Book Image

Android 3.0 Application Development Cookbook

By : Kyle Merrifield Mew
Book Image

Android 3.0 Application Development Cookbook

By: Kyle Merrifield Mew

Overview of this book

<p>Android is a mobile operating system that runs on a staggering number of smartphones and tablets. Android offers developers the ability to build extremely rich and innovative applications written using the Java programming language. Among the number of books that have been published on the topic, what&rsquo;s missing is a thoroughly practical, hands-on book that takes you straight to getting your job done without boring you with too much theory.<br /><br />Android 3.0 Application Development Cookbook will take you straight to the information you need to get your applications up and running. This book is written to provide you with the shortest possible route between an idea and a working application. <br /><br />Work through the book from start to finish to become an Android expert, or use it as a reference book by applying recipes directly to your project.<br /><br />This book covers every aspect of mobile app development, starting with major application components and screen layout and design, before moving on to how to manage sensors such as internal gyroscopes and near field communications. Towards the end, it delves into smartphone multimedia capabilities as well as graphics and animation, web access, and GPS. <br /><br />Whether you are writing your first app or your hundredth, this is a book that you will come back to time and time again, with its many tips and tricks on the rich features of Android 3.</p>
Table of Contents (18 chapters)
Android 3.0 Application Development Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using internal storage for private data


As we saw in Chapter 1, Activities, Android provides a variety of methods for storing user preferences and settings but many applications require a more sophisticated filing system and a convenient way to do this is by using our handset's internal storage.

As one might expect the Java OutputStream object forms the basis for most of these types of operations.

Getting ready

Writing to internal storage is done through our Java activity class, so start up a new Android project in Eclipse and open the main activity pane.

How to do it...

  1. Declare two string fields FSPC and mString to act as our filename and content:

    final static String FSPC = "my_file.txt";
    private final String mString = "a string";
  2. Inside the onCreate() method add the following lines:

    FileOutputStream outStream;
    
    try {
      outStream = openFileOutput(FSPC, Context.MODE_PRIVATE);
      outStream.write(mString.getBytes());
      outStream.close();
    
    } catch (FileNotFoundException e) {
      e.printStackTrace();...