Avoid repeat of completed tasks

[Uri Zeituni <ur...@retalix.com>]

Hello all,
I have a few independent tasks each one creates a jar file and I execute each one by itself. Most of them depend on the same general jar tasks. 
The situation now is that I want to call all of them within an EAR task. I use <antcall> task to do that.
Every task calls the general task that it depends on, so I have a situation where a general task that everyone depends on is called a few times. It seems like a waste of time. 
Here is an example of the output (I highlighted the repeated dependant tasks):

buildTechCore:
     [echo] TechCore compiled successfully
     [echo] TechCore.jar created

buildAppCore:
     [echo] Application core resources copied
    [javac] Compiling 772 source files to C:\SCMBuild\classes\ApplicationCore
   [ejbjar] building ApplicationCore.jar with 796 files
     [echo] ApplicationCore.jar created
     [echo] Core projects created successfully

buildWFEngine:
    [javac] Compiling 78 source files to C:\SCMBuild\classes\Workflow
   [ejbjar] building SCMWorkFlowEngine.jar with 93 files

buildFE:
    [javac] Compiling 159 source files to C:\SCMBuild\classes\Frontend
     [echo] Frontend project compiled successfully
   [ejbjar] building SCMFWFrontEnd.jar with 165 files
     [echo] SCMFronend.jar created

buildWebModule:
     [echo] SCMWeb resources copied
     [echo] SCMWeb classes compiled successfully
     [echo] SCMWeb.war created

buildCommonApp:
    [javac] Compiling 409 source files to C:\SCMBuild\classes\CommonApp
   [ejbjar] building SCMCommonApplication.jar with 422 files

buildGDSN:
    [javac] Compiling 12 source files to C:\SCMBuild\classes\GDSN
   [ejbjar] building GDSN.jar with 31 files

buildTechCore:
     [echo] TechCore compiled successfully
     [echo] TechCore.jar created

buildAppCore:
     [echo] Application core resources copied
    [javac] Compiling 772 source files to C:\SCMBuild\classes\ApplicationCore
   [ejbjar] building ApplicationCore.jar with 796 files
     [echo] ApplicationCore.jar created
     [echo] Core projects created successfully

buildWFEngine:
    [javac] Compiling 78 source files to C:\SCMBuild\classes\Workflow
   [ejbjar] building SCMWorkFlowEngine.jar with 93 files

buildFE:
    [javac] Compiling 159 source files to C:\SCMBuild\classes\Frontend
     [echo] Frontend project compiled successfully
   [ejbjar] building SCMFWFrontEnd.jar with 165 files
     [echo] SCMFronend.jar created

buildWebModule:
     [echo] SCMWeb resources copied
     [echo] SCMWeb classes compiled successfully
     [echo] SCMWeb.war created

buildCommonApp:
    [javac] Compiling 409 source files to C:\SCMBuild\classes\CommonApp
   [ejbjar] building SCMCommonApplication.jar with 422 files

buildOMS:
    [javac] Compiling 224 source files to C:\SCMBuild\classes\OMS
   [ejbjar] building OMS.jar with 229 files

buildTechCore:
     [echo] TechCore compiled successfully
     [echo] TechCore.jar created

buildAppCore:
     [echo] Application core resources copied
    [javac] Compiling 772 source files to C:\SCMBuild\classes\ApplicationCore
   [ejbjar] building ApplicationCore.jar with 796 files
     [echo] ApplicationCore.jar created
     [echo] Core projects created successfully

buildWFEngine:
    [javac] Compiling 78 source files to C:\SCMBuild\classes\Workflow
   [ejbjar] building SCMWorkFlowEngine.jar with 93 files

buildFE:
    [javac] Compiling 159 source files to C:\SCMBuild\classes\Frontend
     [echo] Frontend project compiled successfully
   [ejbjar] building SCMFWFrontEnd.jar with 165 files
     [echo] SCMFronend.jar created

buildWebModule:
     [echo] SCMWeb resources copied
     [echo] SCMWeb classes compiled successfully
     [echo] SCMWeb.war created

buildCommonApp:
    [javac] Compiling 409 source files to C:\SCMBuild\classes\CommonApp
   [ejbjar] building SCMCommonApplication.jar with 422 files

and so on....

How can I avoid this situation, so the general tasks will not repeat themselves but will be executed only once?
Many thanks,
Zeituni