mybatis的物理分页：mybatis-paginator

github上有一个专门针对mybatis的物理分页开源项目：mybatis-paginator，兼容目前绝大多数主流数据库，十分好用，下面是使用步骤：

环境：struts2 + spring + mybatis

一、pom.xml中添加依赖项

   <dependency>
    <groupId>com.github.miemiedev</groupId>
    <artifactId>mybatis-paginator</artifactId>
    <version>1.2.15</version>
   </dependency>

二、mybatis映射文件中按常规写sql语句

     <select id="getFsuList" resultType="N_CA_FSU">
         Select t.RECID                        recId,
                t.GROSSWEIGHT                  grossWeight,
                t.TOTALGROSSWEIGHT             totalGrossWeight,

                t.GROSSWEIGHTUNITCODE          grossWeightUnitCode,
               ...

           From N_CA_FSU t
          Where ...
     </select>

如果使用mybatis-spring来整合mybatis，sqlSessionFactory参考下面修改（主要是加载分页插件）

     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
         <property name="dataSource" ref="dataSource" />
         <property name="configLocation" value="classpath:mybatis-config.xml"></property>
         <property name="typeAliasesPackage" value="acc.entity"></property>
         <property name="mapperLocations" value="classpath:mybatis/**/*.xml"></property>
         <property name="plugins">
             <list>
                 <bean
                     class="com.github.miemiedev.mybatis.paginator.OffsetLimitInterceptor">
                     <property name="dialectClass"
                         value="com.github.miemiedev.mybatis.paginator.dialect.OracleDialect"></property>
                 </bean>
             </list>
         </property>
     </bean>

三、服务层基类

 package acc.service.support;

 import java.io.Serializable;
 import java.util.List;

 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.mybatis.spring.SqlSessionFactoryBean;
 import org.mybatis.spring.SqlSessionUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;

 import com.github.miemiedev.mybatis.paginator.domain.PageBounds;

 public class BaseServiceImpl implements Serializable {

     private static final long serialVersionUID = 1293567786956029903L;

     protected Logger logger = LoggerFactory.getLogger(this.getClass());

     @Autowired
     protected SqlSessionFactoryBean sqlSessionFactory;

     /**
      * 查询分页数据
      *
      * @param mapperClass
      * @param sqlId
      * @param sqlParameter
      * @param pageIndex
      * @param pageSize
      * @return
      * @throws Exception
      */
     protected List<?> getPageList(Class<?> mapperClass, String sqlId,
             Object sqlParameter, int pageIndex, int pageSize) throws Exception {
         SqlSession session = null;
         try {
             SqlSessionFactory sessionFactory = sqlSessionFactory.getObject();
             session = SqlSessionUtils.getSqlSession(sessionFactory);
             if (pageIndex <= 0) {
                 pageIndex = 1;
             }
             if (pageSize <= 0) {
                 pageSize = 10;
             }
             PageBounds pageBounds = new PageBounds(pageIndex, pageSize);
             return session.selectList(mapperClass.getName() + "." + sqlId,
                     sqlParameter, pageBounds);
         } finally {
             session.close();
         }

     }

 }

四、具体的服务层子类调用

 package acc.service.support;

 ...

 @Service
 public class FsuServiceImpl extends BaseServiceImpl implements FsuService {

     private static final long serialVersionUID = 6560424159072027262L;

     @Autowired
     FsuMapper fsuMapper;

     ...

     @SuppressWarnings("unchecked")
     @Override
     public PageList<N_CA_FSU> getAll(int pageIndex, int pageSize)
             throws Exception {
         return (PageList<N_CA_FSU>) getPageList(FsuMapper.class, "getFsuList",
                 null, pageIndex, pageSize);
     }

     ...

 }

服务层就处理完了，接下来看Action层

五、Action基类

 package acc.action;

 import org.apache.struts2.ServletActionContext;
 import org.apache.struts2.convention.annotation.ParentPackage;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import acc.lms.invoker.utils.StringUtils;

 import com.opensymphony.xwork2.ActionSupport;

 @ParentPackage("default")
 public class BaseController extends ActionSupport {

     protected Logger logger = LoggerFactory.getLogger(this.getClass());

     private static final long serialVersionUID = -8955001188163866079L;

     private int pageSize = 15;

     private int pageIndex = 1;

     private int totalCounts = 0;
     private int totalPages = 0;

     public int getPageSize() {
         return pageSize;
     }

     public void setPageSize(int pageSize) {
         this.pageSize = pageSize;
     }

     public int getPageIndex() {
         String t = ServletActionContext.getRequest().getParameter("pageIndex");
         if (!StringUtils.isEmpty(t)) {
             pageIndex = Integer.parseInt(t);
         }
         return pageIndex;
     }

     public int getTotalCounts() {
         return totalCounts;
     }

     public void setTotalCounts(int totalCounts) {
         this.totalCounts = totalCounts;
     }

     public int getTotalPages() {
         return totalPages;
     }

     public void setTotalPages(int totalPages) {
         this.totalPages = totalPages;
     }

 }

注：约定分页时，url类似  /xxx.action?pageIndex=N

六、具体的Action子类调用

 package acc.action;

 ...

