임의의 생년월일 생성

임의의 생년월일 생성

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Java 프로그램을 사용하여 데이터베이스에있는 사람들의 생년월일을 무작위로 생성하려고합니다. 어떻게해야합니까?

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import java.util.GregorianCalendar;

public class RandomDateOfBirth {

    public static void main(String[] args) {

        GregorianCalendar gc = new GregorianCalendar();

        int year = randBetween(1900, 2010);

        gc.set(gc.YEAR, year);

        int dayOfYear = randBetween(1, gc.getActualMaximum(gc.DAY_OF_YEAR));

        gc.set(gc.DAY_OF_YEAR, dayOfYear);

        System.out.println(gc.get(gc.YEAR) + "-" + (gc.get(gc.MONTH) + 1) + "-" + gc.get(gc.DAY_OF_MONTH));

    }

    public static int randBetween(int start, int end) {
        return start + (int)Math.round(Math.random() * (end - start));
    }
}

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java.util.Date이 생성자 대기원 밀리 세컨드를 받아들이고, java.util.Random이 방법 당신에게 밀리 초 임의의 숫자를 줄 수 있습니다. 원하는 DOB 범위에 따라 임의 값의 범위를 설정하고 싶지만 그렇게해야합니다.

아주 대략 :

Random  rnd;
Date    dt;
long    ms;

// Get a new random instance, seeded from the clock
rnd = new Random();

// Get an Epoch value roughly between 1940 and 2010
// -946771200000L = January 1, 1940
// Add up to 70 years to it (using modulus on the next long)
ms = -946771200000L + (Math.abs(rnd.nextLong()) % (70L * 365 * 24 * 60 * 60 * 1000));

// Construct a date
dt = new Date(ms);

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Java 8 기반 솔루션 용 스 니펫 :

Random random = new Random();
int minDay = (int) LocalDate.of(1900, 1, 1).toEpochDay();
int maxDay = (int) LocalDate.of(2015, 1, 1).toEpochDay();
long randomDay = minDay + random.nextInt(maxDay - minDay);

LocalDate randomBirthDate = LocalDate.ofEpochDay(randomDay);

System.out.println(randomBirthDate);

참고 : 1900 년 1 월 (포함)에서 2015 년 1 월 1 일 (제외) 사이의 임의 날짜를 생성합니다.

참고 : EPOCH 날짜 , 즉 1970 년 1 월 1 일 ( EPOCH )에 상대적인 날짜를 기준으로합니다. EPOCH 이후의 긍정적 인 의미, EPOCH 이전의 부정적인 의미

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작은 유틸리티 클래스를 만들 수도 있습니다.

public class RandomDate {
    private final LocalDate minDate;
    private final LocalDate maxDate;
    private final Random random;

    public RandomDate(LocalDate minDate, LocalDate maxDate) {
        this.minDate = minDate;
        this.maxDate = maxDate;
        this.random = new Random();
    }

    public LocalDate nextDate() {
        int minDay = (int) minDate.toEpochDay();
        int maxDay = (int) maxDate.toEpochDay();
        long randomDay = minDay + random.nextInt(maxDay - minDay);
        return LocalDate.ofEpochDay(randomDay);
    }

    @Override
    public String toString() {
        return "RandomDate{" +
                "maxDate=" + maxDate +
                ", minDate=" + minDate +
                '}';
    }
}

다음과 같이 사용하십시오.

RandomDate rd = new RandomDate(LocalDate.of(1900, 1, 1), LocalDate.of(2010, 1, 1));
System.out.println(rd.nextDate());
System.out.println(rd.nextDate()); // birthdays ad infinitum

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임의의 날짜를 정의해야합니다. 그렇죠?

이를 수행하는 간단한 방법은 Datea long( 1970 년 1 월 1 일 이후의 시간 (밀리 초 ))를 사용하여 새 객체 를 생성 하고 임의의 값을 빼는 것입니다 long.

new Date(Math.abs(System.currentTimeMillis() - RandomUtils.nextLong()));

( RandomUtils 는 Apache Commons Lang에서 가져 왔습니다.)

물론 이것은 실제 임의의 날짜는 아니지만 (예를 들어 1970 년 이전에 날짜를 얻지 못할 것입니다), 당신의 필요에 충분할 것이라고 생각합니다.

그렇지 않으면 Calendarclass 를 사용하여 자신의 날짜를 만들 수 있습니다 .

int year = // generate a year between 1900 and 2010;
int dayOfYear = // generate a number between 1 and 365 (or 366 if you need to handle leap year);
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, randomYear);
calendar.set(Calendar.DAY_OF_YEAR, dayOfYear);
Date randomDoB = calendar.getTime();

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Java8의 경우-> 출생 데이터가 오늘 이전이어야한다고 가정합니다.

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Period;
import java.time.temporal.ChronoUnit;
import java.util.Random;

public class RandomDate {

    public static LocalDate randomBirthday() {
        return LocalDate.now().minus(Period.ofDays((new Random().nextInt(365 * 70))));
    }

    public static void main(String[] args) {
        System.out.println("randomDate: " + randomBirthday());
    }
}

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코드에 새 라이브러리를 추가하는 데 신경 쓰지 않는다면 MockNeat 를 사용할 수 있습니다 (면책 조항 : 저자 중 한 명입니다).

