Select the newest release and download it.
Uncompress the file.
Go to portico-portico-x.x.x\codebase folder.
Navigate to the codebase\ directory.
Open the file build.properties and set all the JDK.HOME variables with your Java environment. Save the file.
Now run .\ant.bat (or ./ant if you’re not on windows).
Your portico.jar will be generated.
Thanks to Michael Fraser.
If you want to build only for Java, you can pass java.sandbox or java.release to ant :
> ant java.release