Obtaining an Array class with Java reflection

This morning I needed to find and invoke a method reflectively that had an array parameter. It took me a few minutes to figure out how to get the class representing say a char[].

As a reminder, some other ways to get Class instances are:

• Class.forName("my.SillyClass") - for obtaining the Class for my.SillyClass by name
• SillyClass.class - for obtaining the class by type (preferred to the above for type safety)
• Integer.TYPE - for obtaining the Class for any primitive type via their wrapper class

An array is an object and has a class, but I wasn't aware of any way to do the equivalent of the above for an array of some type. One way is to use Class.forName() with the array class signature:

• Class.forName("[C") - for a char[]
• Class.forName("[Ljava.lang.String;") - for a String[]

But then my Java guru Tim Eck pointed out that you can just do:

• char[].class - for a char[]

Hope that helps someone out there!

Alex Miller lives in St. Louis. He writes code for a living and currently work for Terracotta Tech on the Terracotta open-source Java clustering product. Prior to Terracotta he worked at BEA Systems and was Chief Architect at MetaMatrix. His main language for the last decade has been Java, although Alex have been paid to program in several languages over the years (C++, Python, Pascal, etc). Alex is a DZone MVB and is not an employee of DZone and has posted 43 posts at DZone. You can read more from them at their website.