Java APIs, Extensions and Libraries

Transcription

1 Java APIs, Extensions and Libraries With JavaFX, JDBC, jmod, jlink, Networking, and the Process API Second Edition Kishori Sharan

2 Java APIs, Extensions and Libraries: With JavaFX, JDBC, jmod, jlink, Networking, and the Process API Kishori Sharan Montgomery, Alabama, USA ISBN-13 (pbk): ISBN-13 (electronic): Library of Congress Control Number: Copyright 2018 by Kishori Sharan This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Managing Director, Apress Media LLC: Welmoed Spahr Acquisitions Editor: Steve Anglin Development Editor: Matthew Moodie Coordinating Editor: Mark Powers Cover designed by estudiocalamar Cover image designed by Freepik ( Distributed to the book trade worldwide by Springer Science+Business Media New York, 233 Spring Street, 6th Floor, New York, NY Phone SPRINGER, fax (201) , orders-ny@springer-sbm.com, or visit Apress Media, LLC is a California LLC and the sole member (owner) is Springer Science + Business Media Finance Inc (SSBM Finance Inc). SSBM Finance Inc is a Delaware corporation. For information on translations, please editorial@apress.com; for reprint, paperback, or audio rights, please bookpermissions@springernature.com. Apress titles may be purchased in bulk for academic, corporate, or promotional use. ebook versions and licenses are also available for most titles. For more information, reference our Print and ebook Bulk Sales web page at Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the book s product page, located at For more detailed information, please visit Printed on acid-free paper

3 Contents About the Author...xvii About the Technical Reviewer...xix Acknowledgments...xxi Introduction...xxiii Chapter 1: Introduction to Swing... 1 What Is Swing?... 2 The Simplest Swing Program... 3 Components of a JFrame... 7 Adding Components to a JFrame... 9 Some Utility Classes The Point Class The Dimension Class The Insets Class The Rectangle Class Layout Managers FlowLayout BorderLayout CardLayout BoxLayout GridLayout GridBagLayout SpringLayout GroupLayout The null Layout Manager iii

4 Creating a Reusable JFrame Event Handling Handling Mouse Events Summary Chapter 2: Swing Components What Is a Swing Component? JButton JPanel JLabel Text Components JTextComponent JTextField JPasswordField JFormattedTextField JTextArea JEditorPane JTextPane Validating Text Input Making Choices JSpinner JScrollBar JScrollPane JProgressBar JSlider JSeparator Menus JToolBar JToolBar Meets the Action Interface JTable iv

5 JTree JTabbedPane and JSplitPane Custom Dialogs Standard Dialogs File and Color Choosers JFileChooser JColorChooser JWindow Working with Colors Working with Borders Working with Fonts Validating Components Painting Components and Drawing Shapes Immediate Painting Double Buffering JFrame Revisited Summary Chapter 3: Advanced Swing Using HTML in Swing Components Threading Model in Swing Pluggable Look and Feel Drag and Drop Multiple Document Interface Application The Toolkit Class Decorating Components Using JLayer Translucent Windows Shaped Window Summary v

6 Chapter 4: Network Programming What Is Network Programming? Network Protocol Suite IP Addressing Scheme IPv4 Addressing Scheme IPv6 Addressing Scheme Special IP Addresses Loopback IP Address Unicast IP Address Multicast IP Address Anycast IP Address Broadcast IP Address Unspecified IP Address Port Numbers Socket API and Client-Server Paradigm The Socket Primitive The Bind Primitive The Listen Primitive The Accept Primitive The Connect Primitive The Send/Sendto Primitive The Receive/ReceiveFrom Primitive The Close Primitive Representing a Machine Address Representing a Socket Address Creating a TCP Server Socket Creating a TCP Client Socket Putting a TCP Server and Clients Together vi

