How defining private static final field in multiple ways matter

What is the difference between 

 private static final String JDBC_URL = getURL();

and then defining the getURL() like:

private static String getURL() {
        return "jdbc:mysql://localhost:3306/";
    }

with the following code:

private static final String JDBC_URL = "jdbc:mysql://localhost:3306/";

I found that writing mock test was easier with the above one. I might be wrong. Just wanted to know if both ways are same. Thanks.

Jon Skeet
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The second way is a compile-time constant, so elsewhere in your code when you refer to the value, it won't actually refer to the field - it will just have the value baked in.

Unless you start messing with the field via reflection or something similarly nasty you shouldn't notice any semantic differences, but that will be a difference in the bytecode.

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