SpringBoot2+Mybatis的多数据源配置实现
SpringBoot2+Mybatis的多数据源配置实现
- 概述
- Multi-DataSource 模块的建立
-
- 定义TargetDataSource注解
- 定义Aop拦截器
- 定义多线程下data source type的存取器
- 定义数据源注册器
- 定义自定义数据源
- 定义EnableMultiDataSource
- 在yml里面配置多数据源参数
- 启动类必须加上注解
- 测试
- 不用Aop拦截的处理方式
概述
多数据源的实现有不同的方法, 有的是通过配置不同的datasource,不同的SqlSessionFactory,每个SqlSessionFactory管理不同位置的mapper这种方式;也有的用同一套mapper, 动态切换不同的数据源, 而因为实现需要, 我这里要实现的是第二种方式.
Multi-DataSource 模块的建立
在原有的maven项目里面,加入这个新的multi-datasource模块
定义TargetDataSource注解
此注解用于标识当前方法用的是哪个数据源, 用于aop的filter
/**
*
* Created by rocklee on 2020/8/27 10:44
*/
@Target({
java.lang.annotation.ElementType.METHOD, java.lang.annotation.ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource {
String value();
}
定义Aop拦截器
/**
* Created by rocklee on 2020/8/27 10:07
*/
@Aspect
@Order(0)
@Component
public class DataSourceAspect {
private Logger logger = LoggerFactory.getLogger(DataSourceAspect.class);
@Before("@annotation(targetDataSource)")
public void changeDataSource(JoinPoint point, TargetDataSource targetDataSource) throws Throwable {
String dsId = targetDataSource.value();
if (!DataSourceContextHolder.containsDataSource(dsId)) {
logger.info("数据源(" + dsId + ")不存在-" + point.getSignature());
} else {
logger.info("使用数据源(" + dsId + ")-" + point.getSignature());
DataSourceContextHolder.setDataSourceType(targetDataSource.value());
}
}
@After("@annotation(targetDataSource)")
public void restoreDataSource(JoinPoint point, TargetDataSource targetDataSource) {
logger.info("恢复数据源-" + point.getSignature());
DataSourceContextHolder.clearDataSourceType();
}
}
此拦截器或选,后面有讲
定义多线程下data source type的存取器
/**
* 支持多线程环境下的data source type的存取
* Created by rocklee on 2020/8/27 10:00
*/
public class DataSourceContextHolder {
private static final ThreadLocal<String> contextHolder = new ThreadLocal();
private static final List<String> dataSourceIds = new ArrayList();
public static void setDataSourceType(String dataSourceType) {
contextHolder.set(dataSourceType);
}
public static String getDataSourceType() {
return (String) contextHolder.get();
}
public static void clearDataSourceType() {
contextHolder.remove();
}
public static boolean containsDataSource(String dataSourceId) {
return dataSourceIds.contains(dataSourceId);
}
public static List<String> getDataSourceIds() {
return dataSourceIds;
}
}
定义数据源注册器
注册器分别从yml配置里面获得默认的datasource和其他datasource,后面的yml参数显示, 各datasource的数据库均可自定义, 也就是说可以让boot同时使用postgresql/mysql/oracle等数据库.
