Android Interview Questions and Answers Set 9

81.How can two Android applications share same Linux user ID and share same VM?

The applications must sign with the same certificate in order to share same Linux user ID and share same VM.

82.Can you deploy executable JARs on Android? Which packaging is supported by Android?

No, Android platform does not support JAR deployments. Applications are packed into Android Package (.apk) using Android Asset Packaging Tool (AAPT) and then deployed onto Android platform. Google provides Android Development Tools for Eclipse that can be used to generate Android Package.

83.What is the difference between TRUNCATE and DELETE commands?

Both will result in deleting all the rows in the table .TRUNCATE call cannot be rolled back as it is a DDL command and all memory space for that table is released back to the server. TRUNCATE is much faster.Whereas DELETE call is an DML command and can be rolled back.

84.What is a candidate key?

A table may have more than one combination of columns that could uniquely identify the rows in a table; each combination is a candidate key

85.What is an URIs?

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.
86.What is an Intent Receiver?

An application class that listens for messages broadcast by calling Context.broadcastIntent

87.What is SQLite? How does it differ from client-server database management systems?

SQLite is the open-source relational database of choice for Android applications. The SQLite engine is serverless, transactional, and self-contained. Instead of the typical client-server relationship of most database management systems, the SQLite engine is integrally linked with the application. The library can also be called dynamically, and makes use of simple function calls that reduce latency in database access.

88.Tell us something about nine-patch image.

– The Nine-patch in the image name refers to the way the image can be resized: 4 corners that are unscaled, 4 edges that are scaled in 1 axis, and the middle one that can be scaled into both axes.

– A Nine-patch image allows resizing that can be used as background or other image size requirements for the target device.

89.What is the role of compatibility that is used in Android?

– The compatibility is defined in terms of android compatible devices that run any application. This application is written by third party developers using the Android platform that comes in the form of SDK and NDK.

– There are many filters that are used to separate devices that are there to participate in the compatibility mode for the Android applications. The devices that are compatible require the android to approve it for their trademark. The devices that are not passes the compatibility are just given in the Android source code and can use the android trademark.

– The compatibility is a way through which the user can participate in the Android application platform. The source code is free to use and it can be used by anyone.

90.How long does compatibility take?

The process is automated. The Compatibility Test Suite generates a report that can be provided to Google to verify compatibility. Eventually we intend to provide self-service tools to upload these reports to a public database.