Building Android Apps : Submitting Your App to the Android Market - Preparing a Release Version of Your App

You need to do a few things to get the app ready for distribution:

• Remove any debugging or logging code

• Version the app

• Compile the app

• Sign the compiled app with a private key

1. Removing Debug Code

There’s no reason to have debugging or logging code slowing down your app while it’s running on a user’s phone. If you have added any such code to your HTML, CSS, or JavaScript files, now’s the time to take it out.

You should also open up the AndroidManifest.xml file in the KiloGap folder, search for “debuggable” and set it to false. When you’re done, it should look something like this:

...
<application 
    android:icon="@drawable/icon" 
    android:label="@string/app_name"
	android:debuggable="false">
...

---

Note:

While you have the manifest file open, you might as well check to make sure android:icon and android:label are specified as shown in the previous listing. PhoneGap normally takes care of this for you, but I think it’s worth double checking, because you won’t be able to upload your app if these values are not set.

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2. Versioning Your App

Near the top of your AndroidManifest.xml file, you should see values set for the version name and version code for your app:

...
<manifest 
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.jonathanstark.kilo" 
    android:versionName="1.0.0"
    android:versionCode="1">
...

Because this is probably your first app, these values are fine as is. Once you’ve published your app and later want to release an update, you’ll update these values appropriately. The Android system doesn’t check or enforce this version information, but it’s a critical piece of data for your long term app strategy.

The version name is the value that will be shown to the user. It’s a string, so you can put whatever you want here, but the common practice is to use a <major>.<minor>.<point> format (such as 1.0.0).

The version code is expected to be a positive integer value. It need not correspond to the version name in any way. In fact, it probably won’t—you should just increment it by 1 every time you release an update, regardless of whether the release is a major upgrade or a minor bug fix.

3. Signing Your App

Android requires that all apps be digitally signed by the developer. The process for doing so is easy, but a little cryptic:

1. Launch the Terminal application and navigate into the KiloGap directory:

   cd ~/Desktop/KiloGap

   
   

2. Compile the app in release mode:

   ant release

   
   

   You’ll see a page or so of output scroll by, ending with BUILD SUCCESSFUL. An unsigned binary named Kilo-unsigned.apk will now be sitting in the ~/Desktop/KiloGap/bin/ directory (Figure 1).

   Figure 1. The ant release command creates an unsigned binary named Kilo-unsigned.apk in the ~/Desktop/KiloGap/bin/ directory

   

3. Create a private key:

   keytool -genkey -v -keystore keystore -alias alias -keyalg RSA -validity days
   
   					  

   This command is interactive and will ask you a bunch of questions. Mine looks like this:

   
   

   JSC-MBP:KiloGap jstark$ keytool -genkey -v -keystore myAndroidKey.keystore \
                           -alias myAndroidKeyAlias -keyalg RSA -validity 10000
   Enter keystore password:  
   Re-enter new password: 
   What is your first and last name?
     [Unknown]:  Jonathan Stark
   What is the name of your organizational unit?
     [Unknown]:  
   What is the name of your organization?
     [Unknown]:  Jonathan Stark Consulting
   What is the name of your City or Locality?
     [Unknown]:  Providence
   What is the name of your State or Province?
     [Unknown]:  RI
   What is the two-letter country code for this unit?
     [Unknown]:  US
   Is CN=Jonathan Stark, OU=Unknown, O=Jonathan Stark Consulting, L=Providence,
   ST=RI, C=US correct?
     [no]:  yes
   
   Generating 1,024 bit RSA key pair and self-signed certificate (SHA1withRSA) with
   a validity of 10,000 days for: CN=Jonathan Stark, OU=Unknown, O=Jonathan Stark 
   Consulting, L=Providence, ST=RI, C=US
   Enter key password for <myAndroidKeyAlias>
   	(RETURN if same as keystore password):  
   [Storing myAndroidKey.keystore]
   
   					  

   When the process completes, you should see myAndroidKey.keystore created in the ~/Desktop/KiloGap directory (Figure 2). If you’d like to use this keystore for other apps in the future, you might want to move the keystore file to a more central location.

   Figure 2. The keytool command will generate a keystore file named myAndroidKey.keystore in the KiloGap directory

   

   ---

   Warning:

   Do not lose this password. If you forget your keystore password, you won’t be able to update your app once it’s published.

   ---

4. Sign your app with the key you just created:

   jarsigner -verbose -keystore myAndroidKey.keystore 
       ./bin/Kilo-unsigned.apk myAndroidKeyAlias

   
   

   When you run this command, you’ll be asked for your keystore password.

5. Align the .apk file:

   zipalign -v 4 ./bin/Kilo-unsigned.apk ./bin/Kilo.apk

   
   

   You’ll see a page or so of output scroll by, ending with “Verification successful.” A signed binary named Kilo.apk will now be sitting in the ~/Desktop/KiloGap/bin/ directory (Figure 3). This .apk file is your completed app!

   Figure 3. Once you run the jarsigner and zipalign commands, your final app will be generated in the ~/Desktop/KiloGap/bin/ directory