Java Cookbook

896 Pages·2014·14.105 MB·English

by  Ian F. Darwin

THIRD EDITION
Java Cookbook
Ian F. Darwin
Java Cookbook, Third Edition
by Ian F. Darwin
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June 2014: Third Edition
Revision History for the Third Edition:
2014-06-20: First release
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ISBN: 978-1-449-33704-9
[LSI]
Table of Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
1. Getting Started: Compiling, Running, and Debugging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1. Compiling and Running Java: JDK 2
1.2. Editing and Compiling with a Syntax-Highlighting Editor 3
1.3. Compiling, Running, and Testing with an IDE 4
1.4. Using CLASSPATH Effectively 14
1.5. Downloading and Using the Code Examples 17
1.6. Automating Compilation with Apache Ant 22
1.7. Automating Dependencies, Compilation, Testing, and Deployment with
Apache Maven 25
1.8. Automating Dependencies, Compilation, Testing, and Deployment with
Gradle 29
1.9. Dealing with Deprecation Warnings 31
1.10. Conditional Debugging Without #ifdef 33
1.11. Maintaining Program Correctness with Assertions 35
1.12. Debugging with JDB 36
1.13. Avoiding the Need for Debuggers with Unit Testing 38
1.14. Maintaining Your Code with Continuous Integration 41
1.15. Getting Readable Tracebacks 45
1.16. Finding More Java Source Code: Programs, Frameworks, Libraries 46
2. Interacting with the Environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
2.1. Getting Environment Variables 51
2.2. Getting Information from System Properties 52
2.3. Learning About the Current JDK Release 54
2.4. Dealing with Operating System–Dependent Variations 55
2.5. Using Extensions or Other Packaged APIs 58
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2.6. Parsing Command-Line Arguments 59
3. Strings and Things. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.1. Taking Strings Apart with Substrings 69
3.2. Breaking Strings Into Words 70
3.3. Putting Strings Together with StringBuilder 74
3.4. Processing a String One Character at a Time 76
3.5. Aligning Strings 78
3.6. Converting Between Unicode Characters and Strings 81
3.7. Reversing a String by Word or by Character 83
3.8. Expanding and Compressing Tabs 84
3.9. Controlling Case 89
3.10. Indenting Text Documents 90
3.11. Entering Nonprintable Characters 91
3.12. Trimming Blanks from the End of a String 92
3.13. Parsing Comma-Separated Data 93
3.14. Program: A Simple Text Formatter 98
3.15. Program: Soundex Name Comparisons 100
4. Pattern Matching with Regular Expressions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4.1. Regular Expression Syntax 107
4.2. Using regexes in Java: Test for a Pattern 114
4.3. Finding the Matching Text 117
4.4. Replacing the Matched Text 120
4.5. Printing All Occurrences of a Pattern 121
4.6. Printing Lines Containing a Pattern 123
4.7. Controlling Case in Regular Expressions 125
4.8. Matching “Accented” or Composite Characters 126
4.9. Matching Newlines in Text 127
4.10. Program: Apache Logfile Parsing 129
4.11. Program: Data Mining 131
4.12. Program: Full Grep 133
5. Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
5.1. Checking Whether a String Is a Valid Number 141
5.2. Storing a Larger Number in a Smaller Number 143
5.3. Converting Numbers to Objects and Vice Versa 144
5.4. Taking a Fraction of an Integer Without Using Floating Point 146
5.5. Ensuring the Accuracy of Floating-Point Numbers 147
5.6. Comparing Floating-Point Numbers 149
5.7. Rounding Floating-Point Numbers 151
5.8. Formatting Numbers 152
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5.9. Converting Between Binary, Octal, Decimal, and Hexadecimal 154
5.10. Operating on a Series of Integers 155
5.11. Working with Roman Numerals 157
5.12. Formatting with Correct Plurals 161
5.13. Generating Random Numbers 163
5.14. Calculating Trigonometric Functions 165
5.15. Taking Logarithms 166
5.16. Multiplying Matrices 167
5.17. Using Complex Numbers 169
5.18. Handling Very Large Numbers 171
5.19. Program: TempConverter 174
5.20. Program: Number Palindromes 175
6. Dates and Times—New API. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
6.1. Finding Today’s Date 182
6.2. Formatting Dates and Times 183
6.3. Converting Among Dates/Times, YMDHMS, and Epoch Seconds 185
6.4. Parsing Strings into Dates 186
6.5. Difference Between Two Dates 187
6.6. Adding to or Subtracting from a Date or Calendar 188
6.7. Interfacing with Legacy Date and Calendar Classes 189
7. Structuring Data with Java. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
7.1. Using Arrays for Data Structuring 192
7.2. Resizing an Array 193
7.3. The Collections Framework 195
7.4. Like an Array, but More Dynamic 196
7.5. Using Generic Collections 199
7.6. Avoid Casting by Using Generics 200
7.7. How Shall I Iterate Thee? Let Me Enumerate the Ways 204
7.8. Eschewing Duplicates with a Set 206
7.9. Using Iterators or Enumerations for Data-Independent Access 207
7.10. Structuring Data in a Linked List 208
7.11. Mapping with Hashtable and HashMap 212
7.12. Storing Strings in Properties and Preferences 214
7.13. Sorting a Collection 218
7.14. Avoiding the Urge to Sort 222
7.15. Finding an Object in a Collection 224
7.16. Converting a Collection to an Array 226
7.17. Rolling Your Own Iterator 227
7.18. Stack 230
7.19. Multidimensional Structures 234
