SpringBoot整合Mybatis

一、整合

项目包结构如下图所示：

1、pom文件

<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>BootProject</groupId>
  <artifactId>BootProject</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.2.RELEASE</version>
    </parent>
    <!-- 管理版本 -->
    <properties>
        <java.version>1.8</java.version>
        <mybatis.version>3.2.6</mybatis.version> 
        <mysql.version>5.1.38</mysql.version>
        <mybatis.generator.version>1.3.2</mybatis.generator.version>        
    </properties>
    <dependencies>
        <!-- spring -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!-- mybatis -->
            <dependency>  
            <groupId>org.mybatis</groupId>  
            <artifactId>mybatis</artifactId>  
            <version>${mybatis.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>org.mybatis</groupId>  
            <artifactId>mybatis-spring</artifactId>  
            <version>1.2.2</version>  
        </dependency>  
        <!-- mybatis generator --> 
        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>${mybatis.generator.version}</version>
            <scope>compile</scope>
            <optional>true</optional>
        </dependency>
        <!-- Mysql -->  
        <dependency>  
            <groupId>mysql</groupId>  
            <artifactId>mysql-connector-java</artifactId>  
            <version>${mysql.version}</version>  
        </dependency> 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>1.4.0.RELEASE</version>
        </dependency>   
    </dependencies>
  <build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
          <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                 <configuration>
                    <verbose>true</verbose>
                    <overwrite>true</overwrite>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>mysql</groupId>
                        <artifactId>mysql-connector-java</artifactId>
                        <version>${mysql.version}</version>
                    </dependency>
                </dependencies>
            </plugin>
    </plugins>
</build>
</project>

注：这里没有采用通用mapper。

2、generator生成实体和mapper

注：这里采用pdm生成数据库表，根据表逆向工程生成实体和mapper文件。

配置generatorConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>

    <!DOCTYPE generatorConfiguration 
      PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
      "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

    <generatorConfiguration>
    <!-- 配置参数从properties中读取 -->
    <properties resource="generatorConfig.properties" />
    <context id="Mysql" targetRuntime="MyBatis3Simple">
      <commentGenerator>
        <property name="suppressAllComments" value="true"/>
      </commentGenerator>
      <!-- 数据库连接 -->
    <jdbcConnection driverClass="${jdbc.driverClass}"
        connectionURL="${jdbc.url}" userId="${jdbc.user}" password="${jdbc.password}">
    </jdbcConnection>
      <javaTypeResolver>
         <property name="forceBigDecimals" value="false"/>
      </javaTypeResolver>
      <!-- 实体 -->
      <javaModelGenerator targetPackage="com.mybatis.model" targetProject="src/main/java">
          <property name="enableSubPackages" value="true"/>
          <property name="trimStrings" value="true"/>
      </javaModelGenerator>
        <!-- mapper文件 -->      
      <sqlMapGenerator targetPackage="sqlmap" targetProject="src/main/resources">
           <property name="enableSubPackages" value="true"/>
      </sqlMapGenerator>   
      <!-- mapper接口 --> 
      <javaClientGenerator type="XMLMAPPER" targetPackage="com.mybatis.mapper" targetProject="src/main/java">
        <property name="enableSubPackages" value="true"/>
      </javaClientGenerator>
      <!-- tableName表名，domainObjectName实体名 -->
      <table  tableName="t_User" domainObjectName="User" enableCountByExample="false" enableSelectByExample="false" enableUpdateByExample="false" enableDeleteByExample="false">

      </table>
    </context>

    </generatorConfiguration>

generatorConfig.properties

jdbc.driverClass = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
jdbc.user = root
jdbc.password = root
mapper.plugin = tk.mybatis.mapper.generator.MapperPlugin
mapper.Mapper = tk.mybatis.mapper.common.Mapper

执行maven命令：mybatis-generator:generate，刷新项目即可。

3、注入mapper接口代理

/** 
 * @author  saixing_yang@hiersun.com
 * @date 创建时间：2016年12月21日 下午4:35:59 
 * @version 1.0 
 */
@Configuration  //刷新配置信息 boot会自动注入datasource，但mapper的路径需要手动注入
@EnableTransactionManagement // 启注解事务管理，等同于xml配置方式的 <tx:annotation-driven />
public class MybatisConfig implements TransactionManagementConfigurer {
    @Autowired
    private DataSource dataSource;

    @Bean(name = "sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean bean =new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().
                getResources("classpath:com/common/dao/mapper/UserMapper.xml"));    
        return bean.getObject();
    }
    @Bean
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Override
    public PlatformTransactionManager annotationDrivenTransactionManager() {
        return new DataSourceTransactionManager(dataSource);
    }
}

MybatisMapperScannerConfig 自动扫描配置

@Configuration
public class MybatisMapperScannerConfig {
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer scanner = new MapperScannerConfigurer();
        scanner.setSqlSessionFactoryBeanName("sqlSessionFactory");  //set 手动配置的sqlSessionFactory
        scanner.setBasePackage("com.common.dao");
        return scanner;
    }
}

二、常见问题

SpringBoot扫描包问题

报错信息：Consider defining a bean of type in your configuration

方法一：

使用注解 @ComponentScan(value=”com.common”)，其中，com.common为包路径。

方法二：
将启动类Application放在上一级包中。
如下图所示：

三、总结

SpringBoot使得开发效率大大提升，我们不再需要写一堆繁琐的配置文件来说明类与类的关系。取而代之的是，我们只需要关心如何让一个Bean可以被springboot扫描到就好了。

嘿嘿，这感觉好像你之前要自己去超市购物，然后带回家。现在有人帮你买了拿回来，但你需要把你家的地址告诉他，然后你就可以省出很多时间做其他的事情了。