Go for Java Programmers: Learn the Google Go Programming Language

 Table of Contents....5 About the Author....12 About the Technical Reviewer....13 Acknowledgments....14 Introduction....15 Assessments....30 Part I: First Look at Go....31 Chapter 1: A Brief Look at Go vs. Java....34 Go Is a Compiled (vs. Interpreted, As Java Is) Language....35 Go and Java Share Similar Program Structure....36 Go and Java Have Some Code Style Differences That Influence How Code Is Structured....36 Both Go and Java Are Procedural Languages....37 Java Is an Object-Oriented (OO) Language, While Go Is Not Fully OO....38 Java Is a Highly Functional Language, Go Is Less So....39 Java Is a Highly Declarative Language, Go Is Less So....39 Many Java Features Are Annotation Driven....39 Go Does Not Support Exceptions....40 Both Java and Go Use Managed Memory (Garbage Collectors)....40 Go and Java Both Support Concurrency but in Different Ways....41 Go’s Runtime Is Simpler Than the JRE....41 The Go Program Build Process Is Different....42 Go and Java Have Similar Release Cycles....42 Chapter 2: What Java Has That Go Does Not....44 Multiple Assignments....44 Statements and Operators....44 Assert Statement....45 While and Do Statements....45 Throw Statement/Throws Clause....46 Strictfp, transient, volatile, synchronized, abstract, static....46 Objects and Classes (OOP) and Inner Classes, Lambdas, this, super, Explicit Constructors....46 Generic Types and Methods....49 Extensive Functional Programming Capabilities....49 Boxing of Primitive Values....50 Source Annotations....50 Multiple Visibilities....51 Overloaded/Overridden Functions....51 Formal Enums....51 Built-in Binary Data Self-Serialization....52 Concurrent Collections....52 Chapter 3: A Deeper Comparison of Go and Java....53 Part II: The Go Language....58 Chapter 4: Key Go Aspects....59 Simple Go Program Example....61 Go Packages....67 Go Comments....70 Go Build/Run Process....71 Go Playground....72 Go Integrated Development Environments....76 Running Go Programs....81 Building Go Programs....82 Bytecode vs. Real Code....85 Go Command-Line Tools....87 Tools Bundled in the Go Command....88 Other Tools....90 Go Runs Programs Instead of Classes....90 Go Memory Management....92 Go Identifiers....97 Go Scopes....99 Go Scopes vs. Go Source Files....102 Initializing Go Variables....104 Lifetimes of Go Identifiers....106 Go Module Summary....107 Go Assignments and Expressions....113 Text Formatting in Go....115 Goroutines....120 Issues with Concurrency....120 Go Concurrency....123 Goroutines by Example....126 Chapter 5: Go Basic Features....136 Language Keywords....136 Operators and Punctuation....139 Go Operator Precedence....144 Go Built-in Functions....145 Chapter 6: Go Types....147 Primitive/Built-in Types....147 Numbers....147 Characters and Strings....149 Reference vs. Pointer Types....150 Drill Down on Basic Data Types....153 Boolean Type....153 Integer Types....153 Floating-Point Types....154 When nil Can Go Wrong....155 Programmer-Defined Types....156 Arrays....161 Slices....163 Maps....168 Functions....171 Methods As Functions....176 Any Declared Type Can Have Custom Functions....177 Functions As Values....179 Structs....183 Structure Fields....186 Structure Literals....188 Nested Structures....189 Structure Field Alignment....191 Interfaces....192 Application of Interfaces....195 Composite Interfaces....198 Channels....199 Variable Declarations....203 Constant Declarations....206 Type Casting....208 Type Testing....209 Derived Type Declarations....212 Chapter 7: Errors and Panics....216 Go Errors....216 Go Panics....218 Errors and Panics Illustrated....222 Chapter 8: Go Statements....229 Package and Import Statements....230 Assignment Statements....231 Declaring Variables....233 Declaring Named Constants....235 If/Else Statements....236 Switch Statement....239 While Statement....242 Do-While Statement....243 For with Index Statement....243 For over a Collection Statement....244 Forever Statement....246 Break and Continue Statements....247 Goto Statement....248 Return Statement....249 Defer Statement....250 Go Statement....251 Select Statement....252 Chapter 9: Applications for Interfaces....254 An Interface Is the Key....254 On Dependency Injection....257 On Aspect-Oriented Programming....265 Chapter 10: Go Unit Tests and Benchmarks....270 Test Cases and Benchmarks in Go....271 Test Cases in Java....283 Chapter 11: Going into the Future....288 Improved Error Handling....288 Go Generics....290 Capstone Game of Life Example....296 Game of Life Go Source....301 Capstone Project in Java....302 Main.java....303 Server.java....310 Game.java....322 Utility.java....335 Formatter.java....336 ParameterProvider.java....340 AnnimatedGifWriter.java....341 Logger.java....344 Capstone Project in Go....347 Main.go....347 Server.go....352 Game.go....361 Utility.go....373 Go Doc Output....374 API Outputs....376 Game Outputs....380 Part III: Go Library Survey....383 Chapter 12: Key Package Comparison....395 Java Lang Packages....395 Java IO Package....400 Java Text Package....403 Java Time Packages....405 Java Util Packages....406 Chapter 13: Key Method/Function Comparison....413 Chapter 14: Go Package Survey....419 File Access with Go....419 Compression Services....422 Archive Packages....422 Compression Packages....425 Image....426 Input/Output (I/O)....429 Bytes Package....435 Format Package....439 Data Collections....441 Sorting....444 Context Package....446 Cryptography and Hashing and Data Encoding....450 Encoding Packages....451 Unicode Encoding Packages....453 Chapter 15: SQL Database Access....456 Chapter 16: Client and Server Support....467 MIME Packages....467 Network Packages....467 The Net Package....468 The HTTP Template Package....480 The Net.HTTP Package....485 URL Package....495 Chapter 17: Go Runtime....497 Errors Package....497 Flag Package....498 Log Package....503 Math Package....510 Operating System Support Packages....525 Reflection Package....533 Regular Expression Package....535 Go Runtime Packages....537 String Processing Packages....538 Concurrency and Goroutines....543 Testing Package....546 Time and Date Package....551 Appendix A: Installing Go....558 Appendix B: Some Go FAQs....569 Appendix C: Go Gotchas to Look Out For....577 Appendix D: Mark-Sweep Pseudocode....582 Appendix E: ASCII vs. UTF-8....586 Index....589