Java for Web Development Create Full-Stack Java Applications with Servlets, JSP Pages, MVC Pattern and Database Connectivity (Sarika Agarwal, Vivek Gupta) (Z-Library)

Java for Web Development Create Full-Stack Java Applications with Servlets, JSP Pages, MVC Pattern and Database Connectivity Sarika Agarwal Vivek Gupta www.bpbonline.com

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Dedicated to My beloved Son Mr. Kushagra Agarwal

About the Authors Sarika Agarwal is a professor with 16+ years of experience teaching Java technology Python. She has imparted training on Java, Python, C, C++ for more than 5000 students. Her interest area is Java, Android, machine learning, Natural Language Processing. She has cleared many certifications, including SCJP (Sun Certified Java Programmer), OWCD (Oracle Web component Developer), ACAD (Android Certified Application Developer), Android ATC Certified Trainer, MTA certifications (Software Testing Fundamentals, Operating System, Database Management System), IBM RAD certification. She has worked in NIIT as a Java Faculty and Engineering College professor. She has published papers in Journals and Scopus Index conferences. She is the author of the Book -Java in Depth. Vivek Gupta has completed his B.Tech from Uttar Pradesh Technical University in 2006 CDAC (Post Graduate Diploma in Computer Science) in 2006. 15+ years of experience in Java Application support and maintenance at all levels (L1, L2, and L3). Currently, working with Ventiv Technology as Technical Lead. He has worked in HCL, Cognizant Technology Solutions

About the Reviewer With about six years of experience in teaching, Ms. Jyoti Kumari is an Assistant Professor, an enthusiast in learning new technologies. She currently works at Keshav Mahavidyalaya, University of Delhi. She is also pursuing a Ph.D. in Information Technology at Amity University to carry her interest in research work. She also mentors graduate students in their project work such as creating android applications, web development, and so on. She was also a member of the editorial board of the magazine of the technical society of Computer Science department of the college.

Acknowledgement There are a few people I want to thank for the continued and ongoing support they have given me during the writing of this book. First and foremost, I would like to thank my husband, Mr. Amit Kumar, for continuous support and encouraging me to write the book — I could have never completed this book without his support. I am grateful to the excellent Java Community, from which I have learned and continue to learn a great deal. I would like to thank the reviewers who contributed many suggestions and improvements to my drafts. Thanks also go to many others with whom I have had conversations or email discussions over the course of writing the book. Any errors that remain are, of course, to be laid at my door. Special thanks to BPB Publications team, for the valuable support provided throughout the entire process. Finally, the writing of this book has been a great deal of work, and I could not have done it without the constant support of my family. My son, Kushagra Agarwal, has been very understanding, and I am looking forward to spending lots more time with all of them.

Preface Java, the only pure object-oriented language available today, is now used in almost all applications, from simple home appliances control systems to complex space control systems. It has also revolutionized applications from Intranet to the Internet. This book aims at imparting expertise in web application development using servlets and JavaServer Pages. You will learn to create a servlet, JSP pages, and connectivity with Database and deploy these applications on the Tomcat Server. Some Interview Questions with answers are also included. This book is meant for anyone who has an interest in Object-Oriented Programming and is aspiring to become a Java Programmer. The book covers all topics with basic examples and analogies. The book covers all topics related to Servlets and JSP like building GUI applications, reusing JavaBeans in JSP, and using custom tag libraries. This book is written to serve as a textbook for GBTU and for those who want to learn basic and advanced level web application development in java with their efforts. In each chapter, good worked Examples have been given. Chapter 1 aims to learn the connectivity of the Java Program with the Database; Chapter 2 covers Internationalization, which customizes an application according to specific languages and regions. Chapter 3 to 6 covers the Servlets, Inter Servlet Communications Sessions, etc. Chapter 7 to 10 Covers topics related to JSP pages, Custom tags, Directives, MVC architecture, and many more At the end of each chapter, some interview questions with answers are also given that may be useful to students of any discipline as MCA, B.Tech, M.Tech, M.Sc. I am sure that the students and the faculty will find this book very useful.

