目录
方式1
一、准备工作
1. 创建表结构
2. 导入表数据
3. 导入pom.xml依赖
4. 配置application.yml文件
5. 创建公用的实体类
项目结构
2. 创建controller层
3. 创建service层
4. 创建mapper层
5. 创建xml文件
6. 使用postman进行测试，测试结果如下
1. 项目整体结构
1. 创建controller层
2. 创建Service层
3. 创建Mapper层
5. 编写xml文件
三、借助MyBatis提供的第三方PageHelper分页插件2
1. 依赖pom.xml
2. 配置application.properties
3. 实现分页功能
四、借助MyBatis-Plus拦截器进行分页查询
1. 项目整体结构
2. 编写主配置类
3. 创建controller层
4. 创建Service层
5. 创建Mapper层
6. 使用postman进行测试，测试结果如下
五、借助MyBabtis提供的RowBounds进行分页查询
1. 项目整体结构
2. 创建controller层
3. 创建Service层
4. 创建Mapper层
5. 创建xml文件
6. 使用postman进行测试，测试结果如下
方式1
一、准备工作
1. 创建表结构
CREATE TABLE `order_info` (
`id` int NOT NULL AUTO_INCREMENT,
`info` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`time` datetime NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 14 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;2. 导入表数据
INSERT INTO `order_info` VALUES (1, '购买了手机', '2022-08-25 05:34:17');
INSERT INTO `order_info` VALUES (2, '购买了电脑', '2022-08-25 07:30:39');
INSERT INTO `order_info` VALUES (3, '购买了护手霜', '2022-08-17 22:35:07');
INSERT INTO `order_info` VALUES (4, '购买了泡面', '2022-08-23 08:35:36');
INSERT INTO `order_info` VALUES (5, '购买了纸巾', '2022-07-21 15:26:06');
INSERT INTO `order_info` VALUES (6, '购买了自热米饭', '2021-06-20 13:21:06');
INSERT INTO `order_info` VALUES (7, '购买了移动硬盘', '2022-06-11 11:22:03');
INSERT INTO `order_info` VALUES (8, '购买了狗粮', '2022-05-10 11:21:02');
INSERT INTO `order_info` VALUES (9, '购买了猫粮', '2022-04-10 09:11:02');
INSERT INTO `order_info` VALUES (10, '购买了遥控器', '2022-08-22 22:35:07');
INSERT INTO `order_info` VALUES (11, '购买了裤子', '2022-08-15 08:35:36');
INSERT INTO `order_info` VALUES (12, '购买了鞋子', '2022-08-21 08:35:36');
INSERT INTO `order_info` VALUES (13, '购买了水杯', '2022-08-26 19:39:19');3. 导入pom.xml依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--Mybatis依赖-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.2.2</version>
</dependency>
<!--PageHelper依赖-->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.4.3</version>
</dependency>
<!--Mybatis-Plus依赖-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.2</version>
</dependency>
</dependencies>4. 配置application.yml文件
server:
port: 8080
spring:
datasource:
username: 你的mysql用户名
password: 你的mysql密码
url: jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
mapper-locations: classpath:mapping/*.xml5. 创建公用的实体类
import java.util.Date;
public class OrderInfo {
private int id;
private String info;
private Date time;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
public Date getTime() {
return time;
}
public void setTime(Date time) {
this.time = time;
}
@Override
public String toString() {
return "OrderInfo{" +
"id=" + id +
", info='" + info + '\'' +
", time=" + time +
'}';
}
}项目结构
2. 创建controller层
package com.ithuang.demo.controller;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.service.OrderInfoService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.List;
@RestController
public class OrderInfoController {
@Resource
private OrderInfoService orderInfoService;
@GetMapping("/getOrderInfoList")
public List<OrderInfo> getOrderInfoList(@RequestParam(value = "pageNow",defaultValue = "1") int pageNow,
@RequestParam(value = "pageSize",defaultValue = "3") int pageSize){
return orderInfoService.getOrderInfoList(pageNow,pageSize);
}
}3. 创建service层
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.mapper.OrderInfoMapper;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class OrderInfoService {
@Resource
private OrderInfoMapper orderInfoMapper;
public List<OrderInfo> getOrderInfoList(int pageNow, int pageSize) {
if(pageNow == 1){
pageNow = 0;
}
return orderInfoMapper.getOrderInfoList(pageNow,pageSize);
}
}4. 创建mapper层
package com.ithuang.demo.mapper;
import com.ithuang.demo.bean.OrderInfo;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface OrderInfoMapper {
List<OrderInfo> getOrderInfoList(@Param("pageNow") int pageNow,@Param("pageSize") int pageSize);
