Saturday, June 9, 2012

Building Your Application for Release using Eclipse ADT

After you finish configuring your application you can build it into a release-ready .apk fle that is signed and optimized. The JDK includes the tools for signing the .apk file (Keytool and Jarsigner); the Android SDK includes the tools for compiling and optimizing the .apk file. If you are using Eclipse with the ADT plugin or you are using the Ant build script from the command line, you can automate the entire build process.

In preparation for signing your application, you must first ensure that you have a suitable private key with which to sign. Following Keytool command generates a private key:
$ keytool -genkey -v -keystore my-release-key.keystore
-alias alias_name -keyalg RSA -keysize 2048 -validity 10000

Running the example command above, Keytool prompts you to provide passwords for the keystore and key, and to provide the Distinguished Name fields for your key. It then generates the keystore as a file called my-release-key.keystore. The keystore and key are protected by the passwords you entered. The keystore contains a single key, valid for 10000 days. The alias is a name that you — will use later, to refer to this keystore when signing your application.

The Export Wizard performs all the interaction with the Keytool and Jarsigner for you, which allows you to sign the package using a GUI instead of performing the manual procedures to compile, sign, and align, as discussed above. Once the wizard has compiled and signed your package, it will also perfom package alignment with zipalign. Because the Export Wizard uses both Keytool and Jarsigner, you should ensure that they are accessible on your computer.

To create a signed and aligned APK in Eclipse:
  1. Select the project in the Package Explorer and select File > Export.
  2. Open the Android folder, select Export Android Application, and click Next.The Export Android Application wizard now starts, which will guide you through the process of signing your application, including steps for selecting the private key with which to sign the APK (or creating a new keystore and private key).
  3. Complete the Export Wizard and your application will be compiled, signed, aligned, and ready for distribution.