<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<!--aop依赖 项目中使用了aop，实现数据源的自动切换-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
</dependency>
server:
port: 8087
servlet:
context-path: / #项目路径
spring:
datasource:
main:
username: root
password: jiajia123
url: jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
secondary:
username: root
password: jiajia123
url: jdbc:mysql://localhost:3306/db2?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
mybatis:
mapper-locations: classpath:com/oauth/server/mapper/*Mapper.xml
type-aliases-package: com.oauth.server.entity
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #sql日志打印
call-setters-on-nulls: true #解决返回类型为Map的时候如果值为null将不会封装此字段
在启动类中修改@SpringBootApplication这个配置为：
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
意思要去掉springboot默认的数据源配置，使用自己定义的数据源配置。
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
*
* @author 硅谷探秘者(jia)
*
*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface DS {
String value() default "main";
}
这个注解是用在service层方法上的，从配置文件中可以看出，配置了两个数据源，主数据源main和辅数据源secondary，如果service方法想访问main这个数据源，则不需要任何配置它默认会访问main数据源，或在方法上加个@DS("main")注解，如果想访问辅数据源secondary则需要在方法上加上@DS("secondary")注解。
例子：
//访问主数据源
public void test() {
// TODO Auto-generated method stub
testMapper.test();
}
//访问辅数据源
@DS("secondary")
public void test2() {
// TODO Auto-generated method stub
testMapperDb2.test();
}
注意这个注解一定是要在运行是可以访问到的，所以要加上@Retention(RetentionPolicy.RUNTIME)这个元注解。
/**
* @author 硅谷探秘者(jia)
*/
public class DataSourceContextHolder {
/**
* 默认数据源
*/
public static final String DEFAULT_DS = "main";
private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
// 设置数据源名
public static void setDB(String dbType) {
contextHolder.set(dbType);
}
// 获取数据源名
public static String getDB() {
return (contextHolder.get());
}
// 清除数据源名
public static void clearDB() {
contextHolder.remove();
}
}
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
* @author 硅谷探秘者(jia)
*/
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DataSourceContextHolder.getDB();
}
}
package com.oauth.server.conf;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
* @author 硅谷探秘者(jia)
*/
@Configuration
public class DataSourceConfig {
/**
* 主数据源配置
* @return
*/
@Bean(name = "main")
@ConfigurationProperties(prefix = "spring.datasource.main")
public DataSource main() {
return DataSourceBuilder.create().build();
}
/**
* 辅数据源配置
* @return
*/
@Bean(name = "secondary")
@ConfigurationProperties(prefix = "spring.datasource.secondary")
public DataSource secondary() {
return DataSourceBuilder.create().build();
}
/**
* 动态数据源: 通过AOP在不同数据源之间动态切换
*
* @return
*/
@Primary
@Bean(name = "dynamicDS1")
public DataSource dataSource() {
DynamicDataSource dynamicDataSource = new DynamicDataSource();
// 默认数据源
dynamicDataSource.setDefaultTargetDataSource(main());
// 配置多数据源
Map<Object, Object> dsMap = new HashMap<Object, Object>(5);
dsMap.put("main", main());
dsMap.put("secondary", secondary());
dynamicDataSource.setTargetDataSources(dsMap);
return dynamicDataSource;
}
/**
* 配置@Transactional注解事物
* @return
*/
@Bean
public PlatformTransactionManager transactionManager() {
return new DataSourceTransactionManager(dataSource());
}
}
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;
import java.lang.reflect.Method;
/**
* @author 硅谷探秘者(jia)
*/
@Aspect
@Component
public class DynamicDataSourceAspect {
@Before("@annotation(DS)")
public void beforeSwitchDS(JoinPoint point){
//获得当前访问的class
Class<?> className = point.getTarget().getClass();
//获得访问的方法名
String methodName = point.getSignature().getName();
//得到方法的参数的类型
Class<?>[] argClass = ((MethodSignature)point.getSignature()).getParameterTypes();
String dataSource = DataSourceContextHolder.DEFAULT_DS;
try {
// 得到访问的方法对象
Method method = className.getMethod(methodName, argClass);
System.out.println(method.getName());
System.out.println(method.isAnnotationPresent(DS.class));
// 判断是否存在@DS注解
if (method.isAnnotationPresent(DS.class)) {
DS annotation = method.getAnnotation(DS.class);
// 取出注解中的数据源名
dataSource = annotation.value();
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(dataSource);
// 切换数据源
DataSourceContextHolder.setDB(dataSource);
}
@After("@annotation(DS)")
public void afterSwitchDS(JoinPoint point){
DataSourceContextHolder.clearDB();
}
}
这样配置基本完成，使用的时候只需要在方法上添加@DS注解，标明你要访问的数据源即可。
server层例子
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.oauth.server.conf.DS;
import com.oauth.server.mapper.TestMapper;
import com.oauth.server.mapper.TestMapperDb2;
@Service
public class TestService {
@Autowired
private TestMapper testMapper;
@Autowired
private TestMapperDb2 testMapperDb2;
public void test() {
// TODO Auto-generated method stub
testMapper.test();
}
@DS("secondary")
public void test2() {
// TODO Auto-generated method stub
testMapperDb2.test();
}
}