Visual COBOL® NEW APPLICATION MODERNIZATION TOOLS FOR THE JAVA DEVELOPER 00_COBOL2_AM.indb 1 4/19/21 5:08 PM Copyright © 2021 by Micro Focus. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted un-der Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc. 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to Micro Focus for permission should be addressed to the Legal Department, Micro Focus, 700 King Farm Blvd, Suite 125, Rockville, MD 20850, (301) 838-5000, fax (301) 838-5034. 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ISBN: 978-0-578-79047-3 This book was set in Akzidenz-Grotesk by Box Twelve Press. 00_COBOL2_AM.indb 2 4/19/21 5:08 PM Contents at a Glance CHAPTER 1 Introduction 1 CHAPTER 2 Visual COBOL and Eclipse 5 CHAPTER 3 What is Visual COBOL for JVM? 19 CHAPTER 4 A Short Guide to Procedural COBOL 29 CHAPTER 5 An Example Application 41 CHAPTER 6 A COBOL-Based REST Service 67 CHAPTER 7 Automated Testing 99 CHAPTER 8 User Interface Modernization 127 CHAPTER 9 Containerizing COBOL Applications 155 CHAPTER 10 COBOL and Microservices 185 00_COBOL2_AM.indb 3 4/19/21 5:08 PM 00_COBOL2_AM.indb 4 4/19/21 5:08 PM Contents CHAPTER 1 Introduction 1 What Is Visual COBOL for JVM? ...................................................................................................................... 1 Why Have We Written This Book? .................................................................................................................. 2 Who Is This Book For? .............................................................................................................................................. 2 Prerequisites ...................................................................................................................................................................... 3 Downloading the Examples ................................................................................................................................... 4 Summary ............................................................................................................................................................................... 4 CHAPTER 2 Visual COBOL and Eclipse 5 Hello World ......................................................................................................................................................................... 5 Creating COBOL JVM Projects in Eclipse ................................................................................................ 7 Using Maven with Visual COBOL ..................................................................................................................10 Summary ............................................................................................................................................................................18 CHAPTER 3 What is Visual COBOL for JVM? 19 COBOL Dialects ..........................................................................................................................................................19 What is Managed Code? ......................................................................................................................................20 COBOL Source Formats ......................................................................................................................................21 The Visual COBOL Object Model .................................................................................................................23 Summary ............................................................................................................................................................................27 CHAPTER 4 A Short Guide to Procedural COBOL 29 COBOL Applications ................................................................................................................................................30 Structure of a COBOL program ......................................................................................................................31 Procedure Division .....................................................................................................................................................34 Copybooks .......................................................................................................................................................................38 Summary ............................................................................................................................................................................40 00_COBOL2_AM.indb 5 4/19/21 5:08 PM vi Contents CHAPTER 5 An Example Application 41 Introducing the Example.......................................................................................................................................41 Generating Example Data ...................................................................................................................................59 Calling COBOL from Java ...................................................................................................................................61 Summary ............................................................................................................................................................................66 CHAPTER 6 A COBOL-Based REST Service 67 The Application .............................................................................................................................................................67 The Interoperation Layer ......................................................................................................................................70 The MonthlyInterest Class ...................................................................................................................................85 Creating a REST Interface .................................................................................................................................88 Summary ............................................................................................................................................................................97 CHAPTER 7 Automated Testing 99 Strategies for Testing ..............................................................................................................................................99 Introducing MFUnit .................................................................................................................................................101 Testing the BusinessRules Layer ...............................................................................................................107 Testing the Interoperation Layer ..................................................................................................................117 Testing the Application End-to-End ..........................................................................................................120 Summary .......................................................................................................................................................................126 CHAPTER 8 User Interface Modernization 127 UI Choices ....................................................................................................................................................................127 The Credit Service UI Application ..............................................................................................................130 Getting Started with React ..............................................................................................................................135 Summary .........................................................................................................................................................................154 00_COBOL2_AM.indb 6 4/19/21 5:08 PM Contents