 @Results({ @Result(name = "success", type = "redirectAction", params = {
         "actionName", "fsu" }) })
 public class FsuController extends BaseController implements
         ModelDriven<Object> {

     ...
     @Autowired
     FsuService fsuService;

     ...

     // GET /fsu
     public HttpHeaders index() throws Exception {
         list = fsuService.getAll(getPageIndex(), getPageSize());

         setPageSize(list.getPaginator().getLimit());
         setTotalCounts(list.getPaginator().getTotalCount());
         setTotalPages(list.getPaginator().getTotalPages());

         return new DefaultHttpHeaders("index").disableCaching();
     }

     ...

 }

七、前端页面

 <link href="${pageContext.request.contextPath}/resources/css/simplePagination/simplePagination.css" rel="stylesheet" type="text/css"/>
 <script type="text/javascript" src="${pageContext.request.contextPath}/resources/js/common/jquery-1.7.1.min.js"></script>
 <script type="text/javascript" src="${pageContext.request.contextPath}/resources/js/common/simplePagination/jquery.simplePagination.js"></script>
     <script type="text/javascript">
         var pageIndex = ${pageIndex};
         var pageSize = ${pageSize};
         var totalPages = ${totalPages};
         var totalCounts = ${totalCounts};

         $(document).ready(function() {

             $("#page-box").pagination({
                     items: totalCounts,
                     itemsOnPage: pageSize,
                     currentPage:pageIndex,
                     cssStyle: 'light-theme',
                     prevText:'<',
                     nextText:'>',
                     onPageClick:function(page){
                         gotoPage(page);
                     }
             });
             showPageInfo();

         });

         function gotoPage(page) {
             window.location = "${pageContext.request.contextPath}/fsu?pageIndex=" + page;
         }

         function showPageInfo(){
             $("#page-info").html(pageSize + "条/页，共" + totalCounts + "条，第" + pageIndex + "页，共" + totalPages + "页");
         }
     </script>

 <table class="tableE">
     <thead>
         <tr>
             <th>运单号</th>
             <th>起始站</th>
             ...
         </tr>
     </thead>

     <tbody>
         <s:iterator value="list">
             <tr>
                 <td>${waybillNumber}</td>
                 <td>${origin}</td>
                 ...
             </tr>
         </s:iterator>
     </tbody>
 </table>

 <div id="page-box"></div>

解释：jquery的分页插件，网上一搜索一大堆，我用的是jquery.simplePagination，${pageIndex}、${pageSize}...包括list，这些属性都是后台Action中的model属性

后记：

github上还有另一款mybatis的分页插件：Mybatis-PageHelper 也十分好用，使用说明参考：http://git.oschina.net/free/Mybatis_PageHelper/blob/master/wikis/HowToUse.markdown

使用示例：

     @Test
     public void testPagination() {
         HUserMapper userMapper = context.getBean(HUserMapper.class);
         Map<String, Object> param = new HashMap<>();
         param.put("city", "上海");
         //startPage后紧接的第1个mybatis查询方法被会分页
         PageHelper.startPage(3, 10);//第3页开始,每页10条
         PageInfo<HUser> pageInfo = new PageInfo<>(userMapper.queryByMap(param));
         for (HUser u : pageInfo.getList()) {
             log.info("userId:{}", u.getUserId());
         }
         log.info("pageIndex:{},pageSize:{},pageCount:{},recordCount:{}",
                 pageInfo.getPageNum(), pageInfo.getPageSize(),
                 pageInfo.getPages(), pageInfo.getTotal());

     }

mybatis-config.xml中的配置：

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 <configuration>
     <settings>
         <setting name="logImpl" value="LOG4J2"/>
     </settings>

     <plugins>
         <plugin interceptor="com.github.pagehelper.PageHelper">
             <!--下面的参数详解见http://git.oschina.net/free/Mybatis_PageHelper/blob/master/wikis/HowToUse.markdown-->
             <property name="dialect" value="mysql"/>
             <property name="reasonable" value="true"/>
             <property name="offsetAsPageNum" value="true"/>
             <property name="rowBoundsWithCount" value="true"/>
             <property name="pageSizeZero" value="true"/>
         </plugin>

         <plugin interceptor="tk.mybatis.mapper.mapperhelper.MapperInterceptor">
             <property name="mappers" value="tk.mybatis.mapper.common.Mapper"/>
             <property name="IDENTITY" value="MYSQL"/>
             <property name="notEmpty" value="true"/>
         </plugin>
     </plugins>

 </configuration>