Generating classes at runtime and invoking their methods with and without the use of Reflection in Java

2 min readOct 30, 2020

The generation of classes at runtime is an advanced topic that requires a lot of knowledge that can be reduced if you use particular libraries that perform the most complex functions to accomplish this task.
So, for this purpose, we can use the ClassFactory component and the sources generating components of the Burningwave Core library.

To use the ClassFactory you should simply add the following to your projects dependencies:

Once the sources have been set in UnitSourceGenerator objects, they must be passed to loadOrBuildAndDefine method of ClassFactory with the ClassLoader where you want to define newly generated classes.

This method performs the following operations: tries to load all the classes present in the UnitSourceGenerator through the class loader, if at least one of these is not found it proceeds to compile all the UnitSourceGenerators and uploading their classes on class loader: in this case, keep in mind that if a class with the same name was previously loaded by the class loader, the compiled class will not be uploaded. If you need more information you can:

Once the classes have been compiled and loaded, it is possible to invoke their methods in several ways, as shown at the end of the example below.

In this short article we have learned how to generate classes at runtime in Java, how to load them and create instances; the complete source is available at this at this page and for more articles about Burningwave Core you can go to the main page.




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