how to pass values dynamically in config file

Question

I want to pass the value in the value tag of the property dynamically from the DB. Is this possible in Spring? And how ?

For example in the configuration below.

Answer 1

You can write a another Java class and make it as a bean in Application context and using Spring Expression Language, you have evaluate and get output of the method call.

XML configuration:

<property name="serviceClass" 
                 value="#{webServiceInfoFromDB.wsdlUrl}" />
<property name="username" 
                 value="#{webServiceInfoFromDB.username}" />

WeServiceInfoFromDB.java class:

class WebServiceInfoFromDB {

   public String getWsdlUrl() {
      // Get the Wsdl URL from DB.
      return wsdlUrl;
   }

   public String getUsername(){
      // get the username from DB
      return username;
   }

XML configuration in application context:

<bean id="webServiceInfoFromDB" class="WebServiceInfoFromDB">
   <property name="dataSource" ref="dataSource"/>
</bean>

Answer 2

You can setup property Place Holder with your properties file name that contains key-value pair.

<context:property-placeholder location="config.properties" />

The config.properties file looks like:

wsdl.url = http://server:8080/ServiceAccessPoint
webservice.username = guest
webservice.passward = guest123

Now you can modify your bean definition with ${key}

<bean id="proxyFactory" 
class="org.apache.cxf.jaxws.JaxWsProxyFactoryBean">
<property name="serviceClass" value="${wsdl.url}"/>
<property name="address" value="${wsdl.url}"/>
<property name="username" value="${webservice.username}"/>
<property name="password" value="${webservice.password}"/>