使用Mybatis的插件 PageHelper 分页查询

一、导入需要的JAR

jar下载地址：点击打开链接

jsqlparser-0.9.5.jar   

pagehelper-5.0.0.jar

如果是maven项目 就添加下面依赖

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.0.0</version>
</dependency>

二、在mybatis-config.xml中添加配置

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

reasonable：分页合理化参数，默认值为false。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。默认false 时，直接根据参数进行查询

三、代码部分

3.1 实体类代码

import java.util.Date;

public class Mobile {
    private Integer id;

    private String mobiletype;

    private String mobiledesc;

    private Date ontime;

    private Double price;

    private String picpath;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getMobiletype() {
        return mobiletype;
    }

    public void setMobiletype(String mobiletype) {
        this.mobiletype = mobiletype == null ? null : mobiletype.trim();
    }

    public String getMobiledesc() {
        return mobiledesc;
    }

    public void setMobiledesc(String mobiledesc) {
        this.mobiledesc = mobiledesc == null ? null : mobiledesc.trim();
    }

    public Date getOntime() {
        return ontime;
    }

    public void setOntime(Date ontime) {
        this.ontime = ontime;
    }

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    public String getPicpath() {
        return picpath;
    }

    public void setPicpath(String picpath) {
        this.picpath = picpath == null ? null : picpath.trim();
    }
}

3.2 dao层

  3.21 接口

import com.hpit.domain.Mobile;
import com.hpit.domain.MobileExample;
import java.util.List;
import org.apache.ibatis.annotations.Param;

public interface MobileMapper {
    List<Mobile> selectByMobile(@Param("mobile") Mobile mobile,@Param("mobiletype") String mobiletype);
}

 3.22mapper文件

<?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="com.hpit.dao.MobileMapper">
  <resultMap id="BaseResultMap" type="com.hpit.domain.Mobile">
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="mobiletype" jdbcType="VARCHAR" property="mobiletype" />
    <result column="mobiledesc" jdbcType="VARCHAR" property="mobiledesc" />
    <result column="ontime" jdbcType="TIMESTAMP" property="ontime" />
    <result column="price" jdbcType="DOUBLE" property="price" />
    <result column="picpath" jdbcType="VARCHAR" property="picpath" />
  </resultMap>


<select id="selectByMobile"  resultMap="BaseResultMap">
    select distinct
    id, mobiletype, mobiledesc, ontime, price, picpath
    from mobile
    where 1=1
    <if test="mobiletype !='' and mobiletype !=null" >
    and mobiletype like CONCAT(TP_REPLACE(#{mobiletype}),'%') ESCAPE '/'
    </if>
    order by id
     </select> 
</mapper>

3.3 service层

    3.31 接口

import java.util.List;
import com.hpit.domain.Mobile;
public interface MobileService {
	List<Mobile> selectByMobile(Mobile mobile,String mobiletype);
}

    3.32 接口实现类

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.hpit.dao.MobileMapper;
import com.hpit.domain.Mobile;
import com.hpit.domain.MobileExample;
import com.hpit.service.MobileService;
@Transactional
@Service
public class MobileServiceImpl implements MobileService{
	@Autowired
	private MobileMapper mobileMapper;
	public List<Mobile> selectByMobile(Mobile mobile,String mobiletype) {
		return mobileMapper.selectByMobile(mobile,mobiletype);
	}

}

3.3 controller层

	public String list(@RequestParam(value="pageNum",defaultValue="1")Integer pageNum,String mobiletype,
			Model model){
		Mobile mobile=new Mobile();	
		int pageSize=2;
		PageHelper.startPage(pageNum, pageSize);             //传入pageNum, pageSize
		if (null!=mobiletype && !mobiletype.equals("")){
			mobile.setMobiletype(mobiletype);
		}
		List<Mobile> list=mobileService.selectByMobile(mobile, mobiletype);
		PageInfo<Mobile> pageInfo=new PageInfo<Mobile>(list);   //将查询的集合传给pageInfo
		
		model.addAttribute("pageInfo", pageInfo);
		model.addAttribute("pageNum", pageNum);
		model.addAttribute("mobiletype", mobiletype);

		return "list";
	}

四 JSP部分

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery-1.8.0.min.js"></script>
<script type="text/javascript">
	function do_page(pageNo){
		$("#pageNum").val(pageNo);
		$("#form1").submit();
	}
</script>
</head>
<body>
<div style="width:1000px; text-align:center">
 <h3>手机信息</h3>
</div>
<div style="width:1000px; text-align:center">
<form action="${pageContext.request.contextPath}/mobile/list.html" method="post" id="form1">
<input name="pageNum" type="hidden" id="pageNum" value="1" />
 手机型号
   <label>
   <input type="text" name="mobiletype" />
   </label>
   <label>
   <input name="Search" type="submit" id="Search" value="搜索" />
   </label>
   </form>
</div>
<div style="width:1000px; text-align:center">
 <a href="${pageContext.request.contextPath}/add.jsp">添加</a>
</div>
<table width="1000" border="1">
  <tr>
    <td>编号</td>
    <td>类型</td>
    <td>上架时间</td>
    <td>价格</td>
    <td>图片路径</td>
    <td>图片</td>
    <td>删除</td>
    <td>修改</td>
    <td>详细</td>
    <td>下载</td>
  </tr>
  
  <c:if test="${not empty pageInfo.list}">
<c:forEach items="${pageInfo.list}" var="mobile">
	 <tr>
	    <td>${mobile.id}</td>
	    <td>${mobile.mobiletype}</td>
	    <td><fmt:formatDate value="${mobile.ontime}" pattern="yyyy-MM-dd"/></td>
	    <td>${mobile.price}</td>
	    <td>${mobile.picpath}</td>
	    <td><img alt="" src="${pageContext.request.contextPath}/upload/${mobile.picpath}"></td>
	    <td><a href="${pageContext.request.contextPath}/mobile/${mobile.id}/delete.html">删除</a></td>
	    <td><a href="${pageContext.request.contextPath}/mobile/${mobile.id}/update.html">修改</a></td>
	    <td><a href="${pageContext.request.contextPath}/mobile/${mobile.id}/view.html">详细</a></td>
	    <td><a href="${pageContext.request.contextPath}/mobile/${mobile.id}/download.html">下载</a></td>
	  </tr>
</c:forEach>
</c:if>
  
  <tr>
    <td colspan="10" align="center">
    	<a href="javascript:do_page(1)">首页 </a>
    	<a href="javascript:do_page(${pageInfo.prePage})">上一页 </a>
    	<a href="javascript:do_page(${pageInfo.nextPage})">下一页 </a>
    	<a href="javascript:do_page(${pageInfo.lastPage})">尾页 </a>
    	${pageInfo.pageNum}/${pageInfo.pages}页
      <label>
      <input name="pageNo" type="text" id="pageNo" size="5" />
      <input name="btnGo" type="button" id="btnGo" value="Go" />
    </label></td>
  </tr>
</table>
</body>
</html>

简单的效果图如下