[FIXED] How to load system properties file in Spring?

Issue

I have a properties file which I would like loaded in to System Properties so that I can access it via System.getProperty("myProp"). Currently, I'm trying to use the Spring <context:propert-placeholder/> like so:

<context:property-placeholder location="/WEB-INF/properties/webServerProperties.properties" />

However, when I try to access my properties via System.getProperty("myProp") I'm getting null. My properties file looks like this:

myProp=hello world

How could I achieve this? I'm pretty sure I could set a runtime argument, however I'd like to avoid this.

Thanks!

Solution

While I subscribe to the Spirit of Bozho's answer, I recently also had a situation where I needed to set System Properties from Spring. Here's the class I came up with:

Java Code:

public class SystemPropertiesReader{

    private Collection<Resource> resources;

    public void setResources(final Collection<Resource> resources){
        this.resources = resources;
    }

    public void setResource(final Resource resource){
        resources = Collections.singleton(resource);
    }

    @PostConstruct
    public void applyProperties() throws Exception{
        final Properties systemProperties = System.getProperties();
        for(final Resource resource : resources){
            final InputStream inputStream = resource.getInputStream();
            try{
                systemProperties.load(inputStream);
            } finally{
                // Guava
                Closeables.closeQuietly(inputStream);
            }
        }
    }

}

Spring Config:

<bean class="x.y.SystemPropertiesReader">

    <!-- either a single .properties file -->
    <property name="resource" value="classpath:dummy.properties" />

    <!-- or a collection of .properties file -->
    <property name="resources" value="classpath*:many.properties" />

    <!-- but not both -->

</bean>

Answered By - Sean Patrick Floyd
Answer Checked By - Katrina (JavaFixing Volunteer)