Programmer's Notebook

ReactiveX Asynchronous Programming In Java There is a much detailed blog about ReactiveX of myself, checkout here . Table of Contents What is Asynchronous programming? Ways of Asynchronous programming in java Java Callback functions Java Future Benefit of RxJava 1 What is Asynchronous programming? The asynchronous issue exists, because of the blocking nature of every activity in reality. Every operation consume time, in theory, computers need to take at least one frequency to execute one instruct, it takes time between every oral conversation in the speed of voice at least. That's the blocking nature of this world, and the most valuable resource of all is the time. Some times the computer cannot wait for that longer for the blocking API, like in network communication, it waste of the computer resource so much. The another reason is the event-based scenario. In a network connected chatting app, program listens for every coming data continuously and output

Android Account Manager Table of Contents the begging of an Internet mobile app Account Management Demos 1 the begging of an Internet mobile app The first component that an Internet startup needs to build is its user system. How to expand his users in an easily, convenient and user-friendly way, and how to develop its account system in a scalable method? The account system is the crucial and the most important part of a company, most of the content and service provider companies always develop its account systems followed the oAuth standard. There are third party authentication plugins, like stormpath and Auth0 targeted into those account management field, you can build your web app above that service. For an Android mobile developer, there are already a middle-ware in API level, AccountManager. Take a glance of Account preference in the Setting App, and experience how Gmail, Youtube, and G+ works with multi-shared google accounts and switch between them i

Logical Volume Management Table of Contents What is LVM? Conceptions How to create PV create VG create LV 1 What is LVM? LVM stands for Logical Volume Management, which is one kind of virtual disk partition. In the traditional way, We need to separate a disk into multiple partitions, then format that partition with a filesystem. Once you write the partition table to the disk, rewrite this table will lose all your disk data. But, LVM gave more scalable and dynamic options, we can adjust and re-create partitions without reboot and re-mount process. 2 Conceptions VG:   Volume Groups PV:  Physical Volumes LV:   Logical Volumes Volume Groups is a collection of Logical volumes, and it is created on top of physical volumes, Physical Volumes are physical disk partitions with LVM header. Logical Volumes are the final partitions that we can format with our favorite filesystem. Topology of these concepts: one Volume Group can include more than one Phys