suddeb

public class AccountTriggerHandler {
    //After Insert Handler
    public class AccountAfterInsertHandler implements MyTriggers.Handler{
        public void handle(){
            System.Debug(LoggingLevel.INFO,'Inside AccountAfterInsertHandler');
        }
    }
    
    //Before Insert Handler
    public class AccountBeforeInsertHandler implements MyTriggers.Handler{

suddeb

trigger AccountTrigger on Account (before insert,after insert) {
	new MyTriggers()
        .attach(MyTriggers.Evt.afterInsert, new AccountTriggerHandler.AccountAfterInsertHandler())
        .attach(MyTriggers.Evt.beforeInsert, new AccountTriggerHandler.AccountBeforeInsertHandler())
        .attach(MyTriggers.Evt.beforeUpdate, new AccountTriggerHandler.AccountBeforeUpdateHandler())
        .run();
}

suddeb

public class AccountTriggerHandler {
    //After Insert Handler
    public class AccountAfterInsertHandler implements MyTriggers.Handler{
        public void handle(){
            System.Debug(LoggingLevel.INFO,'Inside AccountAfterInsertHandler');
        }
    }
    
    //Before Insert Handler
    public class AccountBeforeInsertHandler implements MyTriggers.Handler{

suddeb

public class MyTriggers {
	/* Enum representing all the contexts available */
    public enum Evt {
        afterDelete, afterInsert,afterUndelete,afterUpdate,beforeDelete,beforeInsert,beforeUpdate
    }
    
    public interface Handler{
        void handle();
    }
    

suddeb

public class SecondPageController {
    public String firstName {get;set;}
    
    //Constructor
    public SecondPageController(){
        firstName = System.currentPageReference().getParameters().get('firstName');
    }
}

suddeb

<apex:page controller="SecondPageController">
    Hello {!firstName}
</apex:page>

suddeb

<apex:page >
    <apex:outputLink value="/apex/SecondPage">Click Here -> Second Page
    	<apex:param name="firstName" value="Sudipta"/>
    </apex:outputLink>
</apex:page>

suddeb

<apex:page >
  <br/>
  <apex:pageBlock title="Account Name">
      <apex:pageBlockSection >
          <apex:outputText value="{!$CurrentPage.parameters.accountName}"></apex:outputText>
      </apex:pageBlockSection>
  </apex:pageBlock>
</apex:page>
            

suddeb

public void getMySObjectType(){
	Task MyTask = [Select Id, WhatId from Task where WhatId <> null limit 1];
	String ObjName = MyTask.WhatId.getSObjectType().getDescribe().getName();
	System.Debug('Object Name: ' + ObjName);
}

suddeb

public void getAllSObjects(){
	map<String, Schema.SObjectType> GlobalSObjectMap = Schema.getGlobalDescribe(); 
	for (Schema.SObjectType Obj : GlobalSObjectMap.values()) {
	    Schema.DescribeSObjectResult ObjDesc = Obj.getDescribe();
	    system.debug('Object Name: ' + ObjDesc.getName());
	}
}