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Android Ant build on a project with two source folders

Posted by: admin June 15, 2020 Leave a comment


I have a project with a linked source folder. This project depends on another (remote service) project, so the aidl files and the classes passed across the remote interface are in a common_src linked folder shared between the two projects. This work just fine with Eclipse builds, (one source file, two projects, changes in one project are reflected in the other, just as it should be).

I’d now like to do an Ant build from the command line. I managed to get another project with a single src directory building across all targets using the example build.xml from the SDK tools. It imports ant_rules_r3.xml automatically and once the source.dir and out.dir are defined in the build.properties it’s all fairly painless.

Turning to the project with the src and common_src folders, I can’t get it to build. Firstly I cut and pasted the compile target and all those it depends upon into the build.xml above the setup task. I added and defined the element common_src to the build.properties and added the last line shown below to the -compile target (copied from ant_rules_r3.xml) into the build xml:

  <src path="${source.absolute.dir}" />
  <src path="${gen.absolute.dir}" />
  <src path="${common_src}" /><!--ADDED-->

which got it further on in the build process – it could find the .java files in common_src but not the .aidl files. No surprise I realised as the aidl is a separate target. I then added

<src path="${common_src}" /> 

to the -aidl target in the build xml, and it failed with:

C:\dev\projects\Eclipse\AndroidWorkspace\MapProject\build.xml:77: aidl doesn't
 support the nested "src" element.

So that’s got me well and truly stuck. Ideally I’d like to modify just the build.properties file to include the common_src and pass it to the ant_rules_r3.xml but I can’t think of a way of doing it. I’d be most grateful if anyone can suggest how it can be done.

How to&Answers:

I had a similar issue, but it seems to have been resolved for me by the following setting in my build.properties file:

source.dir = src;../other_project/src

I used a relative path to link my src to other_project, but you should be able to use an absolute path. If you do, you should probably put it in local.properties instead.

Note: according to the comments in build.properties, if my SDK version < 2.0 I would use this instead:

source-folder = src;../other_project/src


Just in case there’s any interest, I thought I’d answer my own question which is now solved.

1) I defined the common_src in the build.properties

2) Added the line

<src path="${common_src}"

in an overriden compile target in the build.xml above the setup (plus overrode all the targets it depended on by cutting/pasting from the ant_rules_r3.xml)
3) Added a new target ‘aidl2’ the same as ‘aidl’ in build.xml but which had the line

<source path="${common_src}" instead of

<source path="${source.absolute.dir}" .

Made aidl depend on aidl2. Overrode all the targets aidl depended on.

I also added lines like :


to the build.xml which automated the input of passwords. I finally added an install_release target to make an automatic one command build, rease and install process.


I can’t comment because I don’t have enough reputation but it if adding a source folder works with previous answers, it fails later when building jar :

    [javac] Compiling 463 source files to /home/xxx/documents/eclipse/xxx/deploy/xxx/bin/classes
    [javac] Note: Some input files use or override a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: Some input files use unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] Creating empty /home/xxx/documents/eclipse/xxx/deploy/xxx/bin/classes/fr/xxx/android/socialintegration/facebook/package-info.class
     [echo] Creating library output jar file...

/home/xxx/applis/android/android-sdk-linux/tools/ant/build.xml:570: The following error occurred while executing this line:
/home/xxx/applis/android/android-sdk-linux/tools/ant/build.xml:680: The following error occurred while executing this line:
/home/xxx/applis/android/android-sdk-linux/tools/ant/build.xml:744: /home/xxx/documents/eclipse/xxx/deploy/xxx/src;../xxxdata/src does not exist.

The faulty part is in the building of the jar that use source.absolute.dir as a filset which in invalid for ant.

But I don’t have any workaround for now and I don’t understand why others have managed to make it work …
(I’m also using sdk r20)


Add ; separated list of sources to your ant.properties (don’t forget to include default src as well):


Above works fine with Android SDK Tools Revision 20.0.3+ (Project Target: Android 2.2+, API level: 8+).


here is the solution:

update your build.xml for more than one source.dir



At least on later versions of the build tools, the problem is that the value put into this property gets passed into a <property name="source.absolute.dirs" location="source.dirs"/>. The location attribute doesn’t know how to deal with colon / semicolon-separated paths.

The fix is very simple, just use:


etc., as opposed to: