Here is a solution that was helpful in my case...
Suppose .jar file sits in "c:empin.jar". In command prompt window cd to ..android-sdkplatform-tools.
To get .apk execute:
dx --dex --output="c:empapp.apk" "c:empin.jar"
To get .dex file execute:
dx --dex --output="c:empdx.dex" "c:empin.jar"
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