Monday, August 30, 2010

Quarreling with classloaders

I admit that most of the quarreling, if not all of it, came from my not too deep knowledge of the subject. Anyway, at least I've learned something more.

Now that I know how to change the endpoint defined in a WSDL I was trying to put this knowledge to good use. We have a project that encapsulates the access to various web services, and we release it as a jar file that is normally used in web applications, in particular the one I'm mostly working on in these days. To easily let the administrator of the web application decide whether to use a monitoring application like wsmonitor I prepared a sevices.properties file:
proxyEnabled=true;
proxyAddress=http://...
Being test-infected I wrote a simple explorative test:

@Test
public void testLoadProperties() throws IOException {
System.out.println("testLoadProperties");
Properties properties = new Properties();
InputStream systemResourceAsStream = ClassLoader.getSystemResourceAsStream("path/to/my/services.properties");
properties.load(systemResourceAsStream);
assertNotNull(properties.getProperty("proxyEnabled"));
}
Green bar, so I put the code in the service class. Well actually before that I wrote another small (failing) test:

@Test
public void testPropertiesAreCorrectlyInitialized(){
System.out.println("testPropertiesAreCorrectlyInitialized");
assertNotNull(MyService.properties.getProperty("proxyEnabled"));
}
After the green bar I switched to the webapp and started it, but the isProxyEnabled method of the service, which simply performs a test on the value of the isProxyEnabled property always returned false. If you are wondering... yes, there are the corresponding tests, which are not reported for the sake of simplicity.

After some researches, and mostly thanks to Dave Lander's contribution to this discussion, I've found the problem and changed my loading instructions:

InputStream is = MyService.class.getClassLoader().getResourceAsStream("path/to/my/services.properties");
properties.load(is);


Funny how simple things are when you know them, aren't they?

1 comment:

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