/**
* Created by rocklee on 2020/8/27 10:46
*/
public class DataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware {
private Logger logger = LoggerFactory.getLogger("DynamicDataSource");
private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource";
private ConversionService conversionService = new DefaultConversionService();
//private static Map sourcePoolMap = new HashMap();
private static DataSource defaultDataSource;
private static Map<String, DataSource> customdatasources = new HashMap();
private GlobalConfig config;
public static DataSource getDefaultDataSource() {
return defaultDataSource;
}
public static DataSource getCustomDataSource(String dataSourceId){
if (dataSourceId==null||dataSourceId.isEmpty()) return defaultDataSource;
return customdatasources.get(dataSourceId);
}
public void setEnvironment(Environment environment) {
logger.debug("DynamicDataSourceRegister.setEnvironment()");
config= new GlobalConfig(environment);
initDefaultDataSource(environment);
initCustomdatasources(environment);
}
private void initDefaultDataSource(Environment env) {
if (!config.containsProperty("spring.default-datasource")){
logger.error(String.format("Missing config '%s'","spring.default-datasource"));
return;
}
String defaultDataSourceName=config.getValue("spring.default-datasource");
Map<String,Object> paramMap=config.getProperties("spring.datasources."+defaultDataSourceName,true);
if (paramMap.size()==0){
logger.error(String.format("Missing config '%s'","spring.datasources."+defaultDataSourceName));
return;
}
Map<String, Object> dsMap = new HashMap();
dsMap.put("type", paramMap.get("type"));
dsMap.put("driverClassName", paramMap.get("driver-class-name"));
dsMap.put("url", paramMap.get("url"));
dsMap.put("username", paramMap.get("username"));
dsMap.put("password", paramMap.get("password"));
paramMap=config.getProperties("spring.datasources."+defaultDataSourceName+".druid",true);
dsMap.putAll(paramMap);
defaultDataSource = buildDataSource(dsMap);
//dataBinder(defaultDataSource, env);
}
private void initCustomdatasources(Environment env) {
String defaultSource=config.getValue("spring.default-datasource");
List<String> dsSessions = config.getSessions("spring.datasources",true);
for (String dsSession : dsSessions) {
if (dsSession.equals(defaultSource)){
customdatasources.put(dsSession, defaultDataSource);
continue;
}
Map<String,Object> paramMap=config.getProperties("spring.datasources."+dsSession,true);
Map<String, Object> dsMap = new HashMap();
dsMap.put("type", paramMap.get("type"));
dsMap.put("driverClassName", paramMap.get("driver-class-name"));
dsMap.put("url", paramMap.get("url"));
dsMap.put("username", paramMap.get("username"));
dsMap.put("password", paramMap.get("password"));
paramMap=config.getProperties("spring.datasources."+dsSession+".druid",true);
dsMap.putAll(paramMap);
DataSource ds = buildDataSource(dsMap);
customdatasources.put(dsSession, ds);
//dataBinder(ds, env);
}
}
public DataSource buildDataSource(Map<String, Object> dsMap) {
Object type = dsMap.get("type");
if (type == null) {
type = DATASOURCE_TYPE_DEFAULT;
}
try {
Class<? extends DataSource> dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
String driverClassName = dsMap.get("driverClassName").toString();
String url = dsMap.get("url").toString();
String username = dsMap.get("username").toString();
String password = dsMap.get("password").toString();
DruidDataSource dataSource = new DruidDataSource();
dataSource.setUrl(url);
dataSource.setUsername(username);
dataSource.setPassword(password);
dataSource.setDriverClassName(driverClassName);
int initialSize = (Integer)dsMap.get("initialSize");
int minIdle = (Integer)dsMap.get("minIdle");
int maxActive = (Integer) dsMap.get("maxActive");
int maxWait =(Integer) dsMap.get("maxWait");
int timeBetweenEvictionRunsMillis = (Integer) dsMap.get("timeBetweenEvictionRunsMillis");
int minEvictableIdleTimeMillis = (Integer) dsMap.get("minEvictableIdleTimeMillis");
String validationQuery = (String) dsMap.get("validationQuery");
boolean testWhileIdle = (Boolean) dsMap.getOrDefault("testWhileIdle",true);
boolean testOnBorrow = (Boolean) dsMap.getOrDefault("testOnBorrow",false);
boolean testOnReturn =(Boolean) dsMap.getOrDefault("testOnReturn",true);
