jmx mbean server throw InstanceAlreadyExistsException when change c3p0 version

Question

What are the differences between c3p0-0.9.1.2 and c3p0-0.9.5 that mean that when I want to register an MBean with DynamicPooledDataSourceManagerMBean in 0.9.1.2 everything is okay, but when I use 0.9.5 then com.sun.jmx.mbeanserver.Repository throws an javax.management.InstanceAlreadyExistsException.

I use spring as my container so the bean definition for DynamicPooledDataSourceManagerMBean is like this:

<bean id="register" class="com.mchange.v2.c3p0.management.DynamicPooledDataSourceManagerMBean">
   <constructor-arg index="0" ref="dataSource"/>
   <constructor-arg index="1" value="my.pool.connection:type=c3p0,name=Main"/>
   <constructor-arg index="2" ref="mbeanServer"/>
</bean>

which the dataSource ref definition is a com.mchange.v2.c3p0.ComboPooledDataSource and defined like this:

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" lazy-init="true" >
        and a lot of datasource config

and the mbeanSever is a Spring org.springframework.jmx.support.MBeanServerFactoryBean which is defined like this:

<bean name="mbeanServer"
    class="org.springframework.jmx.support.MBeanServerFactoryBean">
    <property name="locateExistingServerIfPossible" value="true" />
    <property name="registerWithFactory" value="true"></property>
</bean>

Answer 1

The problem, as @SteveWaldman said, was I tried to register my datasources into MBean server which c3p0 registered them before. So what I should have done was nothing. But there were some modification need to be done to what c3p0 registed. c3p0 register datasource with a name like this:

com.mchange.v2.c3p0:type=PooledDataSource,identityToken=1hgeowz961y14x0ldebkgx|1‌​23f9b8,name=Main

I would like to avoid adding identityToken so as said here I create a c3p0.properties file and put this line into it:

com.mchange.v2.c3p0.management.ExcludeIdentityToken=true

That was pretty much everything I had to do for my case. Thanks to @StevenWaldman.