We have added the edu.rice.cs.mint.runtime.MintSerializer class to it that can write code object, including CSP data, to a jar file (or whatever stream you like), and then restore it again. Here is a very simple example:
c = <|123|>;
File f = new File(dir, "IntegerCode1.jar");
MintSerializer.save(c, "IntegerCode1", f);
Integer s = MintSerializer.load(f);
The version of DrJava with Mint is based on the current trunk (and not on updated stable release of DrJava that was made available this week).