net.enilink.commons.util

Class ValueUtils

java.lang.Object

net.enilink.commons.util.ValueUtils

public class ValueUtils
extends Object

Author:

Ken Wenzel

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<Class<?>,Object>	defaultValues
protected Map<Class<?>,ValueType>	typeMap

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ValueUtils()

Method Summary

Modifier and Type	Method and Description
Object	add(Object v1, Object v2) Adds the two objects given.
BigDecimal	bigDecValue(Object value) Evaluates the given object as a BigDecimal.
BigInteger	bigIntValue(Object value) Evaluates the given object as a BigInteger.
Boolean	booleanValue(Object value)
int	compareWithConversion(Object v1, Object v2)
int	compareWithConversion(Object v1, Object v2, Number epsilon)
Object	convertValue(Class<?> toType, Object value, Object defaultValue) Returns the value converted numerically to the given class type.
Number	createInteger(ValueType type, long value) Returns a new Number object of an appropriate type to hold the given integer value.
Number	createReal(ValueType type, double value) Returns a new Number object of an appropriate type to hold the given real value.
Object	divide(Object v1, Object v2) Divides the first argument by the second
double	doubleValue(Object value) Evaluates the given object as a double-precision floating-point number.
static ValueUtils	getInstance()
ValueType	getNumericType(ValueType t1, ValueType t2, boolean canBeNonNumeric) Returns the constant from the NumericTypes interface that best expresses the type of an operation, which can be either numeric or not, on the two given types.
ValueType	getType(Object value)
long	longValue(Object value) Evaluates the given object as a long integer.
Object	multiply(Object v1, Object v2) Multiplies v1 times v2.
Object	negate(Object v1) Negates v1.
Object	remainder(Object v1, Object v2) Returns the number of the first argument, v1, divided by the second number's remainder (modulus).
String	stringValue(Object value, boolean trim) Evaluates the given object as a String and trims it if the trim flag is true.
Object	subtract(Object v1, Object v2) Subtracts v2 from v1.

Methods inherited from class java.lang.Object

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

Field Detail

typeMap

protected Map<Class<?>,ValueType> typeMap

defaultValues

protected Map<Class<?>,Object> defaultValues

Constructor Detail

ValueUtils

protected ValueUtils()

Method Detail

getInstance

public static ValueUtils getInstance()

getType

public ValueType getType(Object value)

getNumericType

public ValueType getNumericType(ValueType t1,
                                ValueType t2,
                                boolean canBeNonNumeric)

Returns the constant from the NumericTypes interface that best expresses the type of an operation, which can be either numeric or not, on the two given types.

Parameters:

t1 - one argument type to an operator

t2 - the other argument type

canBeNonNumeric - whether the operator can be interpreted as non-numeric

Returns:

the appropriate constant from the NumericTypes interface

compareWithConversion

public int compareWithConversion(Object v1,
                                 Object v2)

compareWithConversion

public int compareWithConversion(Object v1,
                                 Object v2,
                                 Number epsilon)

stringValue

public String stringValue(Object value,
                          boolean trim)

Evaluates the given object as a String and trims it if the trim flag is true.

Parameters:

value - an object to interpret as a String

trim - if true this returned string value is trimmed of whitespace using String.trim().

Returns:

the String value implied by the given object as returned by the toString() method, or "null" if the object is null.

longValue

public long longValue(Object value)
               throws NumberFormatException

Evaluates the given object as a long integer.

Parameters:

value - an object to interpret as a long integer

Returns:

the long integer value implied by the given object

Throws:

NumberFormatException - if the given object can't be understood as a long integer

doubleValue

public double doubleValue(Object value)
                   throws NumberFormatException

Evaluates the given object as a double-precision floating-point number.

Parameters:

value - an object to interpret as a double

Returns:

the double value implied by the given object

Throws:

NumberFormatException - if the given object can't be understood as a double

bigDecValue

public BigDecimal bigDecValue(Object value)
                       throws NumberFormatException

Evaluates the given object as a BigDecimal.

Parameters:

value - an object to interpret as a BigDecimal

Returns:

the BigDecimal value implied by the given object

Throws:

NumberFormatException - if the given object can't be understood as a BigDecimal

bigIntValue

public BigInteger bigIntValue(Object value)
                       throws NumberFormatException

Evaluates the given object as a BigInteger.

Parameters:

value - an object to interpret as a BigInteger

Returns:

the BigInteger value implied by the given object

Throws:

NumberFormatException - if the given object can't be understood as a BigInteger

booleanValue

public Boolean booleanValue(Object value)

add

public Object add(Object v1,
                  Object v2)

Adds the two objects given. For numeric values this will add them numerically; for one of the arguments being non-numeric this will catenate them as Strings.

Parameters:

v1 - First addend

v2 - Second addend

Returns:

v1 + v2 or concatenated String

subtract

public Object subtract(Object v1,
                       Object v2)

Subtracts v2 from v1.

Parameters:

v1 - Value to be subtracted from.

v2 - Value to be subtracted from v1.

Returns:

v1 - v2

negate

public Object negate(Object v1)

Negates v1.

Parameters:

v1 - Value to be negated.

Returns:

-v1

multiply

public Object multiply(Object v1,
                       Object v2)

Multiplies v1 times v2.

Parameters:

v1 - First multiplicand

v2 - Second multiplicand

Returns:

v1 * v2

divide

public Object divide(Object v1,
                     Object v2)

Divides the first argument by the second

Parameters:

v1 - Dividend

v2 - Divisor

Returns:

Value of v1 / v2.

remainder

public Object remainder(Object v1,
                        Object v2)

Returns the number of the first argument, v1, divided by the second number's remainder (modulus).

Parameters:

v1 - Dividend

v2 - Divisor

Returns:

Remainder of dividing v1 / v2.

createInteger

public Number createInteger(ValueType type,
                            long value)

Returns a new Number object of an appropriate type to hold the given integer value. The type of the returned object is consistent with the given type argument, which is a constant from the NumericTypes interface.

Parameters:

type - the nominal numeric type of the result

value - the integer value to convert to a Number object

Returns:

a Number object with the given value, of type implied by the type argument

createReal

public Number createReal(ValueType type,
                         double value)

Returns a new Number object of an appropriate type to hold the given real value. The type of the returned object is always either Float or Double, and is only Float if the given type tag (a constant from the NumericTypes interface) is FLOAT.

Parameters:

type - the nominal numeric type of the result

value - the real value to convert to a Number object

Returns:

a Number object with the given value, of type implied by the type argument

convertValue

public Object convertValue(Class<?> toType,
                           Object value,
                           Object defaultValue)

Returns the value converted numerically to the given class type.

Parameters:

toType - class type to be converted to

value - an object to be converted to the given type

defaultValue - value returned in the event that no conversion is possible to the given type

Returns:

converted value of the type given, or defaultValue if the value cannot be converted to the given type.