[JAVA] (조금 더 정확한)실행시간 확인, 측정하기(timer)

http://blog.opid.kr/334

실행환경
Notebook	SAMSUNG NT550p5c-s61r
CPU	Intel Core i5-3210M 2.50GHz
Memory	8 GB
OS	Window 7 ultimate 64bit
Java	1.7.0_51
Android	SDK : 4.4.2 (KitKat) / 테스트기기 : Galaxy S3 4.3 (Jelly Bean)
WebServer	Apache Tomcat 7.0

코드 실행시간 확인하기

조금 더 정확한 측정 방법

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public class TimerTest {     public static void main(String[] args) {           ExecTime timer = new ExecTime();         timer.start();           // code         for (int i = 0; i < 100000000; i++) {           }         timer.stop();           timer.printExecTime();         System.out.println(timer.getRunTimeNano() / 1000000 + " ms");         System.out.println(timer.getRunTimeNano() / 1000000 / 1000 + " sec");     }   }   class ExecTime {     private long start;     private long stop;       void start() {         start = System.nanoTime();     }       void stop() {         stop = System.nanoTime();     }       long getRunTimeNano() {         return stop - start;     }       void printExecTime() {         System.out.println(stop - start + " ns");     } }

방법1

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class TimeTest1 {     public static void main(String[] args) {           long startTime = System.currentTimeMillis();           // code           long stopTime = System.currentTimeMillis();         long runTime = stopTime - startTime;           System.out.println(runTime);     } }

방법 2

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public class Stopwatch {     long start;     long end;           void start() {         start = System.currentTimeMillis();     }           void stop() {         end = System.currentTimeMillis();     }           String getRunTime(){         return end - start + "";     } }

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class TimeTest2 {     public static void main(String[] args) {           Stopwatch timer = new Stopwatch().start();           // code           timer.stop();           System.out.println(timer.getRunTime());     } }