Critical evaluation and suggestions for improving the book will be highly appreciated and gratefully acknowledged.

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Table of Contents 1. Database Connectivity Introduction Structure Objectives Database Management ODBC Application Programming Interface (API) JDBC-API Categories of JDBC Drivers JDBC-ODBC bridge + ODBC driver Native-API driver Network protocol driver Thin Driver Querying a database Connecting to a database The connection object Loading the Driver and establishing the connection The JDBC URL A Sample JDBC URL Processing querying in a database Conclusion Multiple Choice Questions Answers Fill in the blanks

State True/False Questions Interview Questions 2. Internationalization (I18N) Introduction Structure Objective Localization (L10N) Locale Constructors of Locale Class Commonly used methods of Locale class Resource Bundle Constructor of ResourceBundle Methods of ResourceBundle Class Steps to develop the I18N-based application Internationalizing Date and Time (I18N with Date and Time) Methods of java.text.DateFormat Internationalizing with Numbers (I18N with Numbers) Conclusion Multiple Choice Questions 3. Introduction to Java Servlets Introduction Structure Objectives Webserver

Introduction to Servlets Characteristics of Servlets Comparison between Servlets and Applets Comparison between Servlets and other server-side scripting technologies CGI scripts Active Server Pages (ASP) Working of Servlets The GET and POST methods The Javax.servlet package Lifecycle of a Servlet Servlet Interface Creating a Servlet Creating the deployment descriptor (web.xml file) Conclusion Questions 4. HTTP Servlet Introduction Structure Objectives HTTP Servlet Need of HTTPServlet class HTTP Request and HTTP Response The GET and POST methods HttpServletRequest Interface Method of ServletRequest Interface Conclusion

Questions Multiple Choice Questions 5. Working with Servlet Sessions Introduction Structure Objective Session tracking Techniques to keep track of sessions in servlets URL Rewriting Hidden Form Fields Using the HttpSession Interface Cookies The javax.servlet.http.Cookie class Conclusion Questions 6. Inter-Servlet Communication Introduction Structure The RequestDispatcher Interface Method of ServletContext Interface Method to get the object of RequestDispatcher Methods of RequestDispatcher interface Implementing Inter servlet communication via a problem statement Tasklist Client Interface index.xhtml Code of FirstServlet

SendRedirect Difference between forward() and sendRedirect() method Conclusion Questions 7. Java Server Pages(JSP) Introduction Structure Objectives Need for JSP Difference between Servlet and JSP Advantages of JSP The JSP request-response cycle Lifecycle of JSP Structure of a JSP Page The directory structure of the JSP Page Conclusion Questions 8. Comment Tag and Scripting Element Structure Objectives JSP Elements Comment Tag Scripting Elements Scriptlet tag Expression Tag Declaration tag Implicit Objects

Conclusion Questions Select the Correct Option 9. JSP Directives Structure Objective Types Of Directives JSP directives The page directive Implicit Objects contentType extends errorPage isErrorPage import= “package list” language= “scripting language.” Session=true/false info= “servlet information” Buffer isELIgnored= “true/false” isThreadSafe autoFlush The include directive The Taglib directive Conclusion Questions 10. JSP Action Element and Custom Tags

Introduction Structure Objectives JSP Action Tags jsp:useBean action tag jsp:setProperty and jsp:getProperty action tags Jsp:forward action tag jsp:include action tag JSP custom tags Custom Tag Library Need of XML Custom Tags The structure of the TLD file The structure of the JSP File Expression Language(EL) Model View Controller (MVC) Architecture in JSP MVC Example in JSP Conclusion Questions 11. Introduction to Struts Introduction Structure Objective Features of Struts2 Components of Struts2 Architecture of Struts2 Creating a Struts Application