If I have a client wants to access service across multiple server, how should I config?

For example, I have a Client (client A) and Server B, C, D.
Client A can choose to connect Server B, C or D at different situation but with the same controller. How can I do this?

For example,
PHP Code:
<bean class="example.SimpleObject">
    <
property name="accountService"><ref bean="accountService"/></property>
</
bean>

<
bean id="accountService" class="org.springframework.remoting.caucho.HessianProxyFactoryBean">
    <
property name="serviceUrl"><value>http://hostB:8080/AccountService</value></property>
    
<property name="ServiceInterface"><value>example.AccountService</value></property>
</
bean
If I want to accountService having serviceUrl = host B, C or D for different situation, how can I do it?

Thanks