spring-boot和mybatis的整合

时间 2019-11-06

原文原文链接

在idea里建立一个spring-boot工程选依赖的时候把web里的web勾上，sql里的mysql和mybatis也勾上，这样就会自动帮咱们生成依赖在其中咱们须要给mysql的依赖加上版本，否则它会自动去用最新版的（目前mysql最新版已经到了八以上了），咱们如今用五点几的就好，有错误也能在网上找到解决方法，采用最新版的若是出现错误，那么解决起来也麻烦java

而后在加上druid依赖，若是是要用到多数据源，就得用 druid-spring-boot-startermysql

而后在build里设置下配置文件的扫描路径，pom.xml具体依赖以下web

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.liy</groupId>
    <artifactId>mybatisProject</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatisProject</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.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
            <version>5.1.30</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
       <resources>
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.xml</include>
               </includes>
           </resource>
           <resource>
               <directory>src/main/resources</directory>
           </resource>
       </resources>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>`

而后在application.properties配置文件中配置数据源信息（我这里打算用两个数据源）spring

spring.datasource.one.username=root
spring.datasource.one.password=root
spring.datasource.one.url=jdbc:mysql:///again
spring.datasource.one.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.one.driver-class-name=com.mysql.jdbc.Driver


spring.datasource.two.username=root
spring.datasource.two.password=root
spring.datasource.two.url=jdbc:mysql:///demo
spring.datasource.two.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.two.driver-class-name=com.mysql.jdbc.Driver

若是只是一个数据源前缀是spring.datasource.username 这也是默认的扫描前缀sql

由于咱们这里采用两个数据源，因此为了区别两个数据源咱们分别给他们加上了 spring.datasource.**one.**username=root数据库

spring.datasource.**two.**username=rootspringboot

可是咱们把前缀改了，那么spring-boot也就找不到默认的前缀，那么这两个数据源的配置信息也就不会去扫描mybatis

因此咱们得本身去写个配置类，来获取和区别这两个数据源 DatasourceConfig.javaapp

@Configuration
public class DataSourceConfig {

    @Bean
    @ConfigurationProperties("spring.datasource.one")
    DataSource dsOne(){
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties("spring.datasource.two")
    DataSource dsTwo(){
        return DruidDataSourceBuilder.create().build();
    }
}

而后得把数据源分别弄给咱们的mybatis配置类去写两个mybatis配置类，内容基本同样，可是用于区分两个数据源 MybatisConfig1maven

@Configuration
@MapperScan(basePackages = "com.liy.mapper",sqlSessionFactoryRef = "sqlSessionFactoryBean1",
sqlSessionTemplateRef = "sqlSessionTemplate1")
public class MyBatisConfig1 {

    @Resource(name = "dsOne")
    DataSource dsOne;

    @Bean
    SqlSessionFactory sqlSessionFactoryBean1(){
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dsOne);
        SqlSessionFactory factory = null;
        try {
            factory = factoryBean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return factory;
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplate1(){
        return new SqlSessionTemplate(sqlSessionFactoryBean1());
    }

}

MybatisConfig1

@Configuration
@MapperScan(basePackages = "com.liy.mapper2",sqlSessionFactoryRef = "sqlSessionFactoryBean2",
sqlSessionTemplateRef = "sqlSessionTemplate2")
public class MyBatisConfig2 {

    @Resource(name = "dsTwo")
    DataSource dsTwo;

    @Bean
    SqlSessionFactory sqlSessionFactoryBean2(){
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dsTwo);
        SqlSessionFactory factory = null;
        try {
            factory = factoryBean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return factory;
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplate2(){
        return new SqlSessionTemplate(sqlSessionFactoryBean2());
    }

}

而后分别写两个mapper包里对应的接口和映射文件

咱们就只测试一下，那就分别查询下

UserMapper 普通的sql语句也能够直接用注解来，不过不推荐

public interface UserMapper {
    //@Select("select * from user")
    public List<User> selectAll();
}

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.liy.mapper.UserMapper">
    <select id="selectAll" resultType="com.liy.bean.User">
        select * from user
    </select>
</mapper>

另外一个mapper2的代码也就不发了，也是基本和mapper里的同样

只是些路径和数据库查询的表名不太同样

记得写个bean类接收，我找了两个类似的表来查询，全部就只用写一个bean类来接收就行

setter和getter方法就省略了

public class User {
    private int id;
    private String name;
    private int age;
    private String address;

基本都准备好了，那么就开始测试吧

直接在spring-boot工程自带的测试类里测试便可

@RunWith(SpringRunner.class)
@SpringBootTest
public class MybatisApplicationTests {
    @Autowired
    UserMapper um;

    @Autowired
    UserMapper2 um2;
    @Test
    public void contextLoads() {
        List<User> user = um.selectAll();
        System.out.println(user);

        List<User> users = um2.selectAll();
        System.out.println(users);
    }

}

um 和 um2上应该都有红色波浪线，只是springboot未找到仍是啥的，可是仍是注入进来了

两个表的数据也都查询出来了