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Showing posts with the label J2ME

MIDlet Signing

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J2ME Security Architecture is driven from Java Sandbox Architecture . J2ME represents two level of securities:- Low Level KVM Security Application Level Security Low Level KVM Security is divided into two steps: Pre-verification performs certain checks on the Java bytecodes using preverify tool, if first level of verification is passed, then preverifier add special stack map attributes into class files to facilitate runtime in-device verification. Note that preverified class files with the special attribute are approximately 5% larger than the original files. In-device verification is performed on real device by KVM. It refers to the additional information attached to the pre-verified files & verify whether the class file is structurally or conceptually correct according to J2ME specifications. As you know small devices are memory constraints, so split verifier improves verification process by generating annotations at compile time and then using this informat...

How to make a call in J2ME?

Hi Readers, Today while working on my blog, I came to know that someone of you are searching for article on "How to make a call in J2ME?". So this article is especially for that user. In this article, I describe you about how to use your phone book & make a call on that number, also you can directly enter any international format number and make a call. So let's start:- Here I'll show you two things - 1) Fetch contacts from your device phonebook, & 2) Make a Call 1) Fetch Contacts from your device phonebook: We can do this activity in two ways - a) By using JSR 75 API, & b) By using TextField property constraint. First method is bit complex and it require signing of application from device vendor, to avoid security prompt while accessing the device phonebook. So we'll skip this method and directly switch to second option. In this you need to use one of the textfield constraint "PHONEBOOK" to access the whole contact list using J2ME ap...

J2ME Polish - Development Framework

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Hi Readers, I hope that my previous post help you some how. Please let me know if you want some more updates or article on any specific area. Today I am going to discuss about J2ME Polish Framework. What is the requirement for development frameworks? Features of J2ME Polish etc. So let's start:- Why we need development frameworks? To answer this question I am going to share one small example that will help you to have better understanding. We'll create a small app which has login functionality. First I am going to use only Java ME classes without any framework. Let's see:- We have two options two create this app, one is by using High Level APIs and other is Low Level APIs .  High Level APIs have pre-defined classes defined. You need to implement the functionality and you need not to worry about coding any graphics yourself and the application looks like (at least to some degree) native application. However there is limited control of the UI and the UI will look diff...

MVC, Design Patterns, J2ME, Optimization

Dear All, Welcome again.... Today I have some specific things to share with all of you... As you all came to know from the title of this article that we are going to discuss MVC approach in J2ME. Earlier I used modular approach to develop mobile application, but now I am exploring more on MVC approach in J2ME and I came to know it is really helpful to develop the secure and modular application. Some of you are well aware of this approach and mostly used in your projects. But some of you may be yet not used such kind of approach in your projects then this article may help all of you. I'll try my best to make you understand this approach using J2ME. For example suppose we have simple application in which user can login and after login user can access some kind of information. Then first of all we can design our application in such a way that data of one class will not exposed to other classes. Suppose all of UI classes will have access using one single class, I name it UIController y...