mybatis分頁插件PageHelper使用

時間 2019-12-11

標籤 mybatis 分頁插件 pagehelper 使用欄目 MyBatis 简体版

原文原文鏈接

1、環境

開發工具：ideajava

jdk：1.7mysql

mysql：5git

框架：spring+springmvc+mybatisgithub

使用maven來管理項目spring

2、與ssm整合

第一步：在pom.xml引入PageHelper的依賴

<!-- 引入mybatis的 pagehelper 分頁插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.2</version>
        </dependency>

第二步：在mybatis的全局配置文件中配置PageHelper分頁插件

<?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>
	<!-- 引入 pageHelper插件 -->
	<!--注意這裏要寫成PageInterceptor, 5.0以前的版本都是寫PageHelper, 5.0以後要換成PageInterceptor-->
	<plugins>
		<plugin interceptor="com.github.pagehelper.PageInterceptor">
			<!--reasonable：分頁合理化參數，默認值爲false,直接根據參數進行查詢。
			  當該參數設置爲 true 時，pageNum<=0 時會查詢第一頁， pageNum>pages（超過總數時），會查詢最後一頁。-->
			<!--<property name="reasonable" value="true"/>-->
		</plugin>
	</plugins>
</configuration>

3、使用

例如：實現對用戶的多條件查詢sql

User實體類

package com.szfore.model;

import java.util.Date;
import java.util.List;

public class User {
    private Integer id;

    private String uname;

    private String pwd;

    private String name;

    private Integer sex;

    private String phone;

    private String company;

    private String jobtitle;

    private String birth;

    private Date createdate;

    private Date lastlogintime;

    private List<Role> roleList;

    public List<Role> getRoleList() {
        return roleList;
    }

    public void setRoleList(List<Role> roleList) {
        this.roleList = roleList;
    }

    public Integer getId() {
        return id;
    }

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

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname == null ? null : uname.trim();
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd == null ? null : pwd.trim();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public Integer getSex() {
        return sex;
    }

    public void setSex(Integer sex) {
        this.sex = sex;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone == null ? null : phone.trim();
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company == null ? null : company.trim();
    }

    public String getJobtitle() {
        return jobtitle;
    }

    public void setJobtitle(String jobtitle) {
        this.jobtitle = jobtitle == null ? null : jobtitle.trim();
    }

    public String getBirth() {
        return birth;
    }

    public void setBirth(String birth) {
        this.birth = birth == null ? null : birth.trim();
    }

    public Date getCreatedate() {
        return createdate;
    }

    public void setCreatedate(Date createdate) {
        this.createdate = createdate;
    }

    public Date getLastlogintime() {
        return lastlogintime;
    }

    public void setLastlogintime(Date lastlogintime) {
        this.lastlogintime = lastlogintime;
    }
}

View Code

UserMapper 注意：mapper中就按不分頁的那種寫法就好

package com.szfore.dao;

import com.szfore.model.User;
import com.szfore.model.UserExample;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

@Repository
public interface UserMapper {
    /**
     * 多條件分頁查詢
     * @param userParam
     * @return
     */
    public List<User> queryByPage(User userParam);
}

UserMapper.xml 注意：sql中就不要寫limit了，pageHelp會本身處理，sql就按不分頁的那種寫法就好

<!--多條件分頁查詢用戶-->
  <select id="queryByPage" resultType="com.szfore.model.User">
    SELECT

          *
    FROM
        `user` 
    WHERE
         <if test="id != null and id != ''">
          AND id = #{id}

        </if>
        <if test="uname != null and uname != ''">
          AND uname = #{uname}
        </if>
        <if test="name != null and name != ''">
          AND name like '%${name}%'
        </if>
        <if test="phone != null and phone != ''">
          AND phone like '%${phone}%'
        </if>
        <if test="company != null and company != ''">
          AND company like '%${company}%'
        </if>
        <if test="jobtitle != null and jobtitle != ''">
          AND jobTitle like '%${jobtitle}%'
        </if>
        <if test="birth != null and birth != ''">
          AND birth like '%${birth}%'
        </if>
  </select>

UserServiceImpl

package com.szfore.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.szfore.dao.MenuMapper;
import com.szfore.dao.UserMapper;
import com.szfore.dao.UserRoleMapper;
import com.szfore.model.*;
import com.szfore.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.servlet.http.HttpSession;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class UserServiceImpl implements IUserService{

    @Autowired
    private UserMapper userMapper;
    @Autowired
    private MenuMapper menuMapper;
    @Autowired
    private UserRoleMapper userRoleMapper;
 
    /**
     * 多條件分頁查詢用戶
     * @param userParam
     * @param pageNum
     * @param pageSize
     * @return
     */
    public Json queryByPage(User userParam,Integer pageNum,Integer pageSize) {
        //利用PageHelper分頁查詢 注意：這個必定要放查詢語句的前一行,不然沒法進行分頁,由於它對緊隨其後第一個sql語句有效
        PageHelper.startPage(pageNum, pageSize);
        List<User> userList = userMapper.queryByPage(userParam);
        PageInfo<User> pageInfo = new PageInfo<User>(userList);
        Json json = new Json();
        json.setMsg("成功！");
        json.setObj(pageInfo);
        json.setSuccess(true);
        return json;
    }
}

說明：PageInfo是PageHelper自帶的分頁對象類，詳情以下：數據庫

當前頁
private int pageNum;
每頁的數量
private int pageSize;
當前頁的數量
private int size;
//因爲startRow和endRow不經常使用，這裏說個具體的用法  
//能夠在頁面中"顯示startRow到endRow 共size條數據"  

當前頁面第一個元素在數據庫中的行號
private int startRow;
當前頁面最後一個元素在數據庫中的行號
private int endRow;
總記錄數
private long total;
總頁數
private int pages;
結果集
private List<T> list;

第一頁
private int firstPage;
前一頁
private int prePage;

是否爲第一頁
private boolean isFirstPage = false;
是否爲最後一頁
private boolean isLastPage = false;
是否有前一頁
private boolean hasPreviousPage = false;
是否有下一頁
private boolean hasNextPage = false;
導航頁碼數
private int navigatePages;
全部導航頁號
private int[] navigatepageNums;