用完spring-data-jpa之后并不是很想用mybatis,但是没办法呀，大环境还是mybatis，而且现在mybatis也出了不少插件，我们还是一起看看如何整合mybatis吧 关于整合mybatis有两种方式，一种是注解方式，另一种是传统的xml方式

注解方式

先看看引入的依赖

    <dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.2</version></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></dependencies>
复制代码

sql文件

CREATE TABLE `test`.`Untitled`  (`id` int(11) NOT NULL AUTO_INCREMENT,`name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,`passwd` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
复制代码

application.properties

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql:///test?useSSL=true
spring.datasource.username=root
spring.datasource.password=root#打印sql语句到控制台
logging.level.com.priv.gabriel.demoformybatis.mapper=debug复制代码

User.java

package com.priv.gabriel.demoformybatis.entity;/*** Created with Intellij IDEA.** @Author: Gabriel* @Date: 2018-10-14* @Description:*/
public class User {private long id;private String username;private String passwd;public long getId() {return id;}public void setId(long id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPasswd() {return passwd;}public void setPasswd(String passwd) {this.passwd = passwd;}
}
复制代码

UserMapper.java

package com.priv.gabriel.demoformybatis.mapper;import com.priv.gabriel.demoformybatis.entity.User;
import org.apache.ibatis.annotations.*;/*** Created with Intellij IDEA.** @Author: Gabriel* @Date: 2018-10-14* @Description:*/
@Mapper
public interface UserMapper {/*注解方式的话直接在方法上写上对应的sql语句就可以了*/@Select("select * from user where id = #{id}")/*如果需要重复使用该Result,给该Results加一个 id 属性，下面即可使用@ResultMap(id)重复调用*/@Results(id = "user",value = {@Result(property = "username",column = "name")})User findById(long id);/*获取回传自增id*//*id会自动存入user中*/@Insert("insert into user(name,passwd) values (#{username},#{passwd})")@Options(useGeneratedKeys = true,keyProperty = "id")int inertUser(User user);
}复制代码

UserController.java

package com.priv.gabriel.demoformybatis.controller;import com.priv.gabriel.demoformybatis.entity.User;
import com.priv.gabriel.demoformybatis.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;import java.util.List;/*** Created with Intellij IDEA.** @Author: Gabriel* @Date: 2018-10-14* @Description:*/
@RestController
@RequestMapping("/users")
public class UserController {@Autowiredprivate UserMapper userMapper;@RequestMapping(value = "/{id}",method = RequestMethod.GET)public User selectById(@PathVariable long id){return userMapper.findById(id);}@RequestMapping(value = {""},method = RequestMethod.POST)public String addUser(User user){userMapper.inertUser(user);return "现在自增id为"+user.getId();}
}复制代码

在SpringBoot1.x中还需要在启动类中加入@MapperScan("mapper所在目录"),而在2.x版本中不需要加入就可以自动扫描到mapper了

加入分页

需要引入pageHelper依赖

        <!-- 引入分页插件 --><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>1.2.5</version></dependency>
复制代码

在UserMapper中新增一个查询所有信息的方法

    @Select("select * from user")/*调用之前的Results*/@ResultMap("user")List<User> listUser();
复制代码

在Controller中调用

    /*获取分页数据 包含分页详细信息*/@RequestMapping(value = "/",method = RequestMethod.GET)public PageInfo getAll(@RequestParam Integer page, @RequestParam Integer size){PageHelper.startPage(page,size);List<User> users = userMapper.listUser();PageInfo<User> pageInfo = new PageInfo(users);return pageInfo;}/*仅获取分页数据@RequestMapping(value = "/",method = RequestMethod.GET)public List<User> getAll(@RequestParam Integer page, @RequestParam Integer size){PageHelper.startPage(page,size);List<User> users = userMapper.listUser();return users;}*/
复制代码

XML方式

xml方式的话和以前Spring整合mybatis没有太大的区别，在这里可以使用Mybatis-Generator自动生成代码少些一点代码，其余的话就不多介绍了

整合通用Mapper

不管是使用注解方式还是XML方式都还是会存在一个什么都得自己动手的情况，接下来的话，我们整合一个通用的Mapper，在mybatis中体验jpa的感觉 引用依赖

<!-- 引入通用mapper --><dependency><groupId>tk.mybatis</groupId><artifactId>mapper-spring-boot-starter</artifactId><version>2.0.4</version></dependency>
复制代码

继承BaseMapper

package com.priv.gabriel.demoformybatis.mapper;import com.priv.gabriel.demoformybatis.entity.User;
import org.apache.ibatis.annotations.Mapper;
import tk.mybatis.mapper.common.BaseMapper;/*** Created with Intellij IDEA.** @Author: Gabriel* @Date: 2018-10-14* @Description:*/
@Mapper
public interface UserCommonMapper extends BaseMapper<User> {
}复制代码

接着在Controller中调用

   @Autowiredprivate UserCommonMapper mapper;@RequestMapping("/testCommonMapperForSelectAll")public List<User> testCommonMapper(){return mapper.selectAll();}
复制代码

关于mybatis的扩展很多，还有像mybatis-plus，关于这个话有时间再说吧，ε=ε=ε=┏(゜ロ゜;)┛