Mybatis分頁外掛PageHelper配置及使用方法詳解
阿新 • • 發佈：2020-08-05
環境
框架：spring+springmvc+mybatis
pom.xml
<!-- 引入mybatis的 pagehelper 分頁外掛 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.1.2</version>
</dependency>
配置全域性配置檔案
在mybatis的全域性配置檔案中配置PageHelper分頁外掛
<?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外掛 -->
<!--注意這裡要寫成PageInterceptor,5.0之前的版本都是寫PageHelper,5.0之後要換成PageInterceptor-->
<plugins>
<plugin interceptor="com.github.pagehelper.PageInterceptor">
<!--reasonable：分頁合理化引數，預設值為false,直接根據引數進行查詢。
當該引數設定為 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>使用
例如：實現對使用者的多條件查詢
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;
}
}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會自己處理，sql就按不分頁的那種寫法就好
<!--多條件分頁查詢使用者-->
<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> </WHERE>
</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;
/**
* 多條件分頁查詢使用者
* @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：這個一定要放查詢語句的前一行,否則無法進行分頁,因為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自帶的分頁物件類，詳情如下：
當前頁
private int pageNum;
每頁的數量
private int pageSize;
當前頁的數量
private int size;
//由於startRow和endRow不常用，這裡說個具體的用法
//可以在頁面中"顯示startRow到endRow 共size條資料"當前頁面第一個元素在資料庫中的行號
private int startRow;
當前頁面最後一個元素在資料庫中的行號
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;是否為第一頁
private boolean isFirstPage = false;
是否為最後一頁
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;
所有導航頁號
private int[] navigatepageNums;
通過PageInfo獲取其他資訊
PageHelper.startPage(req.getCurrentPage(),req.getPageSize(),true);
List<SecurityRiskLibary> list=securityRiskLibaryDAO.queryList(srl);
PageInfo page=new PageInfo(list);
page.getTotal();
page.xxxx
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