Java实现多数据源的方式
一、利用Spring提供的类实现
1)在yml文件当中配置多数据源
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
datasource1:
url: jdbc:mysql://127.0.0.1:3306/datasource1?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
username: root
password: root
initial-size: 1
min-idle: 1
max-active: 20
test-on-borrow: true
driver-class-name: com.mysql.cj.jdbc.Driver
datasource2:
url: jdbc:mysql://127.0.0.1:3306/datasource2?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
username: root
password: root
initial-size: 1
min-idle: 1
max-active: 20
test-on-borrow: true
driver-class-name: com.mysql.cj.jdbc.Driver
2) 定义一个DataSourceConfig 配置类来配置两个数据源
@Configuration
public class DataSourceConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.datasource1")
public DataSource dataSource1() {
// 底层会自动拿到spring.datasource中的配置, 创建一个DruidDataSource
return DruidDataSourceBuilder.create().build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.datasource2")
public DataSource dataSource2() {
// 底层会自动拿到spring.datasource中的配置, 创建一个DruidDataSource
return DruidDataSourceBuilder.create().build();
}
/* @Bean
public Interceptor dynamicDataSourcePlugin(){
return new DynamicDataSourcePlugin();
}
*/
@Bean
public DataSourceTransactionManager transactionManager1(DynamicDataSource dataSource){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
dataSourceTransactionManager.setDataSource(dataSource);
return dataSourceTransactionManager;
}
@Bean
public DataSourceTransactionManager transactionManager2(DynamicDataSource dataSource){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
dataSourceTransactionManager.setDataSource(dataSource);
return dataSourceTransactionManager;
}
}
3)自定义一个类 来 继承 org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
** 在类里面注入分别注入两个数据源**文章来源:https://www.toymoban.com/news/detail-549937.html
@Component
@Primary // 将该Bean设置为主要注入Bean
public class DynamicDataSource extends AbstractRoutingDataSource {
// 当前使用的数据源标识
public static ThreadLocal<String> name=new ThreadLocal<>();
// 写
@Autowired
DataSource dataSource1;
// 读
@Autowired
DataSource dataSource2;
// 返回当前数据源标识
@Override
protected Object determineCurrentLookupKey() {
return name.get();
}
}
// ** 在这个类初始化完成之后,进行数据源的注入**
// 当前使用的数据源标识
public static ThreadLocal<String> name=new ThreadLocal<>();
@Override
public void afterPropertiesSet() {
// 为targetDataSources初始化所有数据源
Map<Object, Object> targetDataSources=new HashMap<>();
targetDataSources.put("W",dataSource1);
targetDataSources.put("R",dataSource2);
super.setTargetDataSources(targetDataSources);
// 为defaultTargetDataSource 设置默认的数据源
super.setDefaultTargetDataSource(dataSource1);
super.afterPropertiesSet();
}
4) 添加一个根据注解设置的动态数据源
@Component
@Aspect
public class DynamicDataSourceAspect implements Ordered {
// 前置
@Before("within(com.tuling.dynamic.datasource.service.impl.*) && @annotation(wr)")
public void before(JoinPoint point, WR wr){
String name = wr.value();
DynamicDataSource.name.set(name);
System.out.println(name);
}
@Override
public int getOrder() {
return 0;
}
// 环绕通知
}
5) 在service中使用指定的数据源
@Service
public class FriendImplService implements FriendService {
@Autowired
FriendMapper friendMapper;
@Override
@WR("R") // 库2
public List<Friend> list() {
// DynamicDataSource.name.set("R");
return friendMapper.list();
}
@Override
@WR("W") // 库1
public void save(Friend friend) {
// DynamicDataSource.name.set("W");
friendMapper.save(friend);
}
}
上面采用注解的方式就是,其实是利用切面进行数据源的设置,和注释的注释方式类似文章来源地址https://www.toymoban.com/news/detail-549937.html
二、利用mybatis层次实现
1)分别配置两个配置源,单独配置
2) 编写WMyBatisConfig配置文件
@Configuration
// 继承mybatis:
// 1. 指定扫描的mapper接口包(主库)
// 2. 指定使用sqlSessionFactory是哪个(主库)
@MapperScan(basePackages = "com.datasource.dynamic.mybatis.mapper.w",
sqlSessionFactoryRef="wSqlSessionFactory")
