按照官方文档进行的配置：快速开始|mybatis-plus
引入依赖：
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<!-- 引入mybatisPlus -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.2.0</version>
</dependency>
<!-- 引入mysql驱动包 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.27</version>
</dependency>
<!-- 引入Druid依赖，阿里巴巴所提供的数据源 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.29</version>
</dependency>
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在application.yml配置
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spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8
username: root
password: 123456
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在启动类上面添加@MapperScan注解，扫描mapper包
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@SpringBootApplication
@MapperScan("com.qiao.demo02.mapper")
public class SpringbootDemo02Application {
public static void main(String[] args) {
SpringApplication.run(SpringbootDemo02Application.class, args);
}
}
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新建User和UserMapper
user类
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@Data
public class User {
@TableId
private Integer userId;
private String userName;
private Integer userAge;
private String userEmail;
}
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UserMapper接口
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public interface UserMapper extends BaseMapper<User> {
}
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最重要的是继承BaseMapper<E>接口：里面声明了很强大的CRUD方法
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public interface BaseMapper<T> extends Mapper<T> {
int insert(T entity);
int deleteById(Serializable id);
int deleteByMap(@Param("cm") Map<String, Object> columnMap);
int delete(@Param("ew") Wrapper<T> wrapper);
int deleteBatchIds(@Param("coll") Collection<? extends Serializable> idList);
int updateById(@Param("et") T entity);
int update(@Param("et") T entity, @Param("ew") Wrapper<T> updateWrapper);
T selectById(Serializable id);
List<T> selectBatchIds(@Param("coll") Collection<? extends Serializable> idList);
List<T> selectByMap(@Param("cm") Map<String, Object> columnMap);
T selectOne(@Param("ew") Wrapper<T> queryWrapper);
Integer selectCount(@Param("ew") Wrapper<T> queryWrapper);
List<T> selectList(@Param("ew") Wrapper<T> queryWrapper);
List<Map<String, Object>> selectMaps(@Param("ew") Wrapper<T> queryWrapper);
List<Object> selectObjs(@Param("ew") Wrapper<T> queryWrapper);
IPage<T> selectPage(IPage<T> page, @Param("ew") Wrapper<T> queryWrapper);
IPage<Map<String, Object>> selectMapsPage(IPage<T> page, @Param("ew") Wrapper<T> queryWrapper);
}
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这点官方文档讲的也很详细：https://mp.baomidou.com/guide/page.html
新建一个config包，在里面建一个MybatisPlus配置类 返回一个分页拦截器
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package com.qiao.demo02.config;
@Configuration
@ConditionalOnClass(value = {PaginationInterceptor.class})
public class MybatisPlusConfig {
@Bean
public PaginationInterceptor paginationInterceptor() {
PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
return paginationInterceptor;
}
}
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这样就能使用mybatis的分页功能了
Junit测试
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@Resource
private UserMapper userMapper;
@Test
public void queryUserForPage(){
IPage<User> userPage = new Page<>(2, 2);//参数一是当前页，参数二是每页个数
userPage = userMapper.selectPage(userPage, null);
List<User> list = userPage.getRecords();
for(User user : list){
System.out.println(user);
}
}
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Controller返回json串
先定义一个包装类UserVo，用来保存分页所需要的数据
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package com.qiao.demo02.vo;
@Data
public class UserVo {
private Integer current;
private Integer size;
private Long total;
private List<User> userList;
}
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然后在控制器编写代码，这里省略了service层，实际开发业务代码写在service层，Controller只负责：接受参数、调用service层方法处理业务逻辑，返回结果
Controller类贴上了@RestController注解
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@GetMapping("queryUser")
public UserVo queryList(Integer current, Integer size) {
/**
* 这些代码应该写在service层
*/
UserVo userVo = new UserVo();
IPage<User> page = new Page<>(current, size);
userMapper.selectPage(page, null);
userVo.setCurrent(current);
userVo.setSize(size);
userVo.setTotal(page.getTotal());
userVo.setUserList(page.getRecords());
return userVo;
}
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