If your code makes it in here, you're likely having an issue with one of the following: } catch (NoSuchMethodException | SecurityException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) String userEmail = (String) method.invoke(aUser) Method method = aUser.getClass().getMethod("getEmail") Here's that same code, only now we'll invoke the getter method using reflection: Nothing fancy going on here (assuming you know what a repository is, if you don't I'd recommend reading about it here) now we invoke the getEmail() method to get the email address of user with ID 1. Let's assume we can load a user from the database by ID like so: For example, if we wanted to invoke the getter method for a User‘s email, it would be: You've seen what it looks like to “invoke” any of these methods. The User above is a super common Java bean that represents some user. Let's assume you've got a standard Java class that has some getter and setter methods like so: The Method class gives us access to some cool stuff… Namely the ability to “invoke” methods that you want to have invoked (programmatically). So, one of the keys to working with reflection in Java is to make use of the Method class. Reflection in Java is a way to call the methods of objects without needing the actual reference to those objects.Īnother way to say it is, you can programmatically execute methods with reflection in Java. This “execution of code written out as Strings” concept is very similar to what reflection in Java accomplishes.
If you've never used JavaScript before, then no worries, I'll have an in-depth explanation as to what's going on.įor you JavaScript coders out there, the eval() function is used so that you can write any strings you like inside of the function, and the JavaScript engine will interpret it and run it like it was native JS code. If you've ever used the JavaScript language before, you might be familiar with the eval() function.
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