[java] SecureRandomについてSeedが同じ場合に同じ番号が生成されるのか調べてみた

CreateRandomNumberTest.java

public class CreateRandomNumberTest{
  Logger LOGGER = LoggerFactory.getLogger(CreateRandomNumberTest.class);
	
	@Test
	public void testExpire(){
		List<Long> rundomList1 =new ArrayList<Long>();
		List<Long> rundomList2 =new ArrayList<Long>();

		SecureRandom rundom = new SecureRandom();
		
		// set list1
		rundom.setSeed(100);
		for(int i =0 ; i < 100 ; i++){
			rundomList1.add(rundom.nextLong());
		}
		// set list2
		rundom.setSeed(100);
		for(int i =0 ; i < 100 ; i++){
			rundomList2.add(rundom.nextLong());
		}

		for(int i =0 ; i < 100 ; i++){
			LOGGER.info("case {} ---- value is same? :{}", i, rundomList1.get(i) == rundomList2.get(i));
			if(rundomList1.get(i) == rundomList2.get(i)){
				LOGGER.info("value = {}", rundomList1.get(i));
			}else{
				LOGGER.info("value1 = {}", rundomList1.get(i));
				LOGGER.info("value2 = {}", rundomList2.get(i));
			}
		}
	}
}

result

2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:55) case 0 ---- value is same? :false
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:59) value1 = -2939792941618945998
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:60) value2 = -7727676554572007407
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:55) case 1 ---- value is same? :false
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:59) value1 = 5897670234144026358
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:60) value2 = 280358609247163950
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:55) case 2 ---- value is same? :false
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:59) value1 = -5525963336431927132
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:60) value2 = -1022068508836883298
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:55) case 3 ---- value is same? :false
2013-03-15 12:16:09 [INFO ](CreateSerialNumberTest:59) value1 = 2312409136815735309

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