如何使用PageHelper插件进行分页？

<dependency>
       <groupId>com.github.pagehelper</groupId>
       <artifactId>pagehelper</artifactId>
       <version>5.1.2</version>
</dependency>

<plugins>
　　<plugin interceptor="com.github.pagehelper.PageInterceptor">
　　　　　　<property name="helperDialect" value="oracle"/>
       　　<property name="reasonable" value="true"/>
　　</plugin>
</plugins>    

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="plugins">
            <array>
                <bean class="com.github.pagehelper.PageInterceptor">
                    <property name="properties">
                        <props>
                            <!--分页插件会自动检测当前的数据库链接，自动选择合适的分页方式-->
                            <prop key="helperDialect">oracle</prop>
                            <!--当该参数设置为 true 时， pageNum<=0 时会查询第一页，
                                pageNum>pages （超过总数时），会查询最后一页。-->
                            <prop key="reasonable">true</prop>
                        </props>
                    </property>
                </bean>
            </array>
        </property>
 </bean>

@Override
public List<Orders> findAll(int pageNum,int pageSize) {
        PageHelper.startPage(pageNum,pageSize);
        return ordersDao.findAll();
 }

@Controller
@RequestMapping("/orders")
public class OrdersController {

    @Autowired
    private OrdersService ordersService;

    @RequestMapping("/findAll")
    public ModelAndView findAll(@RequestParam(name = "pageNum",required = true,defaultValue = "1") int pageNum,@RequestParam(name = "pageSize",required = true,defaultValue = "5")int pageSize){
        ModelAndView modelAndView = new ModelAndView();
        List<Orders> ordersList = ordersService.findAll(pageNum,pageSize);
        PageInfo pageInfo = new PageInfo(ordersList);
        modelAndView.addObject("pageInfo",pageInfo);
        modelAndView.setViewName("orders-list");
        return modelAndView;
    }
}

<!--数据展示-->
<table id="dataList" class="table table-bordered table-striped table-hover dataTable">
    <thead>
    <tr>
        <th class="" style="padding-right: 0px;">
            <input id="selall" type="checkbox" class="icheckbox_square-blue">
        </th>
        <th class="sorting_asc">ID</th>
        <th class="sorting_desc">订单编号</th>
        <th class="sorting_asc sorting_asc_disabled">产品名称</th>
        <th class="sorting_desc sorting_desc_disabled">金额</th>
        <th class="sorting">下单时间</th>
        <th class="text-center sorting">订单状态</th>
        <th class="text-center">操作</th>
    </tr>
    </thead>
    <tbody>
        <c:forEach items="${pageInfo.list}" var="orders">
            <tr>
                <td><input name="ids" type="checkbox"></td>
                <td>${orders.id }</td>
                <td>${orders.orderNum }</td>
                <td>${orders.product.productName }</td>
                <td>${orders.product.productPrice }</td>
                <td>${orders.orderTimeStr }</td>
                <td class="text-center">${orders.orderStatusStr }</td>
                <td class="text-center">
                    <button type="button" class="btn bg-olive btn-xs">订单</button>
                    <button type="button" class="btn bg-olive btn-xs" onclick="location.href=‘${pageContext.request.contextPath}/orders/findById.do?id=${orders.id}‘">
                        详情
                    </button>
                    <button type="button" class="btn bg-olive btn-xs">编辑</button>
                </td>
            </tr>
        </c:forEach>
    </tbody>
</table>

<!--分页条-->
<div class="box-tools pull-right">
    <ul class="pagination">
        <li>
            <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=1&pageSize=${pageInfo.pageSize}" aria-label="Previous">首页</a>
        </li>
        <li>
            <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=${pageInfo.pageNum-1}&pageSize=${pageInfo.pageSize}">上一页</a>
        </li>
        <c:forEach begin="1" end="${pageInfo.pages}" var="pageNum">
            <c:if test="${pageNum==pageInfo.pageNum}">
                <li class="active">
                    <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=${pageNum}&pageSize=${pageInfo.pageSize}">${pageNum}</a>
                </li>
            </c:if>
            <c:if test="${pageNum!=pageInfo.pageNum}">
                <li>
                    <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=${pageNum}&pageSize=${pageInfo.pageSize}">${pageNum}</a>
                </li>
            </c:if>
        </c:forEach>
        <li>
            <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=${pageInfo.pageNum+1}&pageSize=${pageInfo.pageSize}">下一页</a>
        </li>
        <li>
            <a href="${pageContext.request.contextPath}/orders/findAll?pageNum=${pageInfo.pages}&pageSize=${pageInfo.pageSize}" aria-label="Next">尾页</a>
        </li>
    </ul>
</div>