Passing properties to a Spring context

I'm using Spring to handle RMI calls to some remote server. It is straightforward to construct an application context and obtain the bean for remote invocations from within the client:

ApplicationContext context = new ApplicationContext("classpath:context.xml");

MyService myService = (MyService ) context.getBean( "myService " );

However I don't see a simple way to pass properties into the configuration. For example if I want to determine the host name for the remote server at runtime within the client.

I'd ideally have an entry in the Spring context like this:

<bean id="myService" class="org.springframework.remoting.rmi.RmiProxyFactoryBean">
  <property name="serviceUrl" value="rmi://${webServer.host}:80/MyService"/>
  <property name="serviceInterface" value="com.foo.MyService"/>
</bean>

and pass the properties to the context from the client as a parameter.

I can use a PropertyPlaceholderConfigurer in the context to substitute for these properties, but as far as I can tell this only works for properties read from a file.

I have an implementation that addresses this (added as an answer) but I'm looking for a standard Spring implementation to avoid rolling my own. Is there another Spring configurer (or anything else) to help initialise the configuration or am I better off looking at java config to achieve this?

java spring rmi

Edit Report

My existing solution involves defining a new MapAwareApplicationContext that takes a Map as an additional constructor argument.

public MapAwareApplicationContext(final URL[] configURLs,
    final String[] newConfigLocations,
    final Map<String, String> additionalProperties) {
    super(null);

    //standard constructor content here

    this.map = new HashMap<String, String>(additionalProperties);

    refresh();
}

It overrides postProcessBeanFactory() to add in a MapAwareProcessor:

protected void postProcessBeanFactory(
    final ConfigurableListableBeanFactory beanFactory) {
    beanFactory.addBeanPostProcessor(new MapAwareProcessor(this.map));
    beanFactory.ignoreDependencyInterface(MapAware.class);
}

The MapAwareProcessor implements postProcessBeforeInitialization() to inject the map into any type that implements the MapAware interface:

public Object postProcessBeforeInitialization(final Object bean, 
        final String beanName) {
    if (this.map != null && bean instanceof MapAware) {
        ((MapAware) bean).setMap(this.map);
    }

    return bean;
}

I then add a new bean to my config to declare a MapAwarePropertyPlaceholderConfigurer:

<bean id="propertyConfigurer"
  class="com.hsbc.r2ds.spring.MapAwarePropertyPlaceholderConfigurer"/>

The configurer implements MapAware, so it will be injected with the Map as above. It then implements resolvePlaceholder() to resolve properties from the map, or delegate to the parent configurer:

protected String resolvePlaceholder(final String placeholder, 
        final Properties props, final int systemPropertiesMode) {
    String propVal = null;
    if (this.map != null) {
        propVal = this.map.get(placeholder);
    }
    if (propVal == null) {
        propVal = super.resolvePlaceholder(placeholder, props);
    }
    return propVal;


                        
                        
                            answered 2009-07-06T10:10:08.167

Passing properties to a Spring context

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