public int getPageFirstItem() {
        int cPage = this.getCurrentPage().intValue();

        if (cPage == 1) {
            return 1;
        }

        cPage--;

        int pgSize = this.getPageSize().intValue();

        return (pgSize * cPage) + 1;
    }
Set total item value

@param tItem The totalItem to set.
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/master/web/common/BaseResult.java