Android - use ant to create build configurations that change configuration values

Question

What I want is a way to have settings that are dependent on build configuration. To give a specific example, my android application connects to a web service. In development, I want the service url to be pulled in from a configurable value. In Test, I want a different value pulled in. In production, yet another value.

So, in code I have something like this:

public class HttpRequestHelper 
{
    private static String GetServiceUrl(ServiceAction action)
    {
        return serviceUrl + action.toString();
    }
}

By default (when debugging/running through eclipse), I want that url to be http://localhost:1234

In Test I want https://test.mydomain.com

In Production I want https://mydomain.com

I am new to eclipse and ant and it has been a long time since I used java. How do I go about setting this up? What should the build.xml look like? I understand that when I want to build the test/prod versions I will need to use the command line. That's okay. But I don't know how to get this serviceUrl auto-set dependent on the build. I'm not even sure the best place to put this information (a resource, a properties file?). I really want to avoid setting it, building, setting it, building, etc.

Answer 1

As answers mentioned above says, you have to place the URLs in a property file like dev.properties, test.properties, prod.properties etc..

Now only thing that you need to do is making your build intelligent enough to choose a property file depending upon environment.

That can be done by passing a parameter to ANT, something like:

$ ant -file MyBuild.xml -DcurrentEnv=dev (For Development environment)
$ ant -file MyBuild.xml -DcurrentEnv=test (For Test)
$ ant -file MyBuild.xml -DcurrentEnv=prod (For Production)

Inside your build script, this is how you can include your property file:

<target name="jarMe">
    <jar destfile="sample.jar" basedir="src" includes="${currentEnv}.properties"/>
</target>

With this in place, whatever name you supply at the time of build, property file with that name will be picked up.

Answer 2

I would start by placing the urls into a properties file that you can then place onto the classpath. Make a test and a production properties file. Then depending on the build place the correct file onto the classpath and pull the properties at runtime.

Answer 3

You could try to have a following property file in your build.properties file:

service.url=*

And you could have http://localhost:1234 or https://test.mydomain.com in local.properties for your development and integration testing, and it could be set to https://mydomain.com in default.properties.

By do ing this, you have will get different value for service.url in different build environment. You could use that value to generate a config file, and parse it into your code, or set it to env variable, or just put it into a resource file, and Android will read it for you:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="service-url">@@toben_to_be_replaced_during_build_time@@</string>
</resources>

Answer 4

Found a tutorial which goes through all the details of using ant to automate a build system, to create and use build configurations, as well as to build the release project with one command. Here it is: http://www.androidengineer.com/2010/06/using-ant-to-automate-building-android.html

Seems a little long, but it goes through all the steps and details involved.