Spring boot集成 MyBatis 通用Mapper

配置

POM文件

<parent>
<groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.6.RELEASE</version>
    <relativePath />
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>tk.mybatis</groupId>
        <artifactId>mapper-spring-boot-starter</artifactId>
        <version>RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper-spring-boot-starter</artifactId>
        <version>RELEASE</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

同一环境1.5.7.RELEASE版本的Spring-boot会抛Caused by: java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver异常，1.5.6.RELEASE以及1.5.5.RELEASE版本亲测没问题

---

application.properties配置文件

#数据库
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=741852
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#mybatis&&通用Mapper
mybatis.type-aliases-package=com.karle.bean
mybatis.mapper-locations=classpath:mapper/*.xml
mapper.mappers=com.karle.tk.TkMapper
mapper.identity=MYSQL

#分页插件
pagehelper.helperDialect=mysql
pagehelper.reasonable=true
pagehelper.supportMethodsArguments=true
pagehelper.params=count=countSql

#log
logging.file=logger.log
logging.level.*=debug

映射实体（省略字段get、set）

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Table(name = "user")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    /**
     * 名称
     */
    @Column(name = "name")
    private String name;

    /**
     * 年龄
     */
    @Column(name = "age")
    private Integer age;

    /**
     * 身份编号
     */
    @Column(name = "card_no")
    private Integer cardNo;

    /**
     * 生日
     */
    @Column(name = "birthday")
    private Date birthday;
}

本地通用Mapper接口（继承通用Mapper接口）

import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;

public interface TkMapper<T> extends Mapper<T>, MySqlMapper<T> {

}

Mapper接口：基本的增、删、改、查方法 
MySqlMapper：针对MySQL的额外补充接口，支持批量插入

业务接口（继承“本地通用Mapper接口”）

import org.apache.ibatis.annotations.Param;

import com.karle.bean.User;
import com.karle.tk.TkMapper;

public interface UserMapper extends TkMapper<User> {

    public User selectByCardNo(@Param("cardNo") int cardNo);

}

Spring-boot启动类，@MapperScan仅扫描业务接口包，不能扫描本地通用Mapper接口包，否则报java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class异常

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan(basePackages = { "com.karle.mapper" })
public class SpringBootMyBatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootMyBatisApplication.class, args);
    }

}

通过使用@MapperScan可以指定要扫描的Mapper类的包的路径，比如：

@SpringBootApplication
@MapperScan("com.kfit.*.mapper")
public class App {
    public static void main(String[] args) {
       SpringApplication.run(App.class, args);
    }
}

或者：

@SpringBootApplication
@MapperScan("com.kfit.mapper")
public class App {
    public static void main(String[] args) {
       SpringApplication.run(App.class, args);
    }
}

       可以根据包的结构指定不同的表达式。

使用@MapperScan注解多个包

可以使用如下的方式指定多个包：

@SpringBootApplication
@MapperScan({"com.kfit.demo","com.kfit.user"})
public class App {
    public static void main(String[] args) {
       SpringApplication.run(App.class, args);
    }
}

       如果mapper类没有在Spring Boot主程序可以扫描的包或者子包下面，可以使用如下方式进行配置：

@SpringBootApplication
@MapperScan({"com.kfit.*.mapper","org.kfit.*.mapper"})
public class App {
    public static void main(String[] args) {
       SpringApplication.run(App.class, args);
    }
}

单元测试

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import com.github.pagehelper.PageHelper;
import com.karle.bean.User;
import com.karle.mapper.UserMapper;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootMyBatisApplicationTests {

    @Autowired
    private UserMapper mapper;

    // 插入一条新记录
    @Test
    public void insertOne() {
        User newUser = new User();
        int cardNo = (int) (Math.random() * 10000000);
        newUser.setAge(24);
        newUser.setBirthday(new Date());
        newUser.setName(cardNo + "用户");
        newUser.setCardNo(cardNo);
        mapper.insertSelective(newUser);
        System.out.println("插入成功");
    }

    // 批量插入记录
    @Test
    public void insertMore() {
        List<User> recordList = new ArrayList<User>();
        for (int i = 0; i < 2; i++) {
            User newUser = new User();
            int cardNo = (int) (Math.random() * 10000000);
            newUser.setAge(26);
            newUser.setBirthday(new Date());
            newUser.setName(cardNo + "批量插入用户");
            newUser.setCardNo(cardNo);
            recordList.add(newUser);
        }
        mapper.insertList(recordList);
        System.out.println("批量插入成功");
    }

    // 根据唯一编号查询用户(通用Mapper查询)
    @Test
    public void selectByCardNo() {
        User paramBean = new User();
        paramBean.setCardNo(6647403);
        User dbUser = mapper.selectOne(paramBean);
        if (dbUser != null) {
            System.out.println("数据库用户(通用Mapper查询)：" + dbUser.getName());
            return;
        }
        System.out.println("查无此用户");
    }

    // 根据唯一编号查询用户(XML查询)
    @Test
    public void selectByCardNoByXml() {
        User dbUser = mapper.selectByCardNo(6105967);
        if (dbUser != null) {
            System.out.println("数据库用户(XML查询)：" + dbUser.getName());
            return;
        }
        System.out.println("查无此用户");
    }

    // 根据年龄查询一组用户
    @Test
    public void selectByAge() {
        User paramBean = new User();
        paramBean.setAge(24);
        List<User> dbUserList = mapper.select(paramBean);
        System.out.println("总共查询数：" + dbUserList.size());
    }

    // 分页查询用户
    @Test
    public void selectByPage() {
        PageHelper.offsetPage(1, 5);
        List<User> dbUserList = mapper.select(null);
        for (User item : dbUserList) {
            System.out.println("分页用户：" + item.getName());
        }
    }

    // 更新用户信息
    @Test
    public void updateOneInfo() {
        User paramBean = new User();
        paramBean.setId(1);
        paramBean.setAge(26);
        mapper.updateByPrimaryKeySelective(paramBean);
        System.out.println("更新成功");
    }

}

事物的使用

spring Boot 使用事务非常简单，首先使用注解 @EnableTransactionManagement开启事务支持后，然后在访问数据库的Service方法上添加注解 @Transactional 便可。

@EnableTransactionManagement放在启动类上