Wednesday, 14 November 2012

Virtual Machine

VM ( Virtual Machine)

Dalvik Virtual Machine(DVM)Virtual Machine(VM):- 

VM is an  software implementation of a machine or computer which is used to execute our program like on a physical machine. VM is a set of instructions which will be followed to execute our program. On the basis of use, we have two types of Virtual Machine:-

  1. System Virtual Machine
  2. Process Virtual Machine
System VM are used to simulate complete working of an operating system or hardware.
     Virtual PC, VMWare, etc.

Process VM are used to support an operating system in the execution of an application.

      JVM, CLR(Common Language Runtime used in Dot Net), DVM, etc.

Process VM To Be Continued.........

Monday, 12 November 2012

Android Vs. J2ME

Android Vs. J2ME(Java 2 Micro Edition) 


In Conventional model  of mobile application or say J2ME, we have two major problems:-

  1. Third Party Apps were treated as second class citizen i.e. all the system resources were not available to them and in case of processor/memory request, they were killed first.
  2. To develop an app in a native technology native API's and hardware specification must be learned by the developer which were all available to them at large. To develop an application which has complete access to resources, the  application development require native libraries which are propriated.

Android vs. J2ME using FLOW Diagram 

Android vs. J2ME
Click on the pic to view the complete diagram

Thursday, 1 November 2012

Android Architecture

Architecture of Android

Native App                   3rd Party App             Developer App

Application Framework
(Set of API's written in java to provide productive app developement)

↕                                                                     ↕

                            Native Library                                           Dalvik Virtual Machine 

↕                                                                    ↕

 Linux Kernel
Device Drivers          Power Mgt.          Memory Mgt.           Process Mgt.