7 Working with UDP Sockets Creating a UDP Echo Server A Connected UDP Socket UDP Multicast Sockets URI, URL, and URN URI and URL as Java Objects Accessing the Contents of a URL Non-Blocking Socket Programming Socket Security Permissions Asynchronous Socket Channels Setting Up an Asynchronous Server Socket Channel Setting Up an Asynchronous Client Socket Channel Putting the Server and the Client Together Datagram-Oriented Socket Channels Creating the Datagram Channel Setting the Channel Options Sending Datagrams Multicasting Using Datagram Channels Creating the Datagram Channel Setting the Channel Options Binding the Channel Setting the Multicast Network Interface Joining the Multicast Group Receiving a Message Closing the Channel Further Reading Summary vii

8 Chapter 5: JDBC API What Is the JDBC API? System Requirements Types of JDBC Drivers JDBC Native API Driver JDBC-Net Driver JDBC Driver A Brief Overview of Apache Derby Downloading Derby Installing Derby Derby Installation Files Configuring Derby Running the Derby Server Creating a Database Table Oracle Database Adaptive Server Anywhere Database SQL Server Database DB2 Database MySQL Database Apache Derby Database Connecting to a Database Obtaining the JDBC Driver Setting Up the Module Path Registering a JDBC Driver Constructing a Connection URL Establishing the Database Connection Setting the Auto-Commit Mode Committing and Rolling Back Transactions viii

9 Transaction Isolation Level Dirty Read Non-Repeatable Read Phantom Read JDBC-Types-to-Java-Types Mapping Knowing About the Database Executing SQL Statements Results of Executing a SQL Statement Using the Statement Interface Using the PreparedStatement Interface CallableStatement Interface Processing Result Sets What Is a ResultSet? Getting a ResultSet Getting the Number of Rows in a ResultSet Bidirectional Scrollable ResultSets Scrolling Through Rows of a ResultSet Knowing the Cursor Position in a ResultSet Closing a ResultSet Making Changes to a ResultSet Inserting a Row Using a ResultSet Updating a Row Using a ResultSet Deleting a Row Using a ResultSet Handling Multiple Results from a Statement Getting a Result Set from a Stored Procedure MySQL Database Adaptive Server Anywhere Database Oracle Database SQL Server Database DB2 Database Apache Derby Database ix

10 ResultSetMetaData Using RowSets Creating a RowSet Working with a Large Object (LOB) Retrieving LOB Data Creating a LOB Data Batch Updates Savepoints in a Transaction Using a DataSource Retrieving SQL Warnings Enabling JDBC Trace Summary Chapter 6: Java Remote Method Invocation What Is Java Remote Method Invocation? The RMI Architecture Developing an RMI Application Writing the Remote Interface Implementing the Remote Interface Writing the RMI Server Program Writing the RMI Client Program Separating the Server and Client Code Generating Stub and Skeleton Running the RMI Application Running the RMI Registry Running the RMI Server Running an RMI Client Program Troubleshooting an RMI Application java.rmi.stubnotfoundexception java.rmi.server.exportexception x

11 java.security.accesscontrolexception java.lang.classnotfoundexception Debugging an RMI Application Dynamic Class Downloading Garbage Collection of Remote Objects Summary Chapter 7: Java Native Interface What Is the Java Native Interface? System Requirements Getting Started with the JNI Writing the Java Program Compiling the Java Program Creating the C/C++ Header File Writing the C/C++ Program Creating a Shared Library Running the Java Program Native Function Naming Rules Data Type Mapping Using JNI Functions in C/C Working with Strings Working with Arrays Accessing Java Objects in Native Code Getting a Class Reference Accessing Fields and Methods of a Java Object/Class Creating Java Objects Exception Handling Handle the Exception in Native Code Handling the Exception in Java Code Throwing a New Exception from Native Code xi

12 Creating an Instance of the JVM Synchronization in Native Code Summary Chapter 8: Introduction to JavaFX What Is JavaFX? History of JavaFX System Requirements The JavaFX Modules JavaFX Source Code JavaFX API Documentation Your First JavaFX Application Creating the HelloJavaFX Class Overriding the start() Method Showing the Stage Launching the Application Adding the main() Method Adding a Scene to the Stage Improving Your First JavaFX Application The Lifecycle of a JavaFX Application Terminating a JavaFX Application What Are Properties and Bindings? Properties and Bindings in JavaFX Using Properties in JavaFX Beans Handling Property Invalidation Events Handling Property Change Events Property Bindings in JavaFX Observable Collections xii