boolean poolPreparedStatements = (boolean)dsMap.getOrDefault("poolPreparedStatements",true);
int maxPoolPreparedStatementPerConnectionSize = (Integer) dsMap.getOrDefault("maxPoolPreparedStatementPerConnectionSize",20);
String filters = (String) dsMap.get("filters");
String connectionProperties = (String) dsMap.get("connectionProperties");
boolean useGlobaldatasourcestat = (boolean) dsMap.getOrDefault("useGlobaldatasourcestat",true);
dataSource.setInitialSize(initialSize);
dataSource.setMinIdle(minIdle);
dataSource.setMaxActive(maxActive);
dataSource.setMaxWait(maxWait);
dataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
dataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
dataSource.setValidationQuery(validationQuery);
dataSource.setTestWhileIdle(testWhileIdle);
dataSource.setTestOnBorrow(testOnBorrow);
dataSource.setTestOnReturn(testOnReturn);
dataSource.setPoolPreparedStatements(poolPreparedStatements);
dataSource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
dataSource.setFilters(filters);
Properties properties = new Properties();
for (String item : connectionProperties.split(";")) {
String[] attr = item.split("=");
properties.put(attr[0].trim(), attr[1].trim());
}
dataSource.setConnectProperties(properties);
dataSource.setUseGlobalDataSourceStat(useGlobaldatasourcestat);
return dataSource;
} catch (RuntimeException e) {
logger.error("初始化数据源出错!");
e.printStackTrace();
} catch (Exception e) {
logger.error("初始化数据源出错!");
e.printStackTrace();
}
return null;
}
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
logger.debug("DynamicDataSourceRegister.registerBeanDefinitions()");
Map<Object, Object> targetdatasources = new HashMap();
targetdatasources.put("dataSource", defaultDataSource);
DataSourceContextHolder.getDataSourceIds().add("dataSource");
targetdatasources.putAll(customdatasources);
for (String key : customdatasources.keySet()) {
DataSourceContextHolder.getDataSourceIds().add(key);
}
GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
beanDefinition.setBeanClass(MultiDataSource.class);
beanDefinition.setSynthetic(true);
MutablePropertyValues mpv = beanDefinition.getPropertyValues();
/*myRoutingDataSource.setDefaultTargetDataSource(masterDataSource);
myRoutingDataSource.setTargetDataSources(targetDataSources);*/
mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
mpv.addPropertyValue("targetDataSources", targetdatasources);
registry.registerBeanDefinition("dataSource", beanDefinition);
}
}
定义自定义数据源
/**
* Created by rocklee on 2020/8/27 9:59
*/
public class MultiDataSource extends AbstractRoutingDataSource {
public Object determineCurrentLookupKey() {
return DataSourceContextHolder.getDataSourceType();
}
}
定义EnableMultiDataSource
这个注解放在启动类(xxxApplication.java)
/**
* Created by rocklee on 2020/8/27 15:40
*/
@Target({
java.lang.annotation.ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Import({
DataSourceRegister.class})
public @interface EnableMultiDataSource {
}
在yml里面配置多数据源参数
```yaml
default-datasource: db1
datasources:
db1:
driver-class-name: org.postgresql.Driver
url: jdbc:postgresql://host1:5432/db1
username: postgres
password: 123456
type: com.alibaba.druid.pool.DruidDataSource
# 数据源其他配置
druid:
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1
testWhileIdle: true
testOnBorrow: false
testOnReturn: true
poolPreparedStatements: true
# 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
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=200
db2:
driver-class-name: org.postgresql.Driver
url: jdbc:postgresql://host2:5432/db2
username: postgres
password: 123456
type: com.alibaba.druid.pool.DruidDataSource
# 数据源其他配置
druid:
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
# 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
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=200
启动类必须加上注解
@EnableMultiDataSource不能少
如果想用注解+Aop拦截的方式来切换数据源那么一定要加上@EnableAspectJAutoProxy(proxyTargetClass=true,exposeProxy = true)
测试
不用Aop拦截的处理方式
上面显示的都是通过Aop拦截做了targetDataSource注解的方法,在执行此方法之前就切换数据源的方式来实现动态切换数据源, 但是这里有个问题,如果同一个方法需要用到不同的数据源就没法了, 这时候应该需要手动指定数据源.
若手动指定数据源的话, Aop的类可以不要,也不需要在启动项加@EnableAspectJAutoProxy(proxyTargetClass=true,exposeProxy = true) , 也不需要在方法加@TargetDataSource注解,
只需要在mapper操作前加上:
DataSourceContextHolder.setDataSourceType(“db1”); //手动切换数据源
即可.