JAVA Coding Pattern

JAVA Coding Pattern 코딩 규칙 2010.08.03 박혜웅

Code Conventions-Basic • 이 문서는 권고안의 내용중 중요한 부분과 개인경험을 통해 정리하였다. • Sun의 권고안 • http://java.sun.com/docs/codeconv/ • http://www.oracle.com/technetwork/java/codeconv-138413.html • 권고안을 따르는 Eclipse default formatter를 기준으로 한다.

Code Conventions • File Type • .java (UTF-8) • .class • README • 설명을 위한 텍스트 파일 (UTF-8) • Beginning Comments • ?? • Class and Interface Declarations • Variables, Method • public, protected, private 순서로 나열 • Indentation • tabs only (4 spaces), Eclipse default formatter와 동일 • Line Length • 80 ~ 150 (모니터에 맞게) • Wrapping Lines (줄 바꿈) • Eclipse default formatter 와 동일

Code Conventions-Comments • Block Comments, Single-Line comments, Trailing Comments (/* */) • Do not use for commenting code. • Search명령의 검색결과가 소스인지 코멘트인지 불분명하므로. • End-Of-Line Comments (//) • Use for commenting code. //if (bar > 1 ) { // // // To do: // ... //} // else // return false;

Code Conventions-Declarations • One declaration per line • Eclipse default formatter 와 동일 • Avoid declarations that hide declaratioins. • 동일한 변수명을 가능한 사용하지 말아라 • 단, Constructor, Setter, Getter는 예외다. int level; // Good int size; // Good int level, size; // Avoid int count; ... func() { if (...) { int countSome; ... int count; ... setCount(int count) { if (...) { this.count=count; ... int count; ... func() { if (condition) { int count;// Avoid ...

Code Conventions-Declarations • Class and Interface Declarations • Eclipse default formatter와 동일 • Methods are separated by blank line class Sample extends Object { int ivar1; int ivar2; Sample(int i, int j){ ivar1=i; ivar2=j; } int emptyMethod() {} ... }

Code Conventions-Statements • Simple Statements • Each line should contain at most one statement • Do not use the comma operator • return Statements • Use simple expression • Do not use ternary expression (?) argv++; argc--; argv++; argc--; // Avoid System.out.println("error"); System.exit(1); System.out.println("error"), System.exit(1);// Avoid return; return: myDisk.size(); if( size > 0 ) { return size; } return 0; return (size ? size : defaultSize); // Avoid

Code Conventions-Statements, Blank • if-else Statements • if statements always use braces {}. • for, while Statements • An empty for, whlie statement should have the following form • Blank Lines, Blank Spaces • Eclipse default formatter if ( condition ) { statement; } if ( condition ) // Avoid statement; for ( initialization; condition; update ); while ( condition ); for ( initialization; condition; update ) {} ; //Avoid while ( condition ) {}; //Avoid

Code Conventions-Naming • Java Project(?), Classes, Interfaces Naming • Should be noun with the first letter capitalized. • Avoid acronyms(머리글자어) and abbreviatioins(약어) except URL, HTML... • Example • class URLEncoder; • interface Storing; • Use Whole words. • Example • class MatrixCalculation; // OK • class MatCalc; // AVOID! • Methods • Should be verbs with the first letter lowercase. • Omit class or interface name. • Example • MatrixCalculation calculation = new MatrixCaculation(); • calculation.getData(); // OK • calculation.getMatrixCalculationData(); // AVOID!

Code Conventions-Naming • Variables • Should be noun with the first letter lowercase. • If instance variable(public, protected, private, default), always use keyword “this”. • Example • private long instanceVariable; • this.instanceVariable = 10L; // OK • instanceVariable = 10L; // AVOID! • Avoid acronyms(머리글자어) and abbreviatioins(약어) • Example • BufferedReader bufferedReader = new BufferedReader(); // OK • BufferedReader reader = new BufferedReader(); // OK • BufferedReader br = new BufferedReader(); //AVOID! • if name is so long, can be shortten. • Example • int difference; // OK • int diff; // OK • int d; // AVOID

Code Conventions-Naming • Constants (static final) • Should be all uppercase with words separated by underscores(_). • Ends with noun. • Example • static final int MIN_WIDTH = 4; // OK • static final int minWidth = 4; // AVOID!

Code Conventions-Programming • Referring to Class Variables and Methods • Avoid using an object to access a static variable or method. • Example • AClass.classMethod(); // OK • anObject.classMethod(); // AVOID! • Variable Assignments • Avoid assigning several variables to the same value in a single statement. • Example • fooBar.fChar = barFoo.lchar = ‘c’; //AVOID! • d = (a = b + c) + r; //AVOID! • Parenthese(소괄호) • Use parentheses liberally. • Example • if(a == b && c == d) //AVOID! • if((a ==b) && (c == d)) // OK

JAVA Coding Pattern