13 Event Handling Event Processing Mechanism Creating Event Filters and Handlers Registering Event Filters and Handlers Layout Panes Controls Using 2D Shapes Drawing on a Canvas Applying Effects Applying Transformations Animation Using the Timeline Animation FXML Printing Summary Chapter 9: Scripting in Java What Is Scripting in Java? Executing Your First Script Using Other Scripting Languages Exploring the javax.script Package The ScriptEngine and ScriptEngineFactory Interfaces The AbstractScriptEngine Class The ScriptEngineManager Class The Compilable Interface and the CompiledScript Class The Invocable Interface The Bindings Interface and the SimpleBindings Class The ScriptContext Interface and the SimpleScriptContext Class The ScriptException Class Discovering and Instantiating Script Engines xiii

14 Executing Scripts Passing Parameters Passing Parameters from Java Code to Scripts Passing Parameters from Scripts to Java Code Advanced Parameter Passing Techniques Bindings Scope Defining the Script Context Putting Them Together Using a Custom ScriptContext Return Value of the eval() Method Reserved Keys for Engine Scope Bindings Changing the Default ScriptContext Sending Script Output to a File Invoking Procedures in Scripts Implementing Java Interfaces in Scripts Using Compiled Scripts Using Java in Scripting Languages Declaring Variables Importing Java Classes Creating and Using Java Objects Using Overloaded Java Methods Using Java Arrays Extending Java Classes and Implementing Interfaces Using Lambda Expressions Implementing a Script Engine The Expression Class The JKScriptEngine Class The JKScriptEngineFactory Class xiv

15 Packaging the JKScript Files Using the JKScript Script Engine The jrunscript Command-Line Shell The Syntax Execution Modes of the Shell Listing Available Script Engines Adding a Script Engine to the Shell Using Other Script Engines Passing Arguments to Scripts The jjs Command-Line Tool JavaFX in Nashorn Summary Chapter 10: Process API What Is the Process API? Knowing the Runtime Environment The Current Process Querying Process State Comparing Processes Creating a Process Obtaining a Process Handle Terminating Processes Managing Process Permissions Summary Chapter 11: Packaging Modules The JAR Format What Is a Multi-Release JAR? Creating Multi-Release JARs Rules for Multi-Release JARs Multi-Release JARs and JAR URL Multi-Release Manifest Attribute xv

16 The JMOD Format Using the jmod Tool Summary Chapter 12: Custom Runtime Images What Is a Custom Runtime Image? No More rt.jar Creating Custom Runtime Images Binding Services Using Plugins with the jlink Tool The jimage Tool Summary Index xvi

17 About the Author Kishori Sharan works as a senior software engineer lead at IndraSoft, Inc. He earned a master s of science degree in computer information systems from Troy State University, Alabama. He is a Sun-certified Java 2 programmer and has over 20 years of experience in developing enterprise applications and providing training to professional developers using the Java platform. xvii

18 About the Technical Reviewer Manuel Jordan Elera is an autodidactic developer and researcher who enjoys learning new technologies for his own experiments and creating new integrations. Manuel won the 2010 Springy Award Community Champion and Spring Champion In his little free time, he reads the Bible and composes music on his guitar. Manuel is known as dr_pompeii. He has technically reviewed numerous books for Apress, including Pro Spring Messaging (2017), Pro Spring, 4th Edition (2014), Practical Spring LDAP (2013), Pro JPA 2, Second Edition (2013), and Pro Spring Security (2013). Read his 13 detailed tutorials about many Spring technologies, contact him through his blog at and follow him on his Twitter account xix

