10—mybatis通用mapper插件 pagehelper 分页 _通用mapper

犀渠玉剑良家子，白马金羁侠少年。这篇文章主要讲述10—mybatis通用mapper插件 pagehelper 分页相关的知识，希望能为你提供帮助。
spring boot真的太好用了，大家以后多多使用，今天来说说pagehelper 来做mybatis分页，我用的是spring boot 做的开发，后面会把源码发出来。
pagehelper（https://github.com/pagehelper/Mybatis-PageHelper）是什么我就不多说了，网上太多太多了。
还是上代码吧
Card表

CREATE TABLE `card` ( `id` int(11) NOT NULL DEFAULT \'0\', `cid` int(11) DEFAULT NULL, `title` varchar(60) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `card` VALUES (\'1\', \'2\', \'aldsjkfla\'); INSERT INTO `card` VALUES (\'2\', \'3\', \'2222aldsjkfla\'); INSERT INTO `card` VALUES (\'3\', \'1\', \'2323\'); INSERT INTO `card` VALUES (\'4\', \'4\', \'4444444444\'); INSERT INTO `card` VALUES (\'5\', \'5\', \'55555555555555\'); INSERT INTO `card` VALUES (\'6\', \'6\', \'66666666666666\'); INSERT INTO `card` VALUES (\'7\', \'7\', \'77777777777777\'); INSERT INTO `card` VALUES (\'8\', \'8\', \'88888888888888888888\'); INSERT INTO `card` VALUES (\'9\', \'9\', \'999999999999999999\'); INSERT INTO `card` VALUES (\'10\', \'10\', \'swswswsws\'); INSERT INTO `card` VALUES (\'11\', \'11\', \'112121222222\'); INSERT INTO `card` VALUES (\'12\', \'12\', \'aaaaaa\'); INSERT INTO `card` VALUES (\'13\', \'13\', \'asdfasdfadfadfadsf\'); INSERT INTO `card` VALUES (\'14\', \'14\', \'aswsweerererer\'); INSERT INTO `card` VALUES (\'15\', \'15\', \'dfdfdfdfdfa\'); INSERT INTO `card` VALUES (\'16\', \'16\', \'dfdsfsadf\'); INSERT INTO `card` VALUES (\'17\', \'17\', \'agtgtgtgtg\'); INSERT INTO `card` VALUES (\'18\', \'18\', \'aaaggtgtg\');

【10—mybatis通用mapper插件 pagehelper 分页】
下面开始编码：
1.新建一个spring boot项目

文章图片

2.导包
pom.xml

< ?xml version="1.0" encoding="UTF-8"?> < project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> < modelVersion> 4.0.0< /modelVersion> < parent> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-parent< /artifactId> < version> 2.2.1.RELEASE< /version> < relativePath/> < !-- lookup parent from repository --> < /parent> < groupId> org.zn.test< /groupId> < artifactId> testpage< /artifactId> < version> 0.0.1-SNAPSHOT< /version> < name> testpage< /name> < description> Demo project for Spring Boot< /description> < properties> < java.version> 1.8< /java.version> < /properties> < dependencies> < dependency> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-web< /artifactId> < /dependency> < dependency> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-test< /artifactId> < scope> test< /scope> < exclusions> < exclusion> < groupId> org.junit.vintage< /groupId> < artifactId> junit-vintage-engine< /artifactId> < /exclusion> < /exclusions> < /dependency> < !--自动构造java--> < dependency> < groupId> org.projectlombok< /groupId> < artifactId> lombok< /artifactId> < version> 1.14.8< /version> < /dependency> < !--通用mapper启动器--> < dependency> < groupId> tk.mybatis< /groupId> < artifactId> mapper-spring-boot-starter< /artifactId> < version> 2.0.4< /version> < /dependency> < !--分页助手启动器--> < dependency> < groupId> com.github.pagehelper< /groupId> < artifactId> pagehelper-spring-boot-starter< /artifactId> < version> 1.2.5< /version> < /dependency> < !--mysql--> < dependency> < groupId> mysql< /groupId> < artifactId> mysql-connector-java< /artifactId> < version> 5.1.32< /version> < /dependency> < /dependencies> < build> < plugins> < plugin> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-maven-plugin< /artifactId> < /plugin> < /plugins> < /build> < /project>

3. 配置文件，包括数据地址等信息
application.yml

server: port: 8099 spring: application: name: testpage datasource: url: jdbc:mysql://localhost:3306/card username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver#显示sql语句 mybatis: configuration: log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

4.建立实体类 Card.java

package org.zn.test.testpage.entity; import lombok.Data; import lombok.ToString; import tk.mybatis.mapper.annotation.KeySql; import javax.persistence.Id; import javax.persistence.Table; @Table(name = "card") @Data @ToString public class Card { @Id @KeySql(useGeneratedKeys = true) private Integer id; private Integer cid; private String title; }

5.建立Mapper
CardMapper.java，这里注意用是通用mapper来实现的，所有继承tk.mybatis.mapper.common.Mapper的Mapper

package org.zn.test.testpage.mapper; import org.zn.test.testpage.entity.Card; import tk.mybatis.mapper.common.Mapper; public interface CardMapper extends Mapper< Card> {}

6.建立Servcie
CardService.java

package org.zn.test.testpage.service;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.zn.test.testpage.entity.Card;
import org.zn.test.testpage.mapper.CardMapper;
import tk.mybatis.mapper.entity.Example;

import java.util.List;

@Service
public class CardService {
@Autowired
private CardMapper cardMapper;

public List< Card> GetPageList(Integer page,Integer rows,String sortBy,Boolean desc,String key)
{
//分页
PageHelper.startPage(page,rows);
//过滤
Example example=new Example(Card.class);
if(key!=""& & !key.equals("")){
example.createCriteria().orLike("title","%"+key+"%");
}
//排序
if(sortBy!=""& & !key.equals("")){
String orderByClause=sortBy+(desc?" DESC":" ASC");
example.setOrderByClause(orderByClause);
}
//查询
List< Card> list=cardMapper.selectByExample(example);
PageInfo< Card> info=new PageInfo< Card> (list);
return info.getList();
}

}

7.建立Controller
HomeController.java

package org.zn.test.testpage.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import org.zn.test.testpage.entity.Card; import org.zn.test.testpage.service.CardService; import java.util.List; @RestController @RequestMapping("/home") public class HomeController { @Autowired private CardService cardService; @RequestMapping("/index") public String Index(int page,String key) { List< Card> list = cardService.GetPageList(page, 5, "id", true, key); StringBuilder sb = new StringBuilder(); for (Card item : list) { sb.append(item+"< /br> "); } return sb.toString(); }}

8.配置启动类
TestpageApplication.java 就是spring boot启动类，要注意这里用@MapperScan("org.zn.test.testpage.mapper")，进入整包注入。

package org.zn.test.testpage; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import tk.mybatis.spring.annotation.MapperScan; @SpringBootApplication @MapperScan("org.zn.test.testpage.mapper") public class TestpageApplication { public static void main(String[] args) { SpringApplication.run(TestpageApplication.class, args); }}

9.启动，并访问
http://localhost:8099/home/index?page=1& key=a