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>