How to write a java application for android

Writing your first app and seeing it running on your phone is only half the fun when it comes to Android. Head over to http: Setting Up Your Development Environment Java developers, especially those using Eclipse, will have an easy transition to the Android development world.

How to write a java application for android

Maybe you have a great idea and you want to build a prototype, maybe you just want to learn to program for Android, maybe it is part of a school or college course, or maybe you are just curious.

Example: A Simple Java Program

Whatever the motivation, building Android apps can be fun and rewarding. In this tutorial we go through the steps needed to build your very first Android app. But before we start, it is worth mentioning some of the other resources we have related to writing Android apps.

Included in the download are the Software Development Kit, with all the Android libraries and bits that you need to develop an app; and the Android emulator, so that you can initially test you app on your PC without needing to install it on a real device. Oracle will not be posting any updates of Java SE 7 to its public download sites and it is suggested that users move to Java 8, however at the moment Android Studio requites Java 7.

This could change in the future.

Start a new project

During the install you will need to configure how much memory to reserve for the Android emulator. The emulator runs Android in a kind of virtual machine, as an Android phone with an Intel processor.

However to run this virtual machine the emulator needs to allocate some memory. The installation program will recommend how much memory to reserve and it is probably best to accept the default.

However, be aware that the combination of Android Studio, Java, and the emulator can be quite memory hungry, and your PC will slow to a crawl unless you have lots of RAM. When you first run Android Studio it will perform some initialization including downloading and installing the latest Android SDK.

This can take several minutes, you will just need to be patient. When everything has been downloaded and whenever you subsequently start Android Studio you will see a menu which allows you to start a new project, open an existing project, import a project, and so on.

If you are an independent developer or a hobbyist, enter your domain name. This can take several minutes especially if it is the first time you have created a project.

how to write a java application for android

The default workspace for the IDE is split into three main parts excluding the toolbars etc. On the upper left is the project tree. So instead we are going to add a few little things, not much, but enough to get you started and give you a taste of Android app development! The project tree The project tree holds all the different files and resources that are needed to build your Android app.

If you are familiar with writing simple programs in Java, C, Python, etc you might think that everything will be contained in just one or possibly two files.

However Android app development is a little more complex, however this initial complexity is actually very useful once you start to write your app in earnest. It is an XML file with information about the app including its name.

One of the most common things you will add to this file is the list of permissions needed by the app. Under that folder you will find MainActivity. This is the entry point into your app and for our example app this is the only Java file that we will need.

There are two ways to edit this file. The advantage of this system is that if a string is used multiple times it can be changed in just once place. It also makes it easier to support multiple languages in the app.

To create this sample app we will need to modify MainActivity.To develop Android applications (or any Java applications, for that matter), you need a development environment to write and build applications.

Eclipse is a very popular development environment (IDE) for Java and the preferred IDE for Android development. There are a number of ways to create apps for Android devices, but the recommended method for most developers is to write native apps using Java and the Android SDK.

Java for Android apps is both similar and quite different from other types of Java applications. The title PhoneAVD in Figure 4 refers to the Android Virtual Device (AVD) in which we'll run our Android app.

Converting a Java Program into an Android App | | InformIT

Android Virtual Devices are explained later in this article. Writing Java Code to Load the Layout File. The controls defined in the activity layout file .

Java android - Webopedia: Online Tech Dictionary for IT Professionals Web Search. Learn Java for Android Development: Introduction to Java. by Shane it can be helpful to think of the Dalvik VM as a bubble in which your Android application runs, allowing you to not have to worry about whether the device is a Motorola Droid, an HTC Evo, or the latest toaster running Android.

Let’s pretend we are developing a Java. Bintu Harwani helps Java programmers understand the basic differences between Java and Android applications and the steps required to convert or re-create a Java program as an Android app.

Converting a Java Program into an Android App. By B.M. Harwani; Sep 25, Now let's create the same application in Android. Assuming that the .

Writing Your First Android App — SitePoint