Difference between ClassLoader.getSystemResourceAsStream and getClass().getResourceAsStream()

Question

Given this code:

/* 1 */ InputStream in1 = ClassLoader.getSystemResourceAsStream(\"foobar.txt\");
/* 2 */ InputStream in2 = this.getClass().getResourceAsStream(\         


        

Answer 1

The key difference is the class loader.

The following uses the System ClassLoader
ClassLoader.getSystemResourceAsStream("foobar.txt");

While this one uses the Classloader returned by getClass()
this.getClass().getResourceAsStream("/foobar.txt");

In other words, whether both statements behave exactly the same or not, depends on the application classloader. For a simple application, both refer to the same classloader. However, for most applications (like a web application running within Servlet container), that will not be the case.

In general, I would say getClass().getResourceAsStream() will be the better choice as it will use the same classloader as the Class the code belongs to.