Abstractroutingdatasource dynamically switching data sources

spring2.0 later added abstractroutingdatasource this thing provides a dynamic switching data source.

Abstractroutingdatasource inherits the Abstractdatasource,abstractdatasource is a subclass of Javax.sql.DataSource.

Here is an example of a dynamically switching data source:

1. configuration file configuration in Spring.xml

<!--Configure connection pooling--
<bean id= "Readandwritedatasouce" class= "Com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method= "Close" >
<property name= "Driverclass" value= "${driver}"/> <!--Specify the drive to connect to the database
<property name= "Jdbcurl" value= "${url}"/> <!--Specify the URL of the connection database--
<property name= "user" value= "${user}"/> <!--Specify the user name to connect to the database--
<property name= "Password" value= "${password}"/> <!--Specify the password to connect to the database--
<property name= "Maxpoolsize" value= "$"/> <!--Specify the maximum number of connections to connect to the database connection pool--
<property name= "Minpoolsize" value= "three"/> <!--Specify the minimum number of connections to connect to the database connection pool (can be larger when production is used)-
<property name= "Initialpoolsize" value= "three"/> <!--Specifies the number of initial connections to connect to the database connection pool (can be changed when production is used)-
<property name= "maxidletime" value= "/> <!--Specify the maximum idle time for connections connecting to a database connection pool-
<!--when the connection pool connection is exhausted, the client calls getconnection () to wait for a new connection, and then throws SqlException after the timeout, and waits indefinitely if set to 0. Unit milliseconds. Default: 0--
<property name= "checkouttimeout" value= "/>"
<property name= "acquireincrement" value= "/> <!--when the connection in the connection pool is exhausted c3p0 the number of connections that are fetched at the same time. Default:3--
<property name= "Acquireretrydelay" value= "three"/><!--two connections in the interval, per millisecond. default:1000--
<property name= "idleconnectiontestperiod" value= "/> <!--check idle connections in all connection pools every 60 seconds. Default:0--
</bean>

<bean id= "Readdatasource" class= "Com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method= "Close" >
<property name= "Driverclass" value= "${driver}"/>
<property name= "Jdbcurl" value= "${urlforread}"/>
<property name= "user" value= "${userforread}"/>
<property name= "Password" value= "${passwordforread}"/>
<property name= "maxpoolsize" value= "/>"
<property name= "minpoolsize" value= "/>"
<property name= "initialpoolsize" value= "/>"
<property name= "maxidletime" value= "/>"
<property name= "checkouttimeout" value= "/>"
<property name= "Acquireincrement" value= "ten"/>
<property name= "Acquireretrydelay" value= "/>"
<property name= "idleconnectiontestperiod" value= "/>"
</bean>
<!--Multipledatasource is our own class that inherits the Abstractroutingdatasource class, enabling Dynamic Data source switching--
<bean id= "Multipledatasource" class= "Cn.hicard.common.MultipleDataSource" >
<property name= "Defaulttargetdatasource" ref= "Readandwritedatasouce"/>
<property name= "Targetdatasources" >
<map>
<entry key= "Defaultdatasource" value-ref= "Readandwritedatasouce"/>
<entry key= "Readdatasource" value-ref= "Readdatasource"/>
</map>
</property>

</bean>
2. Creating an implementation class for dynamically switching data sources Multipledatasource
Import Org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
 * Multiple data source support, before calling DAO, execute Multipledatasource.changeread (), change to read <br/>
 * Read and write data source as default data source
& nbsp;*/
public class Multipledatasource extends abstractroutingdatasource{
private static final threadlocal< string> Datasourcekey = new inheritablethreadlocal<string> ();
/**  Change the current data source to read data source */
    public static void Changeread () {
    Datasourcekey.set (" Readdatasource ");
   }
   /*** Change the current data source to a read-write data source, which is the default data source  */
    public static void Changereadandwirte () {
& nbsp   Datasourcekey.set ("Readandwritedatasouce");
   }

Implementing the Determinecurrentlookupkey method This is the main way to get the data source
@Override
Protected Object Determinecurrentlookupkey () {
return Datasourcekey.get ();
}
}

3. Switch to the specified data source before invoking the database

@Service
public class Logserviceimpl implements Ilogservice {
@Resource
Private Ilogdao Logdao;
@Override
Public list<log> Search (map<string, object> paramter) throws Exception {
Multipledatasource.changeread ();//Toggle Data source
Return Logdao.search (paramter);
}

}