/** * Checks if the entries tree exists and if this file hasn't been modified since the tree was last created. * If any of those 2 conditions isn't met, the entries tree is (re)created. * * @throws IOException if an error occurred while creating the tree * @throws UnsupportedFileOperationException if {@link FileOperation#READ_FILE} operations are not supported by the * underlying file protocol. */ protected void checkEntriesTree() throws IOException, UnsupportedFileOperationException { if(this.entryTreeRoot==null || getDate()!=this.entryTreeDate) createEntriesTree(); }