19 Acknowledgments I would like to thank my family members and friends for their encouragement and support my mom Pratima Devi; my elder brothers, Janki Sharan and Dr. Sita Sharan; my nephews, Gaurav and Saurav; my sister Ratna; and my friends Karthikeya Venkatesan, Rahul Nagpal, Ravi Datla, Mahbub Choudhury, Richard Castillo, and many more friends not mentioned here. My wife, Ellen, was always patient as I spent long hours at my computer desk working on this book. I want to thank her for all of her support in writing this book. Special thanks to my friend Preethi Vasudev for offering her valuable time and providing solutions to the exercises in this book. She likes programming challenges particularly Google Code Jam. I bet she enjoyed solving the exercises in each chapter of this book. My sincere thanks are due to the wonderful team at Apress for their support during the publication of this book. Thanks to Mark Powers, the editorial operations manager, for providing excellent support. Thanks to the technical reviewer, Manuel Jordan Elera, for his technical insights and feedback during the review process; he was instrumental in weeding out several technical errors. Last but not least, my sincere thanks to Steve Anglin, the lead editor at Apress, for taking the initiative for the publication of this book. xxi

20 Introduction How This Book Came About My first encounter with the Java programming language was during a one-week Java training session in I did not get a chance to use Java in a project until I read two Java books and took a Java 2 programmer certification examination. I did very well on the test, scoring 95 percent. The three questions that I missed on the test made me realize that the books that I had read did not adequately cover details about all the topics necessary. I made up my mind to write a book on the Java programming language. So, I formulated a plan to cover most of the topics that a Java developer needs to use the Java programming language effectively in a project, as well as to get a certification. I initially planned to cover all essential topics in Java in 700 to 800 pages. As I progressed, I realized that a book covering most of the Java topics in detail could not be written in 700 to 800 pages. One chapter alone that covered data types, operators, and statements spanned 90 pages. I was then faced with the question, Should I shorten the content of the book or include all the details that I think a Java developer needs? I opted for including all the details in the book, rather than shortening its content to keep the number of pages low. It has never been my intent to make lots of money from this book. I was never in a hurry to finish this book because that rush could have compromised the quality and coverage. In short, I wrote this book to help the Java community understand and use the Java programming language effectively, without having to read many books on the same subject. I wrote this book with the plan that it would be a comprehensive one-stop reference for everyone who wants to learn and grasp the intricacies of the Java programming language. One of my high school teachers used to tell us that if one wanted to understand a building, one must first understand the bricks, steel, and mortar that make up the building. The same logic applies to most of the things that we want to understand in our lives. It certainly applies to an understanding of the Java programming language. If you want to master the Java programming language, you must start by understanding its basic building blocks. I have used this approach throughout this book, endeavoring to build each topic by describing the basics first. In the book, you will rarely find a topic described without first learning its background. Wherever possible, I have tried to correlate the programming practices with activities in our daily life. Most of the books about the Java programming language either do not include any pictures at all or have only a few. I believe in the adage, A picture is worth a thousand words. To the reader, a picture makes a topic easier to understand and remember. I have included plenty of illustrations in the book to aid readers in understanding and visualizing the contents. Developers with little or no programming experience have difficulty in putting things together to make it a complete program. Keeping them in mind, the book contains over 200 complete Java programs that are ready to be compiled and run. I spent countless hours doing research for writing this book. My main source of research was the Java Language Specification, whitepapers and articles on Java topics, and Java Specification Requests (JSRs). I also spent quite a bit of time reading the Java source code to learn more about some of the Java topics. Sometimes, it took a few months researching a topic before I could write the first sentence on the topic. Finally, it was always fun to play with Java programs, sometimes for hours, to add them to the book. xxiii

