Usage instance resolution of Spring MVC Mybatis multiple data sources

The project needs to obtain data from other websites, because it is a temporary requirement, I did not expect to need multiple data sources when I started the project

So baidu 1, found that only need to change 1 Spring applicationContext.xml file and write three tool classes can be perfectly realized

applicationContext.xml

<!--  Multi-data source configuration  -->
 <bean id="ds1" class="org.apache.commons.dbcp.BasicDataSource">
  <property name="driverClassName" value="${jdbc.driverClassName}" />
  <property name="url" value="${jdbc.url}" />
  <property name="username" value="${jdbc.username}" />
  <property name="password" value="" />
 </bean>
 <bean id="ds2" class="org.apache.commons.dbcp.BasicDataSource">
  <property name="driverClassName" value="" />
  <property name="url" value="" />
  <property name="username" value="" />
  <property name="password" value="" />
 </bean>
 <!--  Dynamic configuration data source  -->
 <bean id="dataSource" class="com.test.utils.DynamicDataSource">// This is your project DynamicDataSource.java The path of the 
  <property name="targetDataSources">
   <map key-type="java.lang.String">
    <entry value-ref="ds_admin" key="ds1"></entry>
    <entry value-ref="ds_partner" key="ds2"></entry>
   </map>
  </property>
  <!--  Use the default ds1 The data source  -->
  <property name="defaultTargetDataSource" ref="ds_admin"></property>  
 </bean>

DataSourceContextHolder.java

public class DataSourceContextHolder {
 private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
 public static void setDbType(String dbType) {
  contextHolder.set(dbType);
 }
 public static String getDbType() {
  return ((String) contextHolder.get());
 }
 public static void clearDbType() {
  contextHolder.remove();
 }
}

DataSourceType.java (set static variable)

public class DataSourceType {
 //  Default database 
 public static final String SOURCE_ADMIN = "ds1";
 //  The first 2 Database, in applicationContext.xml In the id
 public static final String SOURCE_PARTNER = "ds2";
}

Next is the key: DynamicDataSource.java, which inherits the abstract method determineCurrentLookupKey from AbstractRoutingDataSource, which is the core of route implementing the data source.

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
 @Override
 protected Object determineCurrentLookupKey() {
  return DataSourceContextHolder.getDbType();
 }
}