MockNeat mock = MockNeat.threadLocal();

// Generates a random date between [1970-1-1, NOW)
LocalDate localDate = mock.localDates().val();
System.out.println(localDate);

// Generates a random date in the past
// but beore 1987-1-30
LocalDate min = LocalDate.of(1987, 1, 30);
LocalDate past = mock.localDates().past(min).val();
System.out.println(past);

LocalDate max = LocalDate.of(2020, 1, 1);
LocalDate future = mock.localDates().future(max).val();
System.out.println(future);

// Generates a random date between 1989-1-1 and 1993-1-1
LocalDate start = LocalDate.of(1989, 1, 1);
LocalDate stop = LocalDate.of(1993, 1, 1);
LocalDate between = mock.localDates().between(start, stop).val();
System.out.println(between);

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임의의 생년월일 생성 :

import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    for (int i = 0; i < 100; i++) {
        System.out.println(randomDOB());
    }
  }

  public static String randomDOB() {

    int yyyy = random(1900, 2013);
    int mm = random(1, 12);
    int dd = 0; // will set it later depending on year and month

    switch(mm) {
      case 2:
        if (isLeapYear(yyyy)) {
          dd = random(1, 29);
        } else {
          dd = random(1, 28);
        }
        break;

      case 1:
      case 3:
      case 5:
      case 7:
      case 8:
      case 10:
      case 12:
        dd = random(1, 31);
        break;

      default:
        dd = random(1, 30);
      break;
    }

    String year = Integer.toString(yyyy);
    String month = Integer.toString(mm);
    String day = Integer.toString(dd);

    if (mm < 10) {
        month = "0" + mm;
    }

    if (dd < 10) {
        day = "0" + dd;
    }

    return day + '/' + month + '/' + year;
  }

  public static int random(int lowerBound, int upperBound) {
    return (lowerBound + (int) Math.round(Math.random()
            * (upperBound - lowerBound)));
  }

  public static boolean isLeapYear(int year) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    int noOfDays = calendar.getActualMaximum(Calendar.DAY_OF_YEAR);

    if (noOfDays > 365) {
        return true;
    }

    return false;
  }
}

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You can checkout randomizer for random data generation.This library helps to create random data from given Model class.Checkout below example code.

public class Person {

    @DateValue( from = "01 Jan 1990",to = "31 Dec 2002" , customFormat = "dd MMM yyyy")
    String dateOfBirth;

}

//Generate random 100 Person(Model Class) object 
Generator<Person> generator = new Generator<>(Person.class);  
List<Person> persons = generator.generate(100);                          

As there are many built in data generator is accessible using annotation,You also can build custom data generator.I suggest you to go through documentation provided on library page.

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Look this method:

public static Date dateRandom(int initialYear, int lastYear) {
    if (initialYear > lastYear) {
        int year = lastYear;
        lastYear = initialYear;
        initialYear = year;
    }

    Calendar cInitialYear = Calendar.getInstance();
    cInitialYear.set(Calendar.YEAR, 2015);
    long offset = cInitialYear.getTimeInMillis();

    Calendar cLastYear = Calendar.getInstance();
    cLastYear.set(Calendar.YEAR, 2016);
    long end = cLastYear.getTimeInMillis();

    long diff = end - offset + 1;
    Timestamp timestamp = new Timestamp(offset + (long) (Math.random() * diff));
    return new Date(timestamp.getTime());
}

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I think this will do the trick:

public static void main(String[] args) {
    Date now = new Date();
    long sixMonthsAgo = (now.getTime() - 15552000000l);
    long today = now.getTime();

    for(int i=0; i<10; i++) {
        long ms = ThreadLocalRandom.current().nextLong(sixMonthsAgo, today);

        Date date = new Date(ms);

        System.out.println(date.toString());
    }

}

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If you don't mind a 3rd party library, the Utils library has a RandomDateUtils that generates random java.util.Dates and all the dates, times, instants, and durations from Java 8's date and time API

LocalDate birthDate = RandomDateUtils.randomPastLocalDate();
LocalDate today = LocalDate.now();
LocalDate under18YearsOld = RandomDateUtils.randomLocalDate(today.minus(18, YEARS), today);
LocalDate over18YearsOld = RandomDateUtils.randomLocalDateBefore(today.minus(18, YEARS));

It is in the Maven Central Repository at:

<dependency>
  <groupId>com.github.rkumsher</groupId>
  <artifactId>utils</artifactId>
  <version>1.3</version>
</dependency>

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simplest method:

public static LocalDate randomDateOfBirth() {
    final int maxAge = 100 * 12 * 31;
    return LocalDate.now().minusDays(new Random().nextInt(maxAge));
}

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I am studying Scala and ended up Googling Java solutions for choosing a random date between range. I found this post super helpful and this is my final solution. Hope it can help future Scala and Java programmers.

import java.sql.Timestamp

def date_rand(ts_start_str:String = "2012-01-01 00:00:00", ts_end_str:String = "2015-01-01 00:00:00"): String = {
    val ts_start = Timestamp.valueOf(ts_start_str).getTime()
    val ts_end = Timestamp.valueOf(ts_end_str).getTime()
    val diff = ts_end - ts_start
    println(diff)
    val ts_rand = new Timestamp(ts_start + (Random.nextFloat() * diff).toLong)
    return ts_rand.toString
}                                         //> date_rand: (ts_start_str: String, ts_end_str: String)String

println(date_rand())                      //> 94694400000
                                              //| 2012-10-28 18:21:13.216

println(date_rand("2001-01-01 00:00:00", "2001-01-01 00:00:00"))
                                              //> 0
                                              //| 2001-01-01 00:00:00.0
println(date_rand("2001-01-01 00:00:00", "2010-01-01 00:00:00"))
                                              //> 283996800000
                                              //| 2008-02-16 23:15:48.864                    //> 2013-12-21 08:32:16.384

참고URL : https://stackoverflow.com/questions/3985392/generate-random-date-of-birth