Class RandomUtils
- java.lang.Object
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- org.apache.commons.lang3.RandomUtils
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public class RandomUtils extends java.lang.Object
Utility library that supplements the standard
Random
class.Caveat: Instances of
Random
are not cryptographically secure.Please note that the Apache Commons project provides a component dedicated to pseudo-random number generation, namely Commons RNG, that may be a better choice for applications with more stringent requirements (performance and/or correctness).
- Since:
- 3.3
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Constructor Summary
Constructors Constructor Description RandomUtils()
RandomUtils
instances should NOT be constructed in standard programming.
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static boolean
nextBoolean()
Returns a random boolean valuestatic byte[]
nextBytes(int count)
Creates an array of random bytes.static double
nextDouble()
Returns a random double within 0 - Double.MAX_VALUEstatic double
nextDouble(double startInclusive, double endExclusive)
Returns a random double within the specified range.static float
nextFloat()
Returns a random float within 0 - Float.MAX_VALUEstatic float
nextFloat(float startInclusive, float endExclusive)
Returns a random float within the specified range.static int
nextInt()
Returns a random int within 0 - Integer.MAX_VALUEstatic int
nextInt(int startInclusive, int endExclusive)
Returns a random integer within the specified range.static long
nextLong()
Returns a random long within 0 - Long.MAX_VALUEstatic long
nextLong(long startInclusive, long endExclusive)
Returns a random long within the specified range.
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Method Detail
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nextBoolean
public static boolean nextBoolean()
Returns a random boolean value
- Returns:
- the random boolean
- Since:
- 3.5
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nextBytes
public static byte[] nextBytes(int count)
Creates an array of random bytes.
- Parameters:
count
- the size of the returned array- Returns:
- the random byte array
- Throws:
java.lang.IllegalArgumentException
- ifcount
is negative
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nextInt
public static int nextInt(int startInclusive, int endExclusive)
Returns a random integer within the specified range.
- Parameters:
startInclusive
- the smallest value that can be returned, must be non-negativeendExclusive
- the upper bound (not included)- Returns:
- the random integer
- Throws:
java.lang.IllegalArgumentException
- ifstartInclusive > endExclusive
or ifstartInclusive
is negative
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nextInt
public static int nextInt()
Returns a random int within 0 - Integer.MAX_VALUE
- Returns:
- the random integer
- Since:
- 3.5
- See Also:
nextInt(int, int)
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nextLong
public static long nextLong(long startInclusive, long endExclusive)
Returns a random long within the specified range.
- Parameters:
startInclusive
- the smallest value that can be returned, must be non-negativeendExclusive
- the upper bound (not included)- Returns:
- the random long
- Throws:
java.lang.IllegalArgumentException
- ifstartInclusive > endExclusive
or ifstartInclusive
is negative
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nextLong
public static long nextLong()
Returns a random long within 0 - Long.MAX_VALUE
- Returns:
- the random long
- Since:
- 3.5
- See Also:
nextLong(long, long)
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nextDouble
public static double nextDouble(double startInclusive, double endExclusive)
Returns a random double within the specified range.
- Parameters:
startInclusive
- the smallest value that can be returned, must be non-negativeendExclusive
- the upper bound (not included)- Returns:
- the random double
- Throws:
java.lang.IllegalArgumentException
- ifstartInclusive > endExclusive
or ifstartInclusive
is negative
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nextDouble
public static double nextDouble()
Returns a random double within 0 - Double.MAX_VALUE
- Returns:
- the random double
- Since:
- 3.5
- See Also:
nextDouble(double, double)
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nextFloat
public static float nextFloat(float startInclusive, float endExclusive)
Returns a random float within the specified range.
- Parameters:
startInclusive
- the smallest value that can be returned, must be non-negativeendExclusive
- the upper bound (not included)- Returns:
- the random float
- Throws:
java.lang.IllegalArgumentException
- ifstartInclusive > endExclusive
or ifstartInclusive
is negative
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nextFloat
public static float nextFloat()
Returns a random float within 0 - Float.MAX_VALUE
- Returns:
- the random float
- Since:
- 3.5
- See Also:
nextFloat(float, float)
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