Package org.h2.test.synth.sql

Class RandomGen

java.lang.Object
org.h2.test.synth.sql.RandomGen
public class RandomGen extends Object
A random data generator class.

  • Constructor Details

    • RandomGen

      public RandomGen()
      Create a new random instance with a fixed seed value.

  • Method Details

    • getInt

      public int getInt(int max)
      Get the next integer that is smaller than max.
      Parameters:
      max - the upper limit (exclusive)
      Returns:
      the random value

    • nextGaussian

      public double nextGaussian()
      Get the next gaussian value.
      Returns:
      the value

    • getLog

      public int getLog(int max)
      Get the next random value that is at most max but probably much lower.
      Parameters:
      max - the maximum value
      Returns:
      the value

    • getBytes

      public void getBytes(byte[] data)
      Get a number of random bytes.
      Parameters:
      data - the target buffer

    • getBoolean

      public boolean getBoolean(int percent)
      Get a boolean that is true with the given probability in percent.
      Parameters:
      percent - the probability
      Returns:
      the boolean value

    • randomString

      public String randomString(int len)
      Get a random string with the given length.
      Parameters:
      len - the length
      Returns:
      the string

    • getRandomInt

      public int getRandomInt()
      Get a random integer. In 10% of the cases, Integer.MAX_VALUE is returned, in 10% of the cases Integer.MIN_VALUE. Also in the 10% of the cases, a random value between those extremes is returned. In 20% of the cases, this method returns 0. In 10% of the cases, a gaussian value in the range -200 and +1800 is returned. In all other cases, a gaussian value in the range -5 and +20 is returned.
      Returns:
      the random value

    • getRandomLong

      public long getRandomLong()
      Get a random long. The algorithm is similar to a random int.
      Returns:
      the random value

    • getRandomDouble

      public double getRandomDouble()
      Get a random double. The algorithm is similar to a random int.
      Returns:
      the random value

    • nextBoolean

      public boolean nextBoolean()
      Get a random boolean.
      Returns:
      the random value

    • getIntArray

      public int[] getIntArray()
      Get a random integer array. In 10% of the cases, null is returned.
      Returns:
      the array

    • getByteArray

      public byte[] getByteArray()
      Get a random byte array. In 10% of the cases, null is returned.
      Returns:
      the array

    • randomTime

      public Time randomTime()
      Get a random time value. In 10% of the cases, null is returned.
      Returns:
      the value

    • randomTimestamp

      public Timestamp randomTimestamp()
      Get a random timestamp value. In 10% of the cases, null is returned.
      Returns:
      the value

    • randomDate

      public Date randomDate()
      Get a random date value. In 10% of the cases, null is returned.
      Returns:
      the value

    • modify

      public String modify(String sql)
      Randomly modify a SQL statement.
      Parameters:
      sql - the original SQL statement
      Returns:
      the modified statement

    • setSeed

      public void setSeed(int seed)
      Set the seed value.
      Parameters:
      seed - the new seed value