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7.20. Program: Timing Comparisons 236
8. Object-Oriented Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.1. Formatting Objects for Printing with toString() 241
8.2. Overriding the equals() and hashCode() Methods 243
8.3. Using Shutdown Hooks for Application Cleanup 248
8.4. Using Inner Classes 250
8.5. Providing Callbacks via Interfaces 251
8.6. Polymorphism/Abstract Methods 255
8.7. Passing Values 256
8.8. Using Typesafe Enumerations 259
8.9. Enforcing the Singleton Pattern 263
8.10. Roll Your Own Exceptions 266
8.11. Using Dependency Injection 267
8.12. Program: Plotter 270
9. Functional Programming Techniques: Functional Interfaces, Streams,
Parallel Collections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
9.1. Using Lambdas/Closures Instead of Inner Classes 278
9.2. Using Lambda Predefined Interfaces Instead of Your Own 282
9.3. Simplifying Processing with Streams 283
9.4. Improving Throughput with Parallel Streams and Collections 285
9.5. Creating Your Own Functional Interfaces 286
9.6. Using Existing Code as Functional with Method References 289
9.7. Java Mixins: Mixing in Methods 293
10. Input and Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
10.1. Reading Standard Input 298
10.2. Reading from the Console or Controlling Terminal; Reading Passwords
Without Echoing 300
10.3. Writing Standard Output or Standard Error 302
10.4. Printing with Formatter and printf 304
10.5. Scanning Input with StreamTokenizer 308
10.6. Scanning Input with the Scanner Class 312
10.7. Scanning Input with Grammatical Structure 316
10.8. Opening a File by Name 317
10.9. Copying a File 318
10.10. Reading a File into a String 325
10.11. Reassigning the Standard Streams 325
10.12. Duplicating a Stream as It Is Written 326
10.13. Reading/Writing a Different Character Set 329
10.14. Those Pesky End-of-Line Characters 330
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10.15. Beware Platform-Dependent File Code 331
10.16. Reading “Continued” Lines 332
10.17. Reading/Writing Binary Data 336
10.18. Seeking to a Position within a File 337
10.19. Writing Data Streams from C 338
10.20. Saving and Restoring Java Objects 340
10.21. Preventing ClassCastExceptions with SerialVersionUID 344
10.22. Reading and Writing JAR or ZIP Archives 346
10.23. Finding Files in a Filesystem-Neutral Way with getResource() and
getResourceAsStream() 349
10.24. Reading and Writing Compressed Files 351
10.25. Learning about the Communications API for Serial and Parallel Ports 352
10.26. Save User Data to Disk 357
10.27. Program: Text to PostScript 360
11. Directory and Filesystem Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
11.1. Getting File Information 365
11.2. Creating a File 368
11.3. Renaming a File 369
11.4. Deleting a File 370
11.5. Creating a Transient File 372
11.6. Changing File Attributes 373
11.7. Listing a Directory 375
11.8. Getting the Directory Roots 377
11.9. Creating New Directories 378
11.10. Using Path instead of File 379
11.11. Using the FileWatcher Service to Get Notified about File Changes 380
11.12. Program: Find 382
12. Media: Graphics, Audio, Video. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
12.1. Painting with a Graphics Object 388
12.2. Showing Graphical Components Without Writing Main 389
12.3. Drawing Text 390
12.4. Drawing Centered Text in a Component 391
12.5. Drawing a Drop Shadow 393
12.6. Drawing Text with 2D 395
12.7. Drawing Text with an Application Font 397
12.8. Drawing an Image 400
12.9. Reading and Writing Images with javax.imageio 404
12.10. Playing an Audio/Sound File 405
12.11. Playing a Video File 406
12.12. Printing in Java 411
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12.13. Program: PlotterAWT 415
12.14. Program: Grapher 417
13. Network Clients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421
13.1. Contacting a Server 423
13.2. Finding and Reporting Network Addresses 424
13.3. Handling Network Errors 426
13.4. Reading and Writing Textual Data 427
13.5. Reading and Writing Binary Data 430
13.6. Reading and Writing Serialized Data 432
13.7. UDP Datagrams 433
13.8. Program: TFTP UDP Client 436
13.9. URI, URL, or URN? 441
13.10. REST Web Service Client 442
13.11. SOAP Web Service Client 444
13.12. Program: Telnet Client 448
13.13. Program: Chat Client 450
13.14. Program: Simple HTTP Link Checker 454
14. Graphical User Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457
14.1. Displaying GUI Components 458
14.2. Run Your GUI on the Event Dispatching Thread 460
14.3. Designing a Window Layout 462
14.4. A Tabbed View of Life 464
14.5. Action Handling: Making Buttons Work 465
14.6. Action Handling Using Anonymous Inner Classes 467
14.7. Action Handling Using Lambdas 469
14.8. Terminating a Program with “Window Close” 470
14.9. Dialogs: When Later Just Won’t Do 475
14.10. Catching and Formatting GUI Exceptions 477
14.11. Getting Program Output into a Window 480
14.12. Choosing a Value with JSpinner 486
14.13. Choosing a File with JFileChooser 487
14.14. Choosing a Color 489
14.15. Formatting JComponents with HTML 492
14.16. Centering a Main Window 493
14.17. Changing a Swing Program’s Look and Feel 496
14.18. Enhancing Your Swing GUI for Mac OS X 500
14.19. Building Your GUI Application with JavaFX 503
14.20. Program: Custom Font Chooser 505
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