Errors occur in the class “JDBCStorageService”. At several places “returnedVersion != version” is used.

returnedVersion and version are of type “Long”. Unfortunately, the comparison behaves differently up to 127L than from 128L:

        Long version = 127L;
        Long returnedVersion = 127L;
        System.out.println(version != returnedVersion); //false
        System.out.println(version.longValue() != returnedVersion.longValue()); //false
        System.out.println(!version.equals(version)); //false

        version = 128L;
        returnedVersion = 128L;
        System.out.println(version != returnedVersion); //TRUE !
        System.out.println(version.longValue() != returnedVersion.longValue()); //false
        System.out.println(!version.equals(returnedVersion)); //false

        version = 129L;
        returnedVersion = 129L;
        System.out.println(version != returnedVersion); //TRUE !
        System.out.println(version.longValue() != returnedVersion.longValue()); //false
        System.out.println(!version.equals(returnedVersion)); //false

I would fix the errors with the longValue() addition.

The class also contains the “verion” type twice.

In "log.trace("Considering Version '{}', Expires '{}', Value '{}'", returnedVersion, returnedValue, returnedExpires);" returnedValue and returnedExpires are swapped.