public class WMyBatisConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.datasource1")
public DataSource dataSource1() {
// 底层会自动拿到spring.datasource中的配置, 创建一个DruidDataSource
return DruidDataSourceBuilder.create().build();
}
@Bean
@Primary
public SqlSessionFactory wSqlSessionFactory()
throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
// 指定主库
sessionFactory.setDataSource(dataSource1());
// 指定主库对应的mapper.xml文件
/*sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
.getResources("classpath:mapper/order/*.xml"));*/
return sessionFactory.getObject();
}
@Bean
@Primary
public DataSourceTransactionManager wTransactionManager(){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
dataSourceTransactionManager.setDataSource(dataSource1());
return dataSourceTransactionManager;
}
@Bean
public TransactionTemplate wTransactionTemplate(){
return new TransactionTemplate(wTransactionManager());
}
}
3) 编写RMyBatisConfig 配置文件
@Configuration
// 继承mybatis:
// 1. 指定扫描的mapper接口包(主库)
// 2. 指定使用sqlSessionFactory是哪个(主库)
@MapperScan(basePackages = "com.tuling.datasource.dynamic.mybatis.mapper.r",
sqlSessionFactoryRef="rSqlSessionFactory")
public class RMyBatisConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.datasource2")
public DataSource dataSource2() {
// 底层会自动拿到spring.datasource中的配置, 创建一个DruidDataSource
return DruidDataSourceBuilder.create().build();
}
@Bean
@Primary
public SqlSessionFactory rSqlSessionFactory()
throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
// 指定主库
sessionFactory.setDataSource(dataSource2());
// 指定主库对应的mapper.xml文件
/*sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
.getResources("classpath:mapper/r/*.xml"));*/
return sessionFactory.getObject();
}
@Bean
public DataSourceTransactionManager rTransactionManager(){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
dataSourceTransactionManager.setDataSource(dataSource2());
return dataSourceTransactionManager;
}
@Bean
public TransactionTemplate rTransactionTemplate(){
return new TransactionTemplate(rTransactionManager());
}
}
4) 在serviceImpl实现层 单独调用配置的Mapper代理类
@Autowired
private RFriendMapper rFriendMapper;
@Autowired
private WFriendMapper wFriendMapper;
// 读-- 读库
@Override
public List<Friend> list() {
return rFriendMapper.list();
}
// 保存-- 写库
@Override
public void saveW(Friend friend) {
friend.setName("loulan");
wFriendMapper.save(friend);
}
// 保存-- 读库
@Override
public void saveR(Friend friend) {
friend.setName("loulan");
rFriendMapper.save(friend);
}
三、Spring自动化支持
1) 引入pom依赖
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
<version>3.5.0</version>
</dependency>
2) 添加配置文件
spring:
datasource:
dynamic:
#设置默认的数据源或者数据源组,默认值即为master
primary: master
#严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
strict: false
datasource:
master:
url: jdbc:mysql://127.0.0.1:3306/datasource1?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
username: root
password: root
initial-size: 1
min-idle: 1
max-active: 20
test-on-borrow: true
driver-class-name: com.mysql.cj.jdbc.Driver
slave_1:
url: jdbc:mysql://127.0.0.1:3306/datasource2?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
username: root
password: root
initial-size: 1
min-idle: 1
max-active: 20
test-on-borrow: true
driver-class-name: com.mysql.cj.jdbc.Driver
3)在service层利用注解==@DS实现==
@Service
public class FriendImplService implements FriendService {
@Autowired
FriendMapper friendMapper;
@Override
@DS("slave_1") // 从库, 如果按照下划线命名方式配置多个 , 可以指定前缀即可(组名)
public List<Friend> list() {
return friendMapper.list();
}
@Override
@DS("master")
public void save(Friend friend) {
friendMapper.save(friend);
}
@DS("master")
@DSTransactional
public void saveAll(){
// 执行多数据源的操作
}
}
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