commandButton action="{!stdSetController.previous}" value="Previous" disabled="{!!stdSetController.HasPrevious}" reRender="table,button"/>
           <!-- To return to next page of records-->
           <apex:commandButton action="{!stdSetController.next}" value="Next >" disabled = "{!!stdSetController.HasNext}" reRender="table,button"/>
           <!-- To return to last page of records-->
            <apex:commandButton action="{!stdSetController.last}" value=">>" title="Last Page" disabled="{!!stdSetController.HasNext}" reRender="table,button"/>
</apex:pageBlock>
</apex:form>
</apex:page>

<apex:pageBlockSection id="FolderName" collapsible="true" title="Folder">
				<apex:repeat value="{!foMapNames}" var="fokey">
					<apex:commandLink value="{!foMapNames[fokey]}" action="{!folderIn}" reRender="none">
						<apex:param value="{!fokey}" assignTo="{!foId}"/>
					</apex:commandLink>
					<br/>
				</apex:repeat>
			</apex:pageBlockSection>

global class ContactBatch implements Database.Batchable<sObject>{
}

global class ContactBatch implements Batchable{
}

global class BatchNSchedulable implements Database.Batchable<sObject>{
	global list<contact> con=new list<contact>();
	String query = 'SELECT id,name,status__c FROM contact WHERE CreatedDate= Yesterday';
	global Database.QueryLocator start(Database.BatchableContext bc){
		System.debug('In the start');
		 return (Database.getQueryLocator(query));
	}
	global void execute(Database.BatchableContext bc,list<sObject> li){
		System.debug('In the execute');
		con = (list<contact>)li;
		System.debug(con.size());	
		for(contact ct:con){
			ct.put('status__c','None');
		}
		System.debug('con in execute is '+con);
	}
	global void finish(Database.BatchableContext bc){
		System.debug('con is '+con);
		update con;
		System.debug('In the finish');
	}

}

id i = 0037F00000M6MCHQA3;
String fieldNames='name,id';
String objName = 'contact';
String queryStr = 'SELECT ' + fieldNames + ' FROM ' + objName + ' WHERE id IN :(\'i\')';
System.debug(queryStr);

Schema.sObjectType.Account.fields.getmap()

<apex:component controller ="PaginationForComponent">
    <apex:attribute name= "objectName" description = "The object's name" type = "String" required = "true" assignTo="{!objName}"/>
    <apex:attribute name= "fieldName" description = "Fields to be displayed" type = "String" required ="true" assignTo="{!fieldNames}"/>
<apex:outputLink value="{!URLFOR($Action."{!objName}".Edit,contacts.con.id)}"> 
                        Edit |
                    </apex:outputlink>
                    <apex:outputLink value="{!URLFOR($Action."{!objName}".Delete,contacts.con.id)}"> 
                        Del |
                    </apex:outputlink>

public class PaginationForComponent {
public String objName{get;set;}
	public String fieldNames{get;set;}
}

String objName = 'Contact';
string alphaSearchConct = 'A';
String fieldNames = 'name,id';
list<sObject> ct = Database.query('SELECT '+ fieldNames +'FROM '+ objName +'WHERE lastname Like:'+alphaSearchConct +'%');

public class ContactListViewController {
    public ContactlistViewController(){
        system.debug('constructor first called');
        RecordsPerPageslist=10;
        allContactList = new list<wrapper>();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
        System.debug('constructor called');
    }
    Map<id,Boolean> m = new Map<id,boolean>();  	 // To store boolean values of checkboxes corrosponding to every contact id
    list<contact> con = [SELECT Name,id,Account.name,Title,Phone,Email FROM Contact];
    public list<wrapper> allContactList;			//Wrapper class object
    
    public list<wrapper> getWrapperContacts(){  	//List of wrapper class to display in table
        return allContactList;
    }
    
    public void getSelectedListContacts(){  		// Select contacts and save them in a map
        for(wrapper wc:allContactList){
            m.put(wc.con.id,wc.isSelected);
        }
        
        System.debug('getSelectedListContacts = '+m);
        
