- .apk extension
- The extension for an Android package file, which typically contains all of the files
related to a single Android application. The file itself is a compressed collection
of an AndroidManifest.xml file, application code (.dex files), resource
files, and other files. A project is compiled into a single .apk file.
- .dex extension
- Android programs are compiled into .dex (Dalvik Executable) files, which
are in turn zipped into a single .apk file on the device. .dex files can
be created by automatically translating compiled applications written in
the Java programming language.
- A description of something that an Intent sender wants done. An action is
a string value assigned to an Intent. Action strings can be defined by Android
or by a third-party developer. For example, android.intent.action.VIEW
for a Web URL, or com.example.rumbler.SHAKE_PHONE for a custom application
to vibrate the phone.
- A single screen in an application, with supporting Java code, derived from
the Activity class.
- Android Debug Bridge, a command-line debugging application shipped with the
SDK. It provides tools to browse the device, copy tools on the device, and
forward ports for debugging. See Using adb for more information.
- A collection of one or more activities, services, listeners, and intent receivers.
An application has a single manifest, and is compiled into a single .apk
file on the device.
- Content Provider
- A class built on ContentProvider that handles content
query strings of a specific format to return data in a specific format.
and writing data to a content provider for information on using
- Content URI
- A type of URI. See the URI entry.
- The name of Android's virtual machine. The Dalvik VM is an interpreter-only
virtual machine that executes files in the Dalvik Executable (.dex) format,
a format that is optimized for efficient storage and memory-mappable execution.
The virtual machine is register-based, and it can run classes compiled by
a Java language compiler that have been transformed into its native format
using the included "dx" tool.
The VM runs on top of Posix-compliant operating systems, which it relies
on for underlying functionality (such as threading and low level memory management).
The Dalvik core class library is intended to provide a familiar
development base for those used to programming with Java Standard
Edition, but it is geared specifically to the needs of a small mobile
- Dalvik Debug Monitor Service, a GUI debugging application shipped with the
SDK. It provides screen capture, log dump, and process examination capabilities.
See Using the Dalvik
Debug Monitor Server to learn more about this
- A compiled visual resource that can be used as a background, title, or other
part of the screen. It is compiled into an android.graphics.drawable
- A class (Intent) that contains several fields describing
what a caller would like to do. The caller sends this intent to Android's
intent resolver, which looks through the intent filters of all applications
to find the activity most suited to handle this intent. Intent fields include
the desired action, a category, a data string, the MIME type of the data, a handling
class, and other restrictions.
- Intent Filter
- Activities and intent receivers include one or more filters in their manifest
to describe what kinds of intents or messages they can handle or want to
receive. An intent filter lists a set of requirements, such as data type,
action requested, and URI format, that the Intent or message must fulfill.
For Activities, Android searches for the Activity with the most closely matching
valid match between the Intent and the activity filter. For messages, Android
will forward a message to all receivers with matching intent filters.
- Intent Receiver
- An application class that listens for messages broadcast by calling Context.broadcastIntent().
For example code, see Listening
for and broadcasting global messages.
- Layout resource
- An XML file that describes the layout of an Activity screen.
- An XML file associated with each Application that describes the various activies,
intent filters, services, and other items that it exposes. See AndroidManifest.xml
- Nine-patch / 9-patch / Ninepatch image
- A resizeable bitmap resource that can be used for backgrounds or other images
on the device. See Nine-Patch Stretchable
Image for more information.
- Query String
- A type of URI. See the URI entry.
- A user-supplied XML, bitmap, or other file, entered into an application build
process, which can later be loaded from code. Android can accept resources
of many types; see Resources for a full description.
Application-defined resources should be stored in the
- A class that runs in the background to perform various persistent actions,
such as playing music or monitoring network activity.
- A set of properties (text size, background color, and so on) bundled together
to define various default display settings. Android provides a few standard
themes, listed in R.style (starting with "Theme_").
- Android uses URI strings both for requesting data (e.g., a list of contacts)
and for requesting actions (e.g., opening a Web page in a browser). Both
are valid URI strings, but have different values. All requests for data must
start with the string "content://". Action strings are valid URIs
that can be handled appropriately by applications on the device; for example,
a URI starting with "http://" will be handled by the browser.