本例使用mysql作为数据库,使用druid作为数据库连接池
主要有单数据源和多数据源实例;
多数据源中又分为:1. 分包形式 2. aop形式 3. 注解形式
项目目录结构
catalog.pngMyBatis配置实现
springBoot相比于原来的Spring的模式就是减少xml配置,将它们用java代码实现。
- DataSource的bean,主要配置数据来源
- SqlSessionFactoryBean的bean,引用 datasource,MyBatis配置,sql的xml扫描,以及各个插件的添加
- MapperScannerConfigurer的bean的,主要设置基本扫描包,引用SqlSessionFactoryBean
- DataSourceTransactionManager的bean,主要用设置事务
添加maven依赖
<!-- aop -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.4</version>
</dependency>
<!-- dataSource start -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.2.0</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.20</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.0.0</version>
</dependency>
<!-- dataSource end -->
单数据源
基本配置
在application.yml中添加datasource配置:
spring:
application:
name: SpringBoot
datasource:
url: jdbc:mysql://localhost:3306/YanYPro?useUnicode=true&characterEncoding=UTF-8&&useSSL=false
username: root
password: *****
driver-class-name: com.mysql.jdbc.Driver
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
# 初始化大小,最小,最大
initialSize: 5
minIdle: 5
maxActive: 20
# 配置获取连接等待超时的时间
maxWait: 60000
# 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒
timeBetweenEvictionRunsMillis: 60000
# 配置一个连接在池中最小生存的时间,单位是毫秒
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
# 打开PSCache,并且指定每个连接上PSCache的大小
poolPreparedStatements: true
maxPoolPreparedStatementPerConnectionSize: 20
# 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙
filters: stat,wall,log4j
# 通过connectProperties属性来打开mergeSql功能;慢SQL记录
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
# 合并多个DruidDataSource的监控数据
useGlobalDataSourceStat: true
配置mybatis-config:
以下只是实例,可自定义添加一些别的配置
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 全局参数 -->
<settings>
<!-- 使全局的映射器启用或禁用缓存。 -->
<setting name="cacheEnabled" value="true"/>
<!-- 全局启用或禁用延迟加载。当禁用时,所有关联对象都会即时加载。 -->
<setting name="lazyLoadingEnabled" value="true"/>
<!-- 当启用时,有延迟加载属性的对象在被调用时将会完全加载任意属性。否则,每种属性将会按需要加载。 -->
<setting name="aggressiveLazyLoading" value="true"/>
<!-- 是否允许单条sql 返回多个数据集 (取决于驱动的兼容性) default:true -->
<setting name="multipleResultSetsEnabled" value="true"/>
<!-- 是否可以使用列的别名 (取决于驱动的兼容性) default:true -->
<setting name="useColumnLabel" value="true"/>
<!-- 允许JDBC 生成主键。需要驱动器支持。如果设为了true,这个设置将强制使用被生成的主键,有一些驱动器不兼容不过仍然可以执行。 default:false -->
<setting name="useGeneratedKeys" value="true"/>
<!-- 指定 MyBatis 如何自动映射 数据基表的列 NONE:不隐射 PARTIAL:部分 FULL:全部 -->
<setting name="autoMappingBehavior" value="PARTIAL"/>
<!-- 这是默认的执行类型 (SIMPLE: 简单; REUSE: 执行器可能重复使用prepared statements语句;BATCH: 执行器可以重复执行语句和批量更新) -->
<setting name="defaultExecutorType" value="SIMPLE"/>
<!-- 使用驼峰命名法转换字段。 -->
<setting name="mapUnderscoreToCamelCase" value="true"/>
<!-- 设置本地缓存范围 session:就会有数据的共享 statement:语句范围 (这样就不会有数据的共享 ) defalut:session -->
<setting name="localCacheScope" value="SESSION"/>
<!-- 设置但JDBC类型为空时,某些驱动程序 要指定值,default:OTHER,插入空值时不需要指定类型 -->
<setting name="jdbcTypeForNull" value="NULL"/>
</settings>
</configuration>
代码实现
SingleMyBatisConfig的类实现
继承EnvironmentAware并实现setEnvironment,为了获取默认配置文件application.yml的元素。
@Configuration
public class SingleMyBatisConfig implements EnvironmentAware{
private final static Logger logger = LoggerFactory.getLogger(SingleMyBatisConfig.class);
private static String MYBATIS_CONFIG = "mybatis-config.xml";
//mybatis mapper resource 路径
private static String MAPPER_PATH = "classpath:/com/yany/mapper/single/**.xml";
private RelaxedPropertyResolver propertyResolver;
@Override
public void setEnvironment(Environment environment) {
this.propertyResolver = new RelaxedPropertyResolver(environment, "spring.datasource.");
}
.......