    }
    public void getSelectedAllContacts(){			//To select all contacts in a page
        for(wrapper wc:allContactList){
            m.put(wc.con.id,wc.isSelected=true);
        }
    }
    public void next(){
        System.debug('next');
		allContactList.clear();        
        this.stdSetController.next();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
        }
    }
    public void previous(){
		allContactList.clear();        
        this.stdSetController.previous();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public void last(){
        allContactList.clear();        
        this.stdSetController.last();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public void first(){
        allContactList.clear();        
        this.stdSetController.first();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
    }
    }
    public boolean getHasNext(){
        return stdSetController.getHasNext();
    }
    public boolean getHasPrevious(){
        return stdSetController.getHasPrevious();
    }
    public list<String> alphabet{
        get{															//To display a list of alphabets on vf page 
            alphabet = new list<string>{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','Others','All'};
       		return alphabet;	 
                }
        set;
    }
    public String alphaSearchConct{get;set;}							// To get commandlink parameter for alphabet selected
    public Pagereference getalphaSearch(){								//To update contact list as per the alphabet selected by the user
        allContactList.clear();
        if (alphaSearchConct=='All'){
            con = [SELECT name,Account.name,Title,Phone,Email FROM contact];
        }
        else{
            	con = [SELECT name,Account.name,Title,Phone,Email FROM contact WHERE lastName Like:alphaSearchConct+'%'];
        }
        ApexPages.StandardSetController ssc = new ApexPages.StandardSetController(con);
        stdSetController= ssc;
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
        system.debug('alphaSearchconct called');
        return null;
    }      
    public Integer PageNumber{
        get{                                                            //To get current page number
  		    System.debug('get of pageNumber called '+ PageNumber);
            this.PageNumber=stdSetController.getPageNumber();   
            return this.PageNumber;
        }
        set{  
            System.debug('set of pageNumber called');
           	this.pageNumber=value;         
    }
        }
    
    public PageReference NavigateByText(){
        
        System.debug('getNavigateByText '+ stdSetController.getPageNumber());
        allContactList.clear();
        this.stdSetController.setPageNumber(PageNumber);
            for(contact c:(list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c));
            //System.debug(stdSetController.getRecords());
           for(wrapper wc:allContactList){
            wc.isSelected=m.get(wc.con.id);
               System.debug(wc.isSelected);
               System.debug('pageNumber called');
               
    }
        return null;
    }
    public Integer TotalPages{                                            // Total number of pages as per user selection of Records per page
        get{
              if(stdSetController.getResultSize() <=10)
                   this.TotalPages=1;
              if(Math.Mod(stdSetController.getResultSize() ,stdSetController.getPageSize()) == 0)
                  this.TotalPages =(stdSetController.getResultSize()/stdSetController.getPageSize());
              else
                this.TotalPages = (stdSetController.getResultSize()/stdSetController.getPageSize())+1;
              //System.Debug(this.TotalPages);
                return totalpages;
        }
        set;
    }
    public Integer MaxNumberOfRecords{                                    //Maximum number of records in a query list
        get{
             return stdSetController.getRecords().size();
        }
        set;
    }
    public list<SelectOption> getRecordsPerPageOptionList(){              //To display a drop down list on vf page  
            list<SelectOption>  options = new list<SelectOption>();
            options.add(new selectOption('10','10'));
            options.add(new selectOption('25','25'));
            options.add(new selectOption('50','50'));
            options.add(new selectOption('100','100'));
            options.add(new selectOption('200','200'));
            return options;
    }
    public Integer RecordsPerPageslist{ 
        get;
        set{                                                          //To select number of records per page
            if(value!=null){
                this.RecordsPerPagesList=value;
                System.debug('RecordsPerPageList called');
            }
        }       
    }
    public Pagereference getChangeNumberOfRecordsPerPage(){
        allContactList.clear();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
         for(wrapper wc:allContactList)
            wc.isSelected=m.get(wc.con.id);
        return null;
    } 
    public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
        get{
            if(stdSetController==null){
             	 stdSetController = new ApexPages.StandardSetController(con);
            }
              stdSetController.setPageSize(RecordsPerPageslist);        //Limiting Number of records to be displayed per page 
            	System.debug('stdSetController called '+ stdSetController.getPageNumber());
            return stdSetController;   
        }
        set;
    }
    public class wrapper{
      public boolean isSelected{get;set;}
      public Contact con{get;set;}
       
         wrapper(contact con){
            isSelected = false;
            this.con = con;
        }
    }
}

