HASH KEY - Сharacter length

Hi everyone, I need to compress the values in a field to fit them into a CSV file. In short, I have a field with values longer than 30 characters, so I need to find a way to compress them, possibly using a hash key, without reducing the number of fields. The values in the field vary—some are shorter than 30 characters, some are exactly 30 characters, and some exceed 30 characters. How can I do this in KNIME? Is there a way to write Java code using the Java Snippet node or other methods?