Handling Large XML files in XMLGenerator class change the path of the file you want to write XML entries private static final String filePath = "E:\xml\acc.xml"; when you run it will create data to file
XMLReader class also you want to change the path of the file. This class will read line by line and aggregare business object and then perfoem the business operation.
You will need to optimoze the code to perfomance at the moment this will run as a singal treaded application.