}5. 创建xml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.ithuang.demo.mapper.OrderInfoMapper">
<select id="getOrderInfoList" parameterType="int" resultType="com.ithuang.demo.bean.OrderInfo">
SELECT * FROM order_info limit #{pageNow},#{pageSize}
</select>
</mapper>6. 使用postman进行测试，测试结果如下
在MyBatis中配置了分页拦截器（PageInterceptor），就是在执行相关的Sql之前会做一些拦截的操作，这里通过调用startPage的方法，其实就是在查询getOrderInfoList之前会自动加上limit；这里通过setLocalPage方法，将分页信息保存在当前之后线程当中，查询方法与之处于同一个线程，共享ThreadLocal当中的数据，最后将getOrderInfoList查询好的数据结果放到PageInfo当中即可。
扩展：PageHelper.startPage(int PageNum,int PageSize):用来设置页面的位置和展示的数据条目数，我们设置每页展示5条数据。PageInfo用来封装页面信息，返回给前台界面。PageInfo中的一些我们需要用到的参数如下表：
PageInfo.list 结果集
PageInfo.pageNum 当前页码
PageInfo.pageSize 当前页面显示的数据条目
PageInfo.pages 总页数
PageInfo.total 数据的总条目数
PageInfo.prePage 上一页
PageInfo.nextPage 下一页
PageInfo.isFirstPage 是否为第一页
PageInfo.isLastPage 是否为最后一页
PageInfo.hasPreviousPage 是否有上一页
PageHelper.hasNextPage 是否有下一页
（1）引入pom.xml
<!-- 分页插件 --> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version>1.2.5</version> </dependency>（2）打开application.properties，添加如下几行配置信息
#分页插件 pagehelper.helper-dialect=mysql pagehelper.params=count=countSql pagehelper.reasonable=true pagehelper.support-methods-arguments=true
1. 项目整体结构
1. 创建controller层
Mapper文件中, SQL不用增加 limit分页指令,需要什么直接查就可以,Pagehelper 可以自动实现分页
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.service.OrderInfoService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.List;
@RestController
public class OrderInfoController {
@Resource
private OrderInfoService orderInfoService;
@GetMapping("/getOrderInfoList")
public List<OrderInfo> getOrderInfoList(@RequestParam(value = "pageNow",defaultValue = "1") int pageNow,
@RequestParam(value = "pageSize",defaultValue = "3") int pageSize){
return orderInfoService.getOrderInfoList(pageNow,pageSize);
}
}2. 创建Service层
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.mapper.OrderInfoMapper;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class OrderInfoService {
@Resource
private OrderInfoMapper orderInfoMapper;
public List<OrderInfo> getOrderInfoList(int pageNow, int pageSize) {
PageHelper.startPage(pageNow,pageSize);
List<OrderInfo> orderInfoList = orderInfoMapper.getOrderInfoList();
PageInfo<OrderInfo> userPageInfo = new PageInfo<>(orderInfoList);
return userPageInfo.getList();
}
}3. 创建Mapper层
import com.ithuang.demo.bean.OrderInfo;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface OrderInfoMapper {
List<OrderInfo> getOrderInfoList();
}5. 编写xml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.ithuang.demo.mapper.OrderInfoMapper">
<select id="getOrderInfoList" parameterType="int" resultType="com.ithuang.demo.bean.OrderInfo">
SELECT * FROM order_info
</select>
</mapper>三、借助MyBatis提供的第三方PageHelper分页插件2
1. 依赖pom.xml
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.2.0</version>
</dependency>2. 配置application.properties
#分页插件
pagehelper.helper-dialect=mysql
pagehelper.params=count=countSql
pagehelper.reasonable=true
pagehelper.support-methods-arguments=true3. 实现分页功能
①首页超链接
<a th:href="@{/get/page/1}">显示分页数据</a>②controller方法
@RequestMapping("/get/page/{pageNo}")
public String getPage(
@PathVariable("pageNo") Integer pageNo,
Model model) {
// PageInfo 对象封装了和分页相关的所有信息
PageInfo<Emp> pageInfo = empService.getPageInfo(pageNo);
// 将 PageInfo 对象存入模型
model.addAttribute("pageInfo", pageInfo);
return "emp-page";
}③service 方法
@Override
public PageInfo<Emp> getPageInfo(Integer pageNo) {
// 1、确定每页显示数据的条数
int pageSize = 5;
// 2、设定分页数据：开启分页功能。开启后，后面执行的 SELECT 语句会自动被附加 LIMIT 子句，
// 而且会自动查询总记录数
PageHelper.startPage(pageNo, pageSize);
// 3、正常执行查询
List<Emp> empList = empMapper.selectAll();
// 4、封装为 PageInfo 对象返回
return new PageInfo<>(empList);
}④页面展示
<tr>
<td colspan="5">
<span th:each="targetNum : ${pageInfo.navigatepageNums}">
<!-- 不是当前页显示为超链接 -->
<a th:if="${targetNum != pageInfo.pageNum}"
th:href="@{/employee/page/}+${targetNum}"
th:text="'['+${targetNum}+']'">目标页面的页码</a>
<!-- 是当前页不需要显示为超链接 -->
