分页插件查询

springmvc-servlet配置：

<bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <!--<property name="typeAliases" value="cn.kgc.util.PageUtil"/>-->
    <property name="typeAliasesPackage" value="cn.kgc.vo;cn.kgc.util"/>
    <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    <!--分页插件版本使用4的版本-->
    <property name="plugins" >
        <array>
            <bean class="com.github.pagehelper.PageHelper">
                <property name="properties">
                    <value>dialect=mysql</value>
                </property>

            </bean>
        </array>
    </property>

</bean>

分页查询，控制层

package cn.kgc.controller;

import cn.kgc.service.EmpService;
import cn.kgc.vo.Emp;
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import java.util.List;
import java.util.Map;

@Controller
@RequestMapping("/emp")
public class EmpController {
    @Autowired
    private EmpService empService;
    @RequestMapping("/page.do")
    public String showPage(Model model, @RequestParam(value = "pageno",
                            required = false,defaultValue = "1")Integer pageno,
                           @RequestParam(value = "deptno",required = false,
                                   defaultValue = "-1")Integer deptno) {
        //设置分页格式，仅对下面第一个集合有效
      Page page=  PageHelper.startPage(pageno, 3);
      //排序方式
        PageHelper.orderBy("empno desc");
        //查询信息，受分页格式影响
        List<Map<String, Object>> emplist = empService.showPage(new Emp(deptno));
        model.addAttribute("emplist", emplist);
        //page信息放入PageInfo，否则前台无法接受
        PageInfo pageinfo = new PageInfo(emplist);
       
        System.out.println(emplist);
        System.out.println(pageinfo);
        model.addAttribute("deptno",deptno);
        model.addAttribute("pageinfo", pageinfo);
        return "/main.jsp";
    }
}

分页，映射xml文件的SQL语句

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="cn.kgc.mapper.EmpMapper">


    <!--各种查询-->
    <select id="selectEmp" parameterType="Emp" resultType="map">
        select d.dname,d.loc,e.* from emp e,dept d where e.deptno=d.deptno
        <if test="empno!=null">
            and e.empno=#{empno}
        </if>
        <if test="deptno!=null and deptno!=-1">
            and d.deptno=#{deptno}
        </if>
    </select>
</mapper>

basedao接口

package cn.kgc.mapper;

import cn.kgc.vo.Emp;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Update;

import java.util.List;
import java.util.Map;

/**
 * Created by Administrator on 2019/6/26.
 */
public interface EmpMapper {

    //查询（查询所有，根据empno查询，根据detpno查询）,mapper.xml
    List<Map<String,Object>> selectEmp(Emp emp);

}

service实现类：

package cn.kgc.service;

import cn.kgc.mapper.EmpMapper;
import cn.kgc.vo.Emp;
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
@Service
@Transactional
public class EmpServiceImpl implements EmpService {
    @Autowired
    private EmpMapper empMapper;


    @Override
    public List<Map<String, Object>> showPage(Emp emp) {
        return empMapper.selectEmp(emp);
    }
}

结果集