<!-- 分页插件 -->
<plugins>
    <plugin interceptor="com.github.pagehelper.PageHelper">
        <property name="dialect" value="mysql" />
        <property name="pageSizeZero" value="true" />
        <property name="reasonable" value="true" />
    </plugin>
</plugins>

// 分页查询
PageHelper.startPage(pageNum, 10);
List<Demo> demoList= demoService.getDemoList();
PageInfo<Demo> resList = new PageInfo<Demo>(demoList);

// PageInfo.getLastPage()获取最后一页的页码
if (pageNum <= resList.getLastPage()) {
    rm.setCode("200");
    rm.setMsg("分页查询列表成功");
    rm.setResult(resList.getList());
} else {
    rm.setCode("400");
    rm.setMsg("分页查询列表失败");
}