net.time4j.base

Class MathUtils

java.lang.Object

net.time4j.base.MathUtils

public final class MathUtils
extends Object

Defines some mathematical routines which are needed in calendrical calculations.

Author:

Meno Hochschild

Method Summary

Modifier and Type	Method and Description
static int	floorDivide(int value, int divisor) Returns the largest lower limit of quotient.
static long	floorDivide(long value, int divisor) See floorDivide(int, int).
static int	floorModulo(int value, int divisor) Calculates the remainder based on floorDivide(int, int).
static int	floorModulo(long value, int divisor) See floorModulo(int, int).
static int	safeAdd(int op1, int op2) Sums up the numbers with range check.
static long	safeAdd(long op1, long op2) Sums up the numbers with range check.
static int	safeCast(long num) Performs a safe type-cast to an int-primitive.
static int	safeMultiply(int op1, int op2) Multiplies the numbers with range check.
static long	safeMultiply(long op1, long op2) Multiplies the numbers with range check.
static int	safeNegate(int value) Inverts the number with range check.
static long	safeNegate(long value) Inverts the number with range check.
static int	safeSubtract(int op1, int op2) Subtracts the numbers from each other with range check.
static long	safeSubtract(long op1, long op2) Subtracts the numbers from each other with range check.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

safeCast

public static int safeCast(long num)

Performs a safe type-cast to an int-primitive.

Parameters:

num - long-primitive

Returns:

int as type-cast

Throws:

ArithmeticException - if int-range overflows

safeAdd

public static int safeAdd(int op1,
                          int op2)

Sums up the numbers with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

sum

Throws:

ArithmeticException - if int-range overflows

safeAdd

public static long safeAdd(long op1,
                           long op2)

Sums up the numbers with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

sum

Throws:

ArithmeticException - if long-range overflows

safeSubtract

public static int safeSubtract(int op1,
                               int op2)

Subtracts the numbers from each other with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

difference

Throws:

ArithmeticException - if int-range overflows

safeSubtract

public static long safeSubtract(long op1,
                                long op2)

Subtracts the numbers from each other with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

difference

Throws:

ArithmeticException - if long-range overflows

safeMultiply

public static int safeMultiply(int op1,
                               int op2)

Multiplies the numbers with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

product

Throws:

ArithmeticException - if int-range overflows

safeMultiply

public static long safeMultiply(long op1,
                                long op2)

Multiplies the numbers with range check.

Parameters:

op1 - first operand

op2 - second operand

Returns:

product

Throws:

ArithmeticException - if long-range overflows

safeNegate

public static int safeNegate(int value)

Inverts the number with range check.

Parameters:

value - value to be negated

Returns:

the expression -value

Throws:

ArithmeticException - if int-range overflows

safeNegate

public static long safeNegate(long value)

Inverts the number with range check.

Parameters:

value - value to be negated

Returns:

the expression -value

Throws:

ArithmeticException - if long-range overflows

floorDivide

public static int floorDivide(int value,
                              int divisor)

Returns the largest lower limit of quotient.

Examples:

• floorDivide(2, 2) == 1
• floorDivide(1, 2) == 0
• floorDivide(0, 2) == 0
• floorDivide(-1, 2) == -1
• floorDivide(-2, 2) == -1
• floorDivide(-3, 2) == -2

Parameters:

value - numerator

divisor - divisor

Returns:

quotient as result of division

floorDivide

public static long floorDivide(long value,
                               int divisor)

See floorDivide(int, int).

Parameters:

value - numerator

divisor - divisor

Returns:

quotient as result of division

floorModulo

public static int floorModulo(int value,
                              int divisor)

Calculates the remainder based on floorDivide(int, int).

Examples:

• floorModulo(2, 2) == 0
• floorModulo(1, 2) == 1
• floorModulo(0, 2) == 0
• floorModulo(-1, 2) == 1
• floorModulo(-2, 2) == 0
• floorModulo(-3, 2) == 1

Parameters:

value - numerator

divisor - divisor

Returns:

remainder of division (never negative if divisor is positive)

floorModulo

public static int floorModulo(long value,
                              int divisor)

See floorModulo(int, int).

Parameters:

value - numerator

divisor - divisor

Returns:

remainder of division (never negative if divisor is positive)