MathUtils
This is a utility class with mathematical helper functions.
| Methods |
|---|
| static int |
convertLongToInt(long l)
Convert a long value to an int value.
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| static int |
convertLongToInt(long l)
Convert a long value to an int value. Values larger than the biggest int
value is converted to the biggest int value, and values smaller than the
smallest int value are converted to the smallest int value.
Parameters:
l - the value to convert
Returns:
the converted int value
|
| static byte[] |
generateAlternativeSeed()
Generate a seed value, using as much unpredictable data as possible.
|
| static byte[] |
generateAlternativeSeed()
Generate a seed value, using as much unpredictable data as possible.
Returns:
the seed
|
| static int |
nextPowerOf2(int x)
Get the value that is equal to or higher than this value, and that is a
power of two.
|
| static int |
nextPowerOf2(int x) throws IllegalArgumentException
Get the value that is equal to or higher than this value, and that is a
power of two.
Parameters:
x - the original value
Returns:
the next power of two value
Throws:
IllegalArgumentException - if x < 0 or x > 0x40000000
|
| static void |
randomBytes(byte[] bytes)
Get a number of pseudo random bytes.
|
| static void |
randomBytes(byte[] bytes)
Get a number of pseudo random bytes.
Parameters:
bytes - the target array
|
| static int |
randomInt(int lowerThan)
Get a pseudo random int value between 0 (including and the given value
(excluding).
|
| static int |
randomInt(int lowerThan)
Get a pseudo random int value between 0 (including and the given value
(excluding). The value is not cryptographically secure.
Parameters:
lowerThan - the value returned will be lower than this value
Returns:
the random long value
|
| static int |
roundUpInt(int x, int blockSizePowerOf2)
Round the value up to the next block size.
|
| static int |
roundUpInt(int x, int blockSizePowerOf2)
Round the value up to the next block size. The block size must be a power
of two. As an example, using the block size of 8, the following rounding
operations are done: 0 stays 0; values 1..8 results in 8, 9..16 results
in 16, and so on.
Parameters:
x - the value to be rounded
blockSizePowerOf2 - the block size
Returns:
the rounded value
|
| static long |
roundUpLong(long x, long blockSizePowerOf2)
Round the value up to the next block size.
|
| static long |
roundUpLong(long x, long blockSizePowerOf2)
Round the value up to the next block size. The block size must be a power
of two. As an example, using the block size of 8, the following rounding
operations are done: 0 stays 0; values 1..8 results in 8, 9..16 results
in 16, and so on.
Parameters:
x - the value to be rounded
blockSizePowerOf2 - the block size
Returns:
the rounded value
|
| static byte[] |
secureRandomBytes(int len)
Get a number of cryptographically secure pseudo random bytes.
|
| static byte[] |
secureRandomBytes(int len)
Get a number of cryptographically secure pseudo random bytes.
Parameters:
len - the number of bytes
Returns:
the random bytes
|
| static int |
secureRandomInt(int lowerThan)
Get a cryptographically secure pseudo random int value between 0
(including and the given value (excluding).
|
| static int |
secureRandomInt(int lowerThan)
Get a cryptographically secure pseudo random int value between 0
(including and the given value (excluding).
Parameters:
lowerThan - the value returned will be lower than this value
Returns:
the random long value
|
| static long |
secureRandomLong()
Get a cryptographically secure pseudo random long value.
|
| static long |
secureRandomLong()
Get a cryptographically secure pseudo random long value.
Returns:
the random long value
|
| static void |
warn(String s, Throwable t)
Print a message to system output if there was a problem initializing the
random number generator.
|
| static void |
warn(String s, Throwable t)
Print a message to system output if there was a problem initializing the
random number generator.
Parameters:
s - the message to print
t - the stack trace
|
cachedSecureRandom
The secure random object.
seeded
True if the secure random object is seeded.
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