TemplateMethodDemo.java

abstract class AbstractDocumentGenerator{
	
	//THIS IS TEMPLATE METHOD
	public final File generate() {
		Document defaultDocument = prepareDocumentByDefault();
		Document refinedDocument = redefineDocument(defaultDocument);
		String templatePath = getTemplatePath();
		String outputName = getOutputName();
		return DocFactory.generate(refinedDocument, templatePath, outputName);
	}
	
	//This method is implemented at this class, can not be overridden
	private Document prepareDocumentByDefault() {
		Document document = new Document();
		//TODO: prepare default here 
		return document;
	}

	//This is hook/default method which can be overridden by subclasses
	protected Document redefineDocument(Document defaultDocument) {
		return defaultDocument;
	}

	//These method must be implemented by subclass
	protected abstract String getOutputName();
	protected abstract String getTemplatePath();
	
}

class PaymentRequestDocumentGenerator extends AbstractDocumentGenerator {
	@Override
	protected String getOutputName() {
		return "payment_request.pdf";
	}

	@Override
	protected String getTemplatePath() {
		return "/home/document_template/payment_request.docx";
	}	
	
}

class StandingOrderDocumentGenerator extends AbstractDocumentGenerator {
	@Override
	protected String getOutputName() {
		return "standing_order.pdf";
	}

	@Override
	protected String getTemplatePath() {
		return "/home/document_template/standing_order.docx";
	}
	
	//Override the default method
  	@Override
	protected Document redefineDocument(Document defaultDocument) {
		defaultDocument.setDescription("Overriden the default");
		return defaultDocument;
	}
	
}