}
添加@Bean(name = "singleDataSource"),设置实现DataSource的bean
/**
* @return
* @Primary 优先方案,被注解的实现,优先被注入
*/
@Primary
@Bean(name = "singleDataSource")
public DataSource singleDataSource() {
logger.info("datasource url:{}", propertyResolver.getProperty("url"));
DruidDataSource datasource = new DruidDataSource();
datasource.setUrl(propertyResolver.getProperty("url"));
datasource.setDriverClassName(propertyResolver.getProperty("driver-class-name"));
datasource.setUsername(propertyResolver.getProperty("username"));
datasource.setPassword(propertyResolver.getProperty("password"));
datasource.setInitialSize(Integer.valueOf(propertyResolver.getProperty("initialSize")));
datasource.setMinIdle(Integer.valueOf(propertyResolver.getProperty("minIdle")));
datasource.setMaxWait(Long.valueOf(propertyResolver.getProperty("maxWait")));
datasource.setMaxActive(Integer.valueOf(propertyResolver.getProperty("maxActive")));
datasource.setTimeBetweenEvictionRunsMillis(Long.valueOf(propertyResolver.getProperty("timeBetweenEvictionRunsMillis")));
datasource.setMinEvictableIdleTimeMillis(Long.valueOf(propertyResolver.getProperty("minEvictableIdleTimeMillis")));
datasource.setValidationQuery(propertyResolver.getProperty("validationQuery"));
datasource.setTestWhileIdle(Boolean.parseBoolean(propertyResolver.getProperty("testWhileIdle")));
datasource.setTestOnBorrow(Boolean.parseBoolean(propertyResolver.getProperty("testOnBorrow")));
datasource.setTestOnReturn(Boolean.parseBoolean(propertyResolver.getProperty("testOnReturn")));
datasource.setPoolPreparedStatements(Boolean.parseBoolean(propertyResolver.getProperty("poolPreparedStatements")));
datasource.setMaxPoolPreparedStatementPerConnectionSize(Integer.valueOf(propertyResolver.getProperty("maxPoolPreparedStatementPerConnectionSize")));
try {
datasource.setFilters(propertyResolver.getProperty("filters"));
} catch (SQLException e) {
e.printStackTrace();
}
return datasource;
}
添加@Bean(name = "singleSqlSessionFactory"),设置实现SqlSessionFactoryBean
/**
* 创建sqlSessionFactory实例
*
* @return
*/
@Bean(name = "singleSqlSessionFactory")
@Primary
public SqlSessionFactoryBean createSqlSessionFactoryBean(@Qualifier("singleDataSource") DataSource singleDataSource) throws IOException {
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
//设置mybatis configuration 扫描路径
sqlSessionFactoryBean.setConfigLocation(new ClassPathResource(MYBATIS_CONFIG));
sqlSessionFactoryBean.setDataSource(singleDataSource);
PathMatchingResourcePatternResolver pathMatchingResourcePatternResolver = new PathMatchingResourcePatternResolver();
sqlSessionFactoryBean.setMapperLocations(pathMatchingResourcePatternResolver.getResources(MAPPER_PATH));
return sqlSessionFactoryBean;
}
添加@Bean(name = "singleTransactionManager"),设置实现事务DataSourceTransactionManager
/**
* 配置事务管理器
*/
@Bean(name = "singleTransactionManager")
@Primary
public DataSourceTransactionManager transactionManager(@Qualifier("singleDataSource") DataSource singleDataSource) throws Exception {
return new DataSourceTransactionManager(singleDataSource);
}
以上SingleMyBatisConfig的配置完成,上面主要配置了数据源、SqlSessionFactoryBean、事务(DataSourceTransactionManager)。还差一个MapperScannerConfigurer的配置。
MapperScannerConfig
本来主要集中实现各个数据源的MapperScannerConfigurer
@Configuration
public class MapperScannerConfig {
/**
* 单数据源配置
*
* @return
*/
@Bean
public MapperScannerConfigurer createSingleMapperScannerConfigurer() {
System.out.println("singleDataSource");
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setBasePackage("com.yany.dao.single");
mapperScannerConfigurer.setSqlSessionFactoryBeanName("singleSqlSessionFactory");
return mapperScannerConfigurer;
}
}
以上即为单数据源使用配置,而具体的dao层的编写以及sql的xml编写详情见:https://github.com/yany8060/SpringDemo.git
com.yany.dao.single中编写单属于的到接口
com.yany.mapper.single中编写对应的sql的xml
由于贴了比较多的代码,在下一篇多数据中中将直接类比这篇中的代码
详情请见:https://github.com/yany8060/SpringDemo.git
博客:http://yany8060.xyz
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