代码整洁之道 英文版PDF电子书下载

Chapter 1:Clean Code 1

There Will Be Code 2

Bad Code 3

The Total Cost of Owning a Mess 4

The Grand Redesign in the Sky 5

Attitude 5

The Primal Conundrum 6

The Art of Clean Code? 6

What Is Clean Code? 7

Schools of Thought 12

We Are Authors 13

The Boy Scout Rule 14

Prequel and Principles 15

Conclusion 15

Bibliography 15

Chapter 2:Meaningful Names 17

Introduction 17

Use Intention-Revealing Names 18

Avoid Disinformation 19

Make Meaningful Distinctions 20

Use Pronounceable Names 21

Use Searchable Names 22

Avoid Encodings 23

Hungarian Notation 23

Member Prefixes 24

Interfaces and Implementations 24

Avoid Mental Mapping 25

Class Names 25

Method Names 25

Don't Be Cute 26

Pick One Word per Concept 26

Don't Pun 26

Use Solution Domain Names 27

Use Problem Domain Names 27

Add Meaningful Context 27

Don't Add Gratuitous Context 29

Final Words 30

Chapter 3:Functions 31

Small! 34

Blocks and Indenting 35

Do One Thing 35

Sections within Functions 36

One Level of Abstraction per Function 36

Reading Code from Top to Bottom:The Stepdown Rule 37

Switch Statements 37

Use Descriptive Names 39

Function Arguments 40

Common Monadic Forms 41

Flag Arguments 41

Dyadic Functions 42

Triads 42

Argument Objects 43

Argument Lists 43

Verbs and Keywords 43

Have No Side Effects 44

Output Arguments 45

Command Query Separation 45

Prefer Exceptions to Returning Error Codes 46

Extract Try/Catch Blocks 46

Error Handling Is One Thing 47

The Error.java Dependency Magnet 47

Don't Repeat Yourself 48

Structured Programming 48

How Do You Write Functions Like This? 49

Conclusion 49

SetupTeardownIncluder 50

Bibliography 52

Chapter 4:Comments 53

Comments Do Not Make Up for Bad Code 55

Explain Yourself in Code 55

Good Comments 55

Legal Comments 55

Informative Comments 56

Explanation of Intent 56

Clarification 57

Warning of Consequences 58

TODO Comments 58

Amplification 59

Javadocs in Public APIs 59

Bad Comments 59

Mumbling 59

Redundant Comments 60

Misleading Comments 63

Mandated Comments 63

Journal Comments 63

Noise Comments 64

Scary Noise 66

Don't Use a Comment When You Can Use a Function or a Variable 67

Position Markers 67

Closing Brace Comments 67

Attributions and Bylines 68

Commented-Out Code 68

HTML Comments 69

Nonlocal Information 69

Too Much Information 70

Inobvious Connection 70

Function Headers 70

Javadocs in Nonpublic Code 71

Example 71

Bibliography 74

Chapter 5:Formatting 75

The Purpose of Formatting 76

Vertical Formatting 76

The Newspaper Metaphor 77

Vertical Openness Between Concepts 78

Vertical Density 79

Vertical Distance 80

Vertical Ordering 84

Horizontal Formatting 85

Horizontal Openness and Density 86

Horizontal Alignment 87

Indentation 88

Dummy Scopes 90

Team Rules 90

Uncle Bob's Formatting Rules 90

Chapter 6:Objects and Data Structures 93

Data Abstraction 93

Data/Object Anti-Symmetry 95

The Law of Demeter 97

Train Wrecks 98

Hybrids 99

Hiding Structure 99

Data Transfer Objects 100

Active Record 101

Conclusion 101

Bibliography 101

Chapter 7:Error Handling 103

Use Exceptions Rather Than Return Codes 104

Write Your Try-Catch-Finally Statement First 105

Use Unchecked Exceptions 106

Provide Context with Exceptions 107

Define Exception Classes in Terms of a Caller's Needs 107

Define the Normal Flow 109

Don't Return Null 110

Don't Pass Null 111

Conclusion 112

Bibliography 112

Chapter 8:Boundaries 113

Using Third-Party Code 114

Exploring and Learning Boundaries 116

Learning log4j 116

Learning Tests Are Better Than Free 118

Using Code That Does Not Yet Exist 118

Clean Boundaries 120

Bibliography 120

Chapter 9:Unit Tests 121

The Three Laws of TDD 122

Keeping Tests Clean 123

Tests Enable the -ilities 124

Clean Tests 124

Domain-Specific Testing Language 127

A Dual Standard 127

One Assert per Test 130

Single Concept per Test 131

F.I.R.S.T 132

Conclusion 133

Bibliography 133

Chapter 10:Classes 135

Class Organization 136

Encapsulation 136

Classes Should Be Small! 136

The Single Responsibility Principle 138

Cohesion 140

Maintaining Cohesion Results in Many Small Classes 141

Organizing for Change 147

Isolating from Change 149

Bibliography 151

Chapter 11:Systems 153

How Would You Build a City? 154

Separate Constructing a System from Using It 154

Separation of Main 155

Factories 155

Dependency Injection 157

Scaling Up 157

Cross-Cutting Concerns 160

Java Proxies 161

Pure Java AOP Frameworks 163

AspectJ Aspects 166

Test Drive the System Architecture 166

Optimize Decision Making 167

Use Standards Wisely,When They Add Demonstrable Value 168

Systems Need Domain-Specific Languages 168

Conclusion 169

Bibliography 169

Chapter 12:Emergence 171

Getting Clean via Emergent Design 171

Simple Design Rule 1:Runs All the Tests 172

Simple Design Rules 2-4:Refactoring 172

No Duplication 173

Expressive 175

Minimal Classes and Methods 176

Conclusion 176

