Environment: intellij15 , jdk1.8 , maven3
Reference: http://www.jb51.net/article/104053.htm
1. Generate ssm project, see http://liguanshi.iteye.com/blog/2413023
2. Add a database connection in the jdbc.properties file
#============================================================================ # postgresql #============================================================================ jdbc.postgresql.driver = org.postgresql.Driver jdbc.postgresql.url = jdbc:postgresql://127.0.0.1:5432/cz?characterEncoding=UTF-8 jdbc.postgresql.username = postgres jdbc.postgresql.password = ****** #============================================================================ # oracle #============================================================================ jdbc.oracle.driver=oracle.jdbc.driver.OracleDriver jdbc.oracle.url=jdbc:oracle:thin:@smart-dafeng:1521:orcl jdbc.oracle.username=df jdbc.oracle.password=******
3. Add database connection and multipleDataSource beans in applicationContext - dao.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--Get database configuration file-->
<context:property-placeholder location="classpath:config/jdbc.properties"/>
<!--Set data source c3p0-->
<bean id="oracleDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="${jdbc.oracle.driver}"/>
<property name="jdbcUrl" value="${jdbc.oracle.url}"/>
<property name="user" value="${jdbc.oracle.username}"/>
<property name="password" value="${jdbc.oracle.password}"/>
<property name="maxPoolSize" value="50"/>
<property name="minPoolSize" value="2"/>
<property name="maxIdleTime" value="60"/>
</bean>
<!--Set data source c3p0-->
<bean id="postgresqlDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="${jdbc.postgresql.driver}"/>
<property name="jdbcUrl" value="${jdbc.postgresql.url}"/>
<property name="user" value="${jdbc.postgresql.username}"/>
<property name="password" value="${jdbc.postgresql.password}"/>
<property name="maxPoolSize" value="50"/>
<property name="minPoolSize" value="2"/>
<property name="maxIdleTime" value="60"/>
</bean>
<bean id="multipleDataSource" class="com.elin4it.ssm.utils.MultipleDataSource">
<property name="defaultTargetDataSource" ref="postgresqlDataSource"/>
<property name="targetDataSources">
<map>
<entry key="postgresqlDataSource" value-ref="postgresqlDataSource"/>
<entry key="oracleDataSource" value-ref="oracleDataSource"/>
</map>
</property>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="multipleDataSource"/>
</bean>
<!-- mybatis.spring auto-mapping -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.elin4it.ssm.mapper"/>
</bean>
<!-- Automatic scanning, multiple packages separated by commas -->
<context:component-scan base-package="com.elin4it.ssm"/>
<aop:aspectj-autoproxy/>
</beans>
4. Add the MultipleDataSource class to com.elin4it.ssm.utils
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
* Created by Administrator on 2018/3/21.
*/
public class MultipleDataSource extends AbstractRoutingDataSource {
private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<String>();
public static void setDataSourceKey(String dataSource) {
dataSourceKey.set(dataSource);
}
@Override
protected Object determineCurrentLookupKey() {
return dataSourceKey.get();
}
}
5. Comment out the content of applicationContext-transaction.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--<bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">-->
<!--<property name="dataSource" ref="dataSource"/>-->
<!--</bean>-->
<!--<tx:advice id="txAdvice" transaction-manager="dataSourceTransactionManager">-->
<!--<tx:attributes>-->
<!--<tx:method name="find*" propagation="REQUIRED"/>-->
<!--<tx:method name="update*" propagation="REQUIRED"/>-->
<!--<tx:method name="delete*" propagation="REQUIRED"/>-->
<!--<tx:method name="add*" propagation="REQUIRED"/>-->
<!--</tx:attributes>-->
<!--</tx:advice>-->
<!--<aop:config>-->
<!--<aop:advisor advice-ref="txAdvice" pointcut="execution(* cn.elinzhou.ixxs.service.*.*(..))"/>-->
<!--</aop:config>-->
</beans>
6. Add a database selection statement in UserServiceImpl : MultipleDataSource.setDataSourceKey("oracleDataSource");
The completion code looks like this:
package com.elin4it.ssm.service;
import com.elin4it.ssm.mapper.StudentsMapper;
import com.elin4it.ssm.pojo.Students;
import com.elin4it.ssm.utils.MultipleDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* Created by Administrator on 2018/3/21.
*/
@Service
public class UserServiceImpl implements UserService {
//User interface needs to add <span style="font-family: Arial, Helvetica, sans-serif;">@Component to dependency injection on UserMapper interface when injecting UserMapper here</span>
@Autowired
private StudentsMapper userMapper;
public Students findUser() throws Exception {
// Switch the database here and output different results
// MultipleDataSource.setDataSourceKey("postgresqlDataSource");
MultipleDataSource.setDataSourceKey("oracleDataSource");
//Call the selectByExample method in the mapper class, if the incoming type is null, it means unconditional search
Students users = userMapper.selectByPrimaryKey(2);
return users;
}
}
7. Add oracle database dependency in pom :
<!-- database driver-->
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc6</artifactId>
<version>11.2.0.1.0</version>
</dependency>
8. Run. Oracle database output:
After modifying the UserServiceImpl.java code, the Postgresql database outputs the result:
