Java'da Bazı Varyasyonlarla Rastgele Sayı Nasıl Üretilir?

Yayınlanan: 2019-02-27
rastgele sayı kırma

Java'da, Math sınıfında 0.0 and 1.0 arasında bir çift değer döndüren bir random() yöntemi vardır. Random sınıfında, 0 (dahil) ve n (hariç) aralığında rastgele bir değer döndüren nextInt(int n) yöntemi vardır.

Eminim geçmişte aşağıdaki sorularla karşılaşmışsınızdır:

  • Java'da rastgele sayılar nasıl oluşturulur?
  • Java ile bir aralıkta rasgele sayı üretme
  • Java Rastgele Sayı Örneklerini nerede bulabilirim?
  • Java.lang.Math.random() Yöntem Örneği

İşte Random() işlevini kullanan ve tüm sorularınıza cevap veren basit bir örnek.

Java'da Bazı Varyasyonlarla Rastgele Sayı Nasıl Üretilir?

Burada yaptığımız şey şu:

  • Minimum ve maksimum sayı arasında rastgele sayı yazdıran basit bir test olan RandomTest1 () yöntemini oluşturun (Sayı Aralığı Örneği).
  • Listeden rastgele giriş yazdıran basit bir test olan RandomTest2 () yöntemini oluşturun.
  • Main'de Two Threads oluşturun ve Main metodunu run .
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package crunchify . com . tutorials ;
 
import java . util . ArrayList ;
import java . util . List ;
import java . util . Random ;
 
/**
* @author Crunchify.com
* How to Generate Random Number in Java with Some Variations?
*/
 
public class CrunchifyRandomNumber {
 
     // Simple test which prints random number between min and max number (Number Range Example)
     public void RandomTest1 ( ) throws InterruptedException {
         while ( true ) {
             int min = 50 ;
             int max = 100 ;
 
             // random() returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0.
// Returned values are chosen pseudorandomly with (approximately) uniform distribution from that range.
             float randomNumber = ( min + ( float ) ( Math . random ( ) * ( ( max - min ) ) ) ) ;
             System . out . println ( "Crunchify Thread 1 random result: " + randomNumber ) ;
 
             // sleep() causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds,
             // subject to the precision and accuracy of system timers and schedulers.
             // The thread does not lose ownership of any monitors.
             Thread . sleep ( 500 ) ;
         }
     }
 
     // Simple test which prints random entry from list below
     public void RandomTest2 ( ) throws InterruptedException {
         List < String > list = new ArrayList < String > ( ) ;
         list . add ( "Facebook" ) ;
         list . add ( "Twitter" ) ;
         list . add ( "Google" ) ;
 
         Random randomNumber = new Random ( ) ;
         String randomEle ;
         int listSize = list . size ( ) ;
 
         while ( true ) {
             randomEle = list . get ( randomNumber . nextInt ( listSize ) ) ;
             System . out . println ( "Crunchify Thread 2 random result: " + randomEle ) ;
             Thread . sleep ( 500 ) ;
         }
     }
 
     static public void main ( String [ ] args ) {
 
         // Let's run both Test1 and Test2 methods in parallel..
         Thread crunchifyThread1 = new Thread ( ) {
             public void run ( ) {
                 CrunchifyRandomNumber crNumber = new CrunchifyRandomNumber ( ) ;
                 try {
                     crNumber . RandomTest1 ( ) ;
                 } catch ( InterruptedException e ) {
                     e . printStackTrace ( ) ;
                 }
             }
         } ;
         Thread crunchifyThread2 = new Thread ( ) {
             public void run ( ) {
                 CrunchifyRandomNumber crNumber = new CrunchifyRandomNumber ( ) ;
                 try {
                     crNumber . RandomTest2 ( ) ;
                 } catch ( InterruptedException e ) {
                     e . printStackTrace ( ) ;
                 }
             }
         } ;
 
         // start() Causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread.
//The result is that two threads are running concurrently: the current thread
// (which returns from the call to the start method) and the other thread (which executes its run method).
         crunchifyThread1 . start ( ) ;
         crunchifyThread2 . start ( ) ;
     }
 
}
 

Eclipse Konsol Çıktısı:

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/ Library / Java / JavaVirtualMachines / jdk - 15.jdk / Contents / Home / bin / java - javaagent : / Applications / IntelliJ IDEA . app / Contents / lib / idea_rt . jar = 55975 : / Applications / IntelliJ IDEA . app / Contents / bin - Dfile . encoding = UTF - 8 - classpath / Users / app / crunchify / github / CrunchifyTutorials / target / classes : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / zxing - 2.1.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - logging - 1.1.2.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - collections - 3.2.1.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / javax . mail . jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - io - 2.4.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - 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4.12.jar : / Users / app / . m2 / repository / org / hamcrest / hamcrest - core / 1.3 / hamcrest - core - 1.3.jar : / Users / app / . m2 / repository / ch / qos / logback / logback - classic / 1.2.3 / logback - classic - 1.2.3.jar : / Users / app / . m2 / repository / ch / qos / logback / logback - core / 1.2.3 / logback - core - 1.2.3.jar : / Users / app / . m2 / repository / org / springframework / spring - context / 5.1.3.RELEASE / spring - context - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - aop / 5.1.3.RELEASE / spring - aop - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - beans / 5.1.3.RELEASE / spring - beans - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - core / 5.1.3.RELEASE / spring - core - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - jcl / 5.1.3.RELEASE / spring - jcl - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - expression / 5.1.3.RELEASE / spring - expression - 5.1.3.RELEASE.jar : / Users / app / . m2 / repository / org / springframework / spring - context - support / 5.1.3.RELEASE / spring - context - support - 5.1.3.RELEASE.jar crunchify . com . tutorials . CrunchifyRandomNumber
Crunchify Thread 2 random result : Twitter
Crunchify Thread 1 random result : 98.03486
Crunchify Thread 2 random result : Google
Crunchify Thread 1 random result : 57.48709
Crunchify Thread 2 random result : Google
Crunchify Thread 1 random result : 87.54976
Crunchify Thread 2 random result : Google
Crunchify Thread 1 random result : 75.2223
Crunchify Thread 2 random result : Facebook
Crunchify Thread 1 random result : 91.617584
Crunchify Thread 2 random result : Facebook
Crunchify Thread 1 random result : 64.705574
Crunchify Thread 2 random result : Google
Crunchify Thread 1 random result : 72.043884
Crunchify Thread 2 random result : Google
Crunchify Thread 1 random result : 70.38615
Crunchify Thread 2 random result : Facebook
Crunchify Thread 1 random result : 55.705227
Crunchify Thread 2 random result : Facebook
Crunchify Thread 1 random result : 76.36104
Crunchify Thread 2 random result : Twitter
Crunchify Thread 1 random result : 75.84907
 
Process finished with exit code 130 ( interrupted by signal 2 : SIGINT )
 

Java ile ilgili 500'den fazla öğreticiye göz atmak isteyebilirsiniz.