<apex:page controller="ContactListViewController" sidebar="false">
    <apex:form >
        <!-- For alphabetic search-->
        <div align="right">
            <apex:panelGrid >
                <apex:repeat value="{!alphabet}" var="alph">
                    <apex:commandLink value="{!alph} | " action="{!getalphaSearch}" reRender="table">
                        <apex:param name="a" value="{!alph}" assignTo="{!alphaSearchConct}"/>
                    </apex:commandLink>
                </apex:repeat>
            </apex:panelGrid>
        </div>
        <apex:PageBlock id="table">
            <apex:pageMessages />
            <apex:commandButton action="{!getSelectedAllContacts}" value="Select All" reRender="table"/>
            <apex:PageBlockTable value="{!WrapperContacts}" var="contacts" >
                <!-- To display and select Checkboxes-->
                <apex:column >
                    <apex:facet name="header">
                    	<apex:inputCheckbox value="{!contacts.isSelected}">
                        	<apex:actionSupport event="onclick" action="{!getSelectedAllContacts}" reRender="table"/>
                        </apex:inputCheckbox>	
                        </apex:facet>
                    <apex:inputCheckbox value="{!contacts.isSelected}">
                        <apex:actionSupport event="onclick" action="{!getSelectedListContacts}" reRender="table"/>
                    </apex:inputCheckbox>  
                </apex:column>
                <!-- To Edit and Delete a record -->
                <apex:column headerValue="Action">
                    <apex:outputLink value="{!URLFOR($Action.Contact.Edit,contacts.con.id)}"> 
                        Edit |
                    </apex:outputlink>
                    <apex:outputLink value="{!URLFOR($Action.Contact.Delete,contacts.con.id)}"> 
                        Del |
                    </apex:outputlink>
                </apex:column>
                <apex:column headerValue="Name">
                    <apex:outputLink value="/{!contacts.con.id}">
                        {!contacts.con.name}
                    </apex:outputLink>
                </apex:column>
                <apex:column headerValue="Account Name">
                    <apex:outputLink value="/{!contacts.con.account.id}">
                        {!contacts.con.account.name}
                    </apex:outputLink>
                </apex:column>
                <apex:column value="{!contacts.con.Title}"/>
                <apex:column value="{!contacts.con.Phone}"/>
                <apex:column value="{!contacts.con.email}"/>
                <apex:inlineEditSupport />
            </apex:PageBlockTable>
      		</apex:PageBlock> 
        <!-- below code for pagination -->
        <apex:outputPanel id="button"> 
        <div align = "center" >
            <!-- To return to first page of records-->
            <apex:commandButton action="{!first}" value="<<" title="First Page" disabled="{!!HasPrevious}" reRender="table,button"/>
            <!-- To return to Previous page of records-->
            <apex:commandButton action="{!previous}" value="Previous" disabled="{!!HasPrevious}" reRender="table,button"/>
            <!-- To return to next page of records-->
            <apex:commandButton action="{!next}" value="Next >" disabled = "{!!HasNext}" reRender="table,button"/>
            <!-- To return to last page of records-->
            <apex:commandButton action="{!last}" value=">>" title="Last Page" disabled="{!!HasNext}" reRender="table,button"/>
            <!-- InputText to display current page and to navigate to any page number, At righmost side of page-->
            <span style="float:right">
                <apex:outputLabel value="Page ">
                </apex:outputLabel>
                 <!-- To navigate to the page--> 
                <apex:InputText value="{!PageNumber}" maxLength="4" size="1"/>
                <apex:actionSupport event="onchange" action="{!NavigateByText}" reRender="table,button"/>
                <!-- The above action support is not working-->         
                <apex:outputLabel value=" of {!TotalPages}">
                </apex:outputLabel>
            </span>
            <!-- To display a list for number of records to be selected per page-->
            <span style = "float:left">
                <apex:SelectList value="{!RecordsPerPageslist}" size="1" >
                    <apex:selectOptions value="{!RecordsPerPageOptionList}">    
                    </apex:selectOptions>
                    <apex:actionSupport event="onchange" action="{!getChangeNumberOfRecordsPerPage}" reRender="table,button"/>
                </apex:SelectList>
            </span>
        </div>
    </apex:outputPanel>      
    </apex:form>
</apex:page>