Bibliography 176

Chapter 13:Concurrency 177

Why Concurrency? 178

Myths and Misconceptions 179

Challenges 180

Concurrency Defense Principles 180

Single Responsibility Principle 181

Corollary:Limit the Scope of Data 181

Corollary:Use Copies of Data 181

Corollary:Threads Should Be as Independent as Possible 182

Know Your Library 182

Thread-Safe Collections 182

Know Your Execution Models 183

Producer-Consumer 184

Readers-Writers 184

Dining Philosophers 184

Beware Dependencies Between Synchronized Methods 185

Keep Synchronized Sections Small 185

Writing Correct Shut-Down Code Is Hard 186

Testing Threaded Code 186

Treat Spurious Failures as Candidate Threading Issues 187

Get Your Nonthreaded Code Working First 187

Make Your Threaded Code Pluggable 187

Make Your Threaded Code Tunable 187

Run with More Threads Than Processors 188

Run on Different Platforms 188

Instrument Your Code to Try and Force Failures 188

Hand-Coded 189

Automated 189

Conclusion 190

Bibliography 191

Chapter 14:Successive Refinement 193

Args Implementation 194

How Did I Do This? 200

Args:The Rough Draft 201

So I Stopped 212

On Incrementalism 212

String Arguments 214

Conclusion 250

Chapter 15:JUnit Internals 251

The JUnit Framework 252

Conclusion 265

Chapter 16:Refactoring SerialDate 267

First,Make It Work 268

Then Make It Right 270

Conclusion 284

Bibliography 284

Chapter 17:Smells and Heuristics 285

Comments 286

C1:Inappropriate Information 286

C2:Obsolete Comment 286

C3:Redundant Comment 286

C4:Poorly Written Comment 287

C5:Commented-Out Code 287

Environment 287

E1:Build Requires More Than One Step 287

E2:Tests Require More Than One Step 287

Functions 288

F1:Too Many Arguments 288

F2:Output Arguments 288

F3:Flag Arguments 288

F4:Dead Function 288

General 288

G1:Multiple Languages in One Source File 288

G2:Obvious Behavior Is Unimplemented 288

G3:Incorrect Behavior at the Boundaries 289

G4:Overridden Safeties 289

G5:Duplication 289

G6:Code at Wrong Level of Abstraction 290

G7:Base Classes Depending on Their Derivatives 291

G8:Too Much Information 291

G9:Dead Code 292

G10:Vertical Separation 292

G11:Inconsistency 292

G12:Clutter 293

G13:Artificial Coupling 293

G14:Feature Envy 293

G15:Selector Arguments 294

G16:Obscured Intent 295

G17:Misplaced Responsibility 295

G18:Inappropriate Static 296

G19:Use Explanatory Variables 296

G20:Function Names Should Say What They Do 297

G21:Understand the Algorithm 297

G22:Make Logical Dependencies Physical 298

G23:Prefer Polymorphism to If/Else or Switch/Case 299

G24:Follow Standard Conventions 299

G25:Replace Magic Numbers with Named Constants 300

G26:Be Precise 301

G27:Structure over Convention 301

G28:Encapsulate Conditionals 301

G29:Avoid Negative Conditionals 302

G30:Functions Should Do One Thing 302

G31:Hidden Temporal Couplings 302

G32:Don't Be Arbitrary 303

G33:Encapsulate Boundary Conditions 304

G34:Functions Should Descend Only One Level of Abstraction 304

G35:Keep Configurable Data at High Levels 306

G36:Avoid Transitive Navigation 306

Java 307

J1:Avoid Long Import Lists by Using Wildcards 307

J2:Don't Inherit Constants 307

J3:Constants versus Enums 308

Names 309

N1:Choose Descriptive Names 309

N2:Choose Names at the Appropriate Level of Abstraction 311

N3:Use Standard Nomenclature Where Possible 311

N4:Unambiguous Names 312

N5:Use Long Names for Long Scopes 312

N6:Avoid Encodings 312

N7:Names Should Describe Side-Effects 313

Tests 313

T1:Insufficient Tests 313

T2:Use a Coverage Tool! 313

T3:Don't Skip Trivial Tests 313

T4:An Ignored Test Is a Question about an Ambiguity 313

T5:Test Boundary Conditions 314

T6:Exhaustively Test Near Bugs 314

T7:Patterns of Failure Are Revealing 314

T8:Test Coverage Patterns Can Be Revealing 314

T9:Tests Should Be Fast 314

Conclusion 314

Bibliography 315

Appendix A:Concurrency Ⅱ 317

Client/Server Example 317

The Server 317

Adding Threading 319

Server Observations 319

Conclusion 321

Possible Paths of Execution 321

Number of Paths 322

Digging Deeper 323

Conclusion 326

Knowing Your Library 326

Executor Framework 326

Nonblocking Solutions 327

Nonthread-Safe Classes 328

Dependencies Between Methods Can Break Concurrent Code 329

Tolerate the Failure 330

Client-Based Locking 330

Server-Based Locking 332

Increasing Throughput 333

Single-Thread Calculation of Throughput 334

Multithread Calculation of Throughput 335

Deadlock 335

Mutual Exclusion 336

Lock＆Wait 337

No Preemption 337

Circular Wait 337

Breaking Mutual Exclusion 337

Breaking Lock＆Wait 338

Breaking Preemption 338

Breaking Circular Wait 338

Testing Multithreaded Code 339

Tool Support for Testing Thread-Based Code 342

Conclusion 342

Tutorial:Full Code Examples 343

Client/Server Nonthreaded 343

Client/Server Using Threads 346

Appendix B:org.jfree.date.SerialDate 349

Appendix C:Cross References of Heuristics 409

Epilogue 411

Index 413