spring-boot-mybatis基于注解

今天看了springboot-mybatis基于注解来编码，总结下来，以便以后查看。有不好嘚嘚地方多多指教。

1.新建一张简单的表

CREATE TABLE `demo` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `NAME` varchar(100) DEFAULT NULL
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

可以随便出入几条数据，方便测试。

2.新建maven项目

工程新建完成，加入pom.xml依赖

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.kfit</groupId>
    <artifactId>spring-boot-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>spring-boot-mybatis</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.1.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- mysql 数据库驱动. -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- spring-boot mybatis依赖： 请不要使用1.0.0版本，因为还不支持拦截器插件， PageHelper 无法支持... -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>

        <!-- 分页插件. 最低是4.1.5 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>4.2.1</version>
        </dependency>


        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>2.11.0</version>
        </dependency>
    </dependencies>
</project>

3.编辑mybatis分页配置类，设置分页属性

import java.util.Properties;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.github.pagehelper.PageHelper;

@Configuration
public class MyBatisConfiguration {
    @Bean
    public PageHelper pageHelper() {
        System.out.println("配置mybatis分页！");
        PageHelper pageHelper = new PageHelper();
        Properties properties = new Properties();
        properties.setProperty("offsetAsPageNum", "true");
        properties.setProperty("rowBoundsWithCount", "true");
        properties.setProperty("reasonable", "true");
        pageHelper.setProperties(properties);
        return pageHelper;
    }
}

4.在application.properties文件配置数据源

配置数据源 连接驱动、账户、密码、最大最小线程

#mysql数据库配置
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username = root
spring.datasource.password = 123
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.max-active = 20
spring.datasource.max-idle = 8
spring.datasource.min-idle = 8
spring.dayasource.initial-size = 10

5.编辑实体类Demo

属性和表字段对应

public class Demo {
    
    private int id;
    private String name;
    //省略方法

}

6.编写SQL和javabean映射接口，DemoMapper

*使用@Ptions配置返回主键信息

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.SelectProvider;
import org.apache.ibatis.annotations.Update;

import com.kfit.demo.bean.Demo;

public interface DemoMapper {

    @Insert("insert into demo(name) values(#{name})")
    @Options(useGeneratedKeys = true, keyProperty = "id", keyColumn = "id")
    public int save(Demo demo);

    @Update("update demo name=#{name} where id=#{id}")
    public int update(Demo demo);

    @Delete("delete from demo where id=#{id}")
    public int delete(int id);

    @Select("select * from demo")
    public List<Demo> selectAll();

}

7.编写服务类，DemoService

使用@Transaction开启事务

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.kfit.demo.bean.Demo;
import com.kfit.demo.mapper.DemoMapper;

@Service
public class DemoService {

    @Autowired
    private DemoMapper demoMapper;

    @Transactional
    public int save(Demo demo) {
        return demoMapper.save(demo);
    }

    @Transactional
    public int update(Demo demo) {
        return demoMapper.update(demo);
    }

    @Transactional
    public int delete(int id) {
        return demoMapper.delete(id);
    }
    
    public List<Demo> selectAll(){
        return demoMapper.selectAll();
    }
}

8.编写控制器，提供访问，DemoController

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.kfit.demo.bean.Demo;
import com.kfit.demo.mapper.DemoMapper;
import com.kfit.demo.service.DemoService;

@RestController
public class DemoController {

    @Autowired
    private DemoService demoService;
    
    @GetMapping("/save")
    public Demo save(Demo demo) {
        int res = demoService.save(demo);
        System.out.println("res-->" + res + "-->id=" + demo.getId());
        return demo;
    }

    @GetMapping("/update")
    public int uodate(Demo demo) {
        return demoService.update(demo);
    }

    @GetMapping("/delete")
    public int delete(int id) {
        return demoService.delete(id);
    }

    @GetMapping("/selectAll")
    public List<Demo> selectAll(int pageNum, int pageSize) {
        PageHelper.startPage(pageNum, pageSize);
        return demoService.selectAll();
    }

}

9.编写启动类，进行测试

需要添加@MapperScan--指定mybatis持久类的位置

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

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

正常情况启动，访问应该是正常。

---

mappper类的sql还可以通过另写一个类来实现
编写DemoSqlProvider

import java.util.Map;

import org.apache.ibatis.jdbc.SQL;

import com.kfit.demo.bean.Demo;

public class DemoSqlProvider {

    public String select7(Demo demo){
        StringBuffer sql = new StringBuffer("select *from demo where 1=1 ");
        if(demo.getName() != null){
            sql.append("and name=#{name} ");
        }
        if(demo.getEmail() != null){
            sql.append("and email=#{email} ");
        }
        return sql.toString();
    }
    
    public String select8(final Demo demo){
        return new SQL(){{
            SELECT("id,name");
            FROM("demo");
            //不需要where 1=1的代码，底层会自动判断.
            //WHERE()方法  ==  XML 使用<where>标签的有等同的效果.
            if(demo.getName() != null){
                WHERE("name=#{name}");
            }
            if(demo.getEmail() != null){
                WHERE("email=#{email}");
            }
        }}.toString();
    }
}

直接在DemoMapper调用

    @SelectProvider(type=DemoSqlProvider.class,method="select7")
    public List<Demo> select7(Demo demo);
    
    @SelectProvider(type=DemoSqlProvider.class,method="select8")
    public List<Demo> select8(Demo demo);

---

以上就是简单的springboot集成mybatis基于注解的方式。