21 Introduction Introduction to the Second Edition I am pleased to present the second edition of the Java APIs, Extensions, and Libraries book. It is the third book in the three-volume series. It was not possible to include all JDK9 changes in the one volume. I have included JDK9-specific changes at appropriate places in the three volumes, including this one. If you are interested in learning only JDK9-specific topics, I suggest that you read my Java 9 Revealed book ( which contains only JDK9-specific topics. There are several changes in this edition and they are as follows. I dropped the chapter on applets, which was part of the first edition. The Applet API in JDK9 has been deprecated and all modern browsers either have discontinued or will discontinue the support for the Java plug-in, which is needed to run applets. I consider the Applet API dead for any new development. This was the reason I dropped it in this edition. I added the following three chapters to this edition: Process API (Chapter 10), Packaging Modules (Chapter 11), and Custom Runtime Images (Chapter 11). I felt that this book was missing a chapter on the Process API. JDK9 added several enhancements to the Process API. I thought that a chapter on the Process API would be a good addition to this book. I added Chapter 10 to cover the Process API including enhancements to the Process API in JDK9. Java applications were packaged in JARs before JDK9. JDK9 has added several enhancements to the JAR format. JDK9 added a new type of JAR called the multi-release JAR, which can package code for a library for multiple JDK releases. You can also package modules in JMOD format that can be used at compile-time and link time. Chapter 11 covers the enhancements to the JAR format and the new JMOD format. This chapter also covers how to use the jmod tool to work with JMOD files. JDK9 added a new phase between compile-time and runtime, which is called the linking phase (or link time). You can use the jlink tool, which was introduced in JDK9, to link application modules and JDK modules to their dependencies to create a custom runtime image. The custom runtime image will contain only these modules that are needed by your application, not the entire Java runtime modules thus reducing the size of the runtime image. Chapter 12 covers how to create custom runtime images using the jlink tool. Apart from these changes, I updated all the chapters from the first edition. I edited the contents to make them flow better, changed or added new examples, and updated the contents to include JDK9-specific features. It is my sincere hope that this edition of the book will help you learn Java better. Structure of the Book This is the third book in the three-book Beginning Java series. This book contains 12 chapters. The chapters cover the Java libraries and extensions such as Swing, JavaFX, Nashorn, Java Native Interface, network programming, JDBC, jmod and jlink tools, etc. If you have intermediate level Java experience, you can conquer the chapters in any order except for the first three chapters, which should be read in order. The new features of Java 9 are included wherever they fit in the chapters. Chapters 11 and 12 cover JDK9-specific features exclusively. Audience This book is designed to be useful to anyone who wants to learn the Java programming language. If you are a beginner, with little or no programming background in Java, you are advised to read the companion book Beginning Java 9 Fundamentals (second edition) and Java Language Features (second edition) before reading this book. This book contains topics of various degrees of complexity. As a beginner, if you find yourself overwhelmed while reading a section in a chapter, you can skip to the next section or the next chapter and revisit it later when you gain more experience. xxiv

22 Introduction If you are a Java developer with an intermediate or advanced level of experience, you can jump to a chapter or a section in a chapter directly. If you are reading this book to get a certification in the Java programming language, you need to read almost all of the chapters, paying attention to all of the detailed descriptions and rules. Most of the certification programs test your fundamental knowledge of the language, not advanced knowledge. You need to read only those topics that are part of your certification test. Compiling and running over 200 complete Java programs will help you prepare for your certification. If you are a student who is attending a class in the Java programming language, you should read the chapters of this book selectively. You need to read only those chapters that are covered in your class syllabus. I am sure that you, as a Java student, do not need to read the entire book page by page. How to Use This Book This book is the beginning, not the end, of gaining the knowledge of the Java programming language. If you are reading this book, it means you are heading in the right direction to learn the Java programming language, which will enable you to excel in your academic and professional career. However, there is always a higher goal for you to achieve and you must constantly work hard to achieve it. The following quotations from some great thinkers may help you understand the importance of working hard and constantly looking for knowledge with both your eyes and mind open. The learning and knowledge that we have, is, at the most, but little compared with that of which we are ignorant. True knowledge exists in knowing that you know nothing. And in knowing that you know nothing, that makes you the smartest of all. Plato Socrates Readers are advised to use the API documentation for the Java programming language as much as possible while using this book. The Java API documentation is where you will find a complete list of everything available in the Java class library. You can download (or view) the Java API documentation from the official website of Oracle Corporation at While you read this book, you need to practice writing Java programs yourself. You can also practice by tweaking the programs provided in the book. It does not help much in your learning process if you just read this book and do not practice by writing your own programs. Remember that practice makes perfect, which is also true in learning how to program in Java. Source Code and Errata Source code for this book can be accessed by clicking the Download Source Code button located at Questions and Comments Please direct all your questions and comments for the author to ksharan@jdojo.com. xxv