public class t1 {
    list<contact> con = [SELECT Name,Account.name,Title,Phone,Email FROM Contact];
    public list<wrapper> allContactList;
    public list<contact> SelectedContact = new list<contact> ();
   
    public list<wrapper> getWrapperContacts(){  
        allContactList = new list<wrapper>();
        for(contact c: (list<contact>)stdSetController.getRecords())
                allContactList.add(new wrapper(c)); 
        return allContactList;
    }

    public void getSelectedListContacts(){
        for(wrapper wc:allContactList){
            System.debug(wc.isSelected+' '+wc.con);
            if(wc.isSelected==true){
                SelectedContact.add(wc.con);
            }
        }
        System.debug(selectedContact);
    }
    public void getSelectedAllContacts(){			//To select all contacts
        for(wrapper wc:allContactList){
            SelectedContact.add(wc.con);
        	//new t1.wrapper().isSelected=true;
        }
    }
     public ApexPages.StandardSetController stdSetController{            //Instantiating a standard set controller
        get{
            if(stdSetController==null){
             	 stdSetController = new ApexPages.StandardSetController(con);
            }
              stdSetController.setPageSize(10);        //Limiting Number of records to be displayed per page 
               return stdSetController;   
        }
        set;
    }
    
    public class wrapper{
      public boolean isSelected{
          get{
              if(this.isSelected==null)
                this.isSelected = false;
            else
                this.isSelected = true;
              return isSelected;
          }
          set;
          }
      public Contact con{get;set;}
       
         wrapper(contact con){
           //isSelected = false;
            this.con = con;
        }
    }
}

<apex:page controller="t1" >
<apex:form >
<apex:pageBlock id="table">
<apex:commandButton action="{!getSelectedAllContacts}" value="Select All" reRender="table"/>
<apex:pageBlockTable value="{!WrapperContacts}" var="c">
<apex:column >
<apex:inputCheckbox value="{!c.isSelected}">
<apex:actionSupport event="onclick" action="{!getSelectedListContacts}" reRender="table"/>
</apex:inputCheckbox>
</apex:column>
<apex:column value="{!c.con.name}"/>
<apex:column value="{!c.con.title}"/>
</apex:pageBlockTable>
    <!-- To return to first page of records-->
           <apex:commandButton action="{!stdSetController.first}" value="<<" title="First Page" disabled="{!!stdSetController.HasPrevious}" reRender="table,button"/>
           <!-- To return to Previous page of records-->
           <apex:commandButton action="{!stdSetController.previous}" value="Previous" disabled="{!!stdSetController.HasPrevious}" reRender="table,button"/>
           <!-- To return to next page of records-->
           <apex:commandButton action="{!stdSetController.next}" value="Next >" disabled = "{!!stdSetController.HasNext}" reRender="table,button"/>
           <!-- To return to last page of records-->
            <apex:commandButton action="{!stdSetController.last}" value=">>" title="Last Page" disabled="{!!stdSetController.HasNext}" reRender="table,button"/>
</apex:pageBlock>
</apex:form>
</apex:page>

trigger ClosedOpportunityTrigger on Opportunity (after insert, after update) {

    List<Task> taskList = new List<Task>();
    
    for (Opportunity opp : [SELECT Id, StageName FROM Opportunity WHERE StageName = 'Closed Won' AND Id IN :Trigger.new]){
                    
            taskList.add(new Task(Subject = 'Follow Up Test Task',
                                  WhatId = opp.Id));
       
    }

    if(taskList.size()>0){
        
        insert taskList;
        
    }
    
}