<span th:if="${targetNum == pageInfo.pageNum}" th:text="'['+${targetNum}+']'">当前页页码</span>
</span>
</td>
</tr>
<tr>
<td colspan="5">
<span th:if="${pageInfo.hasPreviousPage}">
<a th:href="@{/employee/page/1}">首页</a>
<a th:href="@{/employee/page/}+${pageInfo.prePage}">上一页</a>
</span>
[[${pageInfo.pageNum}]]/[[${pageInfo.pages}]]
[[${pageInfo.pageNum}+'/'+${pageInfo.pages}]]
<span th:if="${pageInfo.hasNextPage}">
<a th:href="@{/employee/page/}+${pageInfo.nextPage}">下一页</a>
<a th:href="@{/employee/page/}+${pageInfo.pages}">末页</a>
</span>
</td>
</tr>
<tr>
<td colspan="5">
<!-- 绑定值改变事件响应函数 -->
<input id="jumpToPageNumInput" type="text" name="jumpToPageNum" placeholder="请输入您想直接跳转的页码" />
</td>
</tr>四、借助MyBatis-Plus拦截器进行分页查询
1. 项目整体结构
2. 编写主配置类
package com.ithuang.demo.config;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MybatisPlusConfig {
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor(){
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
return interceptor;
}
}3. 创建controller层
package com.ithuang.demo.controller;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.service.OrderInfoService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.List;
@RestController
public class OrderInfoController {
@Resource
private OrderInfoService orderInfoService;
@GetMapping("/getOrderInfoList")
public List<OrderInfo> getOrderInfoList(@RequestParam(value = "pageNow",defaultValue = "1") int pageNow,
@RequestParam(value = "pageSize",defaultValue = "3") int pageSize){
return orderInfoService.getOrderInfoList(pageNow,pageSize);
}
}4. 创建Service层
package com.ithuang.demo.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.mapper.OrderInfoMapper;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class OrderInfoService {
@Resource
private OrderInfoMapper orderInfoMapper;
public List<OrderInfo> getOrderInfoList(int pageNow, int pageSize) {
Page<OrderInfo> page= new Page<>(pageNow,pageSize);
IPage<OrderInfo> iPage = orderInfoMapper.selectPage(page,null);
return iPage.getRecords();
}
}5. 创建Mapper层
package com.ithuang.demo.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.ithuang.demo.bean.OrderInfo;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface OrderInfoMapper extends BaseMapper<OrderInfo> {
}6. 使用postman进行测试，测试结果如下
五、借助MyBabtis提供的RowBounds进行分页查询
RowBounds它是在SQL执行的结果进行截取分页的，所以不适合大量数据的截取和分页，它适合在查询较少的结果集当中使用。
1. 项目整体结构
2. 创建controller层
package com.ithuang.demo.controller;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.service.OrderInfoService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.List;
@RestController
public class OrderInfoController {
@Resource
private OrderInfoService orderInfoService;
@GetMapping("/getOrderInfoList")
public List<OrderInfo> getOrderInfoList(@RequestParam(value = "pageNow",defaultValue = "1") int pageNow,
@RequestParam(value = "pageSize",defaultValue = "3") int pageSize){
return orderInfoService.getOrderInfoList(pageNow,pageSize);
}
}3. 创建Service层
package com.ithuang.demo.service;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.mapper.OrderInfoMapper;
import org.apache.ibatis.session.RowBounds;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class OrderInfoService {
@Resource
private OrderInfoMapper orderInfoMapper;
public List<OrderInfo> getOrderInfoList(int pageNow, int pageSize) {
RowBounds rowBounds = new RowBounds(pageNow,pageSize);
return orderInfoMapper.getOrderInfoList(rowBounds);
}
}4. 创建Mapper层
package com.ithuang.demo.mapper;
import com.ithuang.demo.bean.OrderInfo;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.session.RowBounds;
import java.util.List;
@Mapper
public interface OrderInfoMapper {
List<OrderInfo> getOrderInfoList(RowBounds rowBounds);
}5. 创建xml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.ithuang.demo.mapper.OrderInfoMapper">
<select id="getOrderInfoList" resultType="com.ithuang.demo.bean.OrderInfo">
SELECT * FROM order_info
</select>
</mapper>6. 使用postman进行测试，测试结果如下
