How do I call the function in the Java file in the code behind?

Hello,

I have a java file ("test.java") and I want to call one of the function in the java and also pass the parameter to this function.  How do I do it?  Thanks

 

Here is the "test.java" looks like and I want to call the function private static String encrypt(String key, String clearText), how do I do it?

import java.security.*;
Go to the complete details ...