A new variable type should be created that stores a java.lang.String as in a byte array.
Original request: "Is there a particular reason for the TEXT_ field in ACT_RU_VARIABLE being a varchar(255) instead of a clob? If not it would be great if a clob were used instead to facilitate the storage of larger strings."
WORKAROUND: as a temporary workaround, users can just stick the bytes into the process variables:
execution.setVariable("long text", myTextString.getBytes());
new String((